53 results on '"Sun, Hang"'
Search Results
2. Development of Polymeric Micelles of Oleanolic Acid and Evaluation of Their Clinical Efficacy
- Author
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Bungchul Shin, Sun Hang Cho, Hee Seon Yang, Joo Young An, Na Rae Park, Tae-sung Koo, and Eun Hee Lee
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Materials science ,Polymers ,02 engineering and technology ,010402 general chemistry ,Penetration ,01 natural sciences ,chemistry.chemical_compound ,Ingredient ,lcsh:TA401-492 ,General Materials Science ,Solubility ,Oleanolic acid ,Active ingredient ,chemistry.chemical_classification ,Chromatography ,Nano Express ,Polymer ,Permeation ,Poloxamer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,chemistry ,Formulation ,lcsh:Materials of engineering and construction. Mechanics of materials ,Particle size ,0210 nano-technology ,Stability ,Delivery - Abstract
Oleanolic acid has been used only as a subsidiary agent in cosmetic products. The aim of the study is to show the effect of oleanolic acid as an active ingredient for the alleviation of wrinkles in humans and to develop a polymeric micelle formulation that enables poorly soluble oleanolic acid to be used as a main ingredient in cosmetic products for reducing wrinkles. The solubility of oleanolic acid was evaluated in solubilizers, surfactants, and polymers. The particle sizes and shapes of polymeric micelles containing oleanolic acid were evaluated by electrophoretic light scattering spectrophotometer and scanning electron cryomicroscopy. Encapsulation efficiency and skin permeation were measured by HPLC. Stability of the polymeric micelles stored at 40 °C for 3 months was evaluated by visual observation, particle size measurement, and oleanolic acid content measurement. Polymeric micelles in final product ampoule form were applied around the eyes of 23 female subjects for 8 weeks. Five skin parameters were evaluated by optical profilometry every 4 weeks for 8 weeks. In addition, professionals made visual observations of the skin and a human skin irritation study was conducted. Polymeric micelles of oleanolic acid with a particle size of less than 100 nm were prepared using Capryol 90® and poloxamer. The skin permeation rate of the oleanolic acid in the polymeric micelles was higher than that in the other solutions made of oleanolic acid dispersed in 2 different surfactants. No significant changes in particle size, color, or oleanolic acid content were observed, and the polymeric micelles stored at 40 °C for 3 months did not undergo phase separation. After 8 weeks of application, skin irritation had not developed and all five parameters evaluated by optical profilometry as well as the visual evaluation scores were significantly improved. This study showed that the polymeric micelles of oleanolic acid prepared in this study were stable and effective at alleviating wrinkles in humans as the principal active ingredient. Based on these findings, it is expected that polymeric micelles of oleanolic acid can be widely used in cosmetic applications.
- Published
- 2019
3. Multifunctional ultrasmall superparamagnetic iron oxide nanoparticles as a theranostic agent
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Hasoo Seong, Jiyoung Yoon, and Sun Hang Cho
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biology ,Iron oxide ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,biology.organism_classification ,01 natural sciences ,Imaging agent ,0104 chemical sciences ,law.invention ,HeLa ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Confocal microscopy ,law ,parasitic diseases ,Amphiphile ,Copolymer ,0210 nano-technology ,Cytotoxicity ,Nuclear chemistry - Abstract
A new theranostic ultrasmall superparamagnetic iron oxide nanoparticle (USPIONP)—consisting of an iron oxide nanoparticle (IONP) core, amphiphilic poly(aspartic acid) graft copolymer (P), and a model anticancer drug, epirubicin (EPI)—was developed and characterized. The graft copolymer P, poly(2-hydroxyethylaspartamide)-mPEG-C16, was synthesized by a polysuccinimide ring-opening reaction. The P-IONP, the IONP core of which was coated with polymer P, was synthesized using a co-precipitation method. The P-IONP was a USPIONP with an IONP core of diameter 6–9 nm and a hydrodynamic diameter of 41 nm. The EPI-loaded P-IONP (EPI-P-IONP) had a hydrodynamic diameter of 53 nm. The remarkably high relaxivity, r2, of 605.5 s−1 mM−1 of EPI-P-IONP corresponded to magnetic resonance contrast enhancement 2.7-fold that of a commercial contrast agent. The EPI encapsulation efficiency was 81%, and EPI was released from EPI-P-IONP in a sustained manner. P-IONP had negligible cytotoxicity against HeLa cells, while cytotoxicity increased in an EPI-dose-dependent manner after 4 h incubation with EPI-P-IONP. Cellular uptake of EPI from EPI-P-IONP was comparable to that of free EPI, as determined by flow cytometry. Confocal microscopy confirmed nuclear uptake of EPI released from EPI-P-IONP. These results suggest that the P-IONP has potential as an imaging agent and a therapeutic agent, and thus as a theranostic agent.
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- 2017
4. Oxidation Characteristics and Electrical Properties of Doped Mn-Co Spinel Reaction Layer for Solid Oxide Fuel Cell Metal Interconnects
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Lai Yongbiao, Sun Hang, Yu Zhang, P.Y. Guo, Yuxin Wang, and Yong Shao
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Materials science ,lanthanum ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Metal ,chemistry.chemical_compound ,Chromium ,Coating ,copper ,coating ,in-situ oxidation ,electrical properties ,Materials Chemistry ,Lanthanum ,Spinel ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Microstructure ,0104 chemical sciences ,Surfaces, Coatings and Films ,chemistry ,Chemical engineering ,lcsh:TA1-2040 ,visual_art ,engineering ,visual_art.visual_art_medium ,Solid oxide fuel cell ,0210 nano-technology ,lcsh:Engineering (General). Civil engineering (General) - Abstract
To prevent Cr poisoning of the cathode and to retain high conductivity during solid oxide fuel cell (SOFC) operation, Cu or La doped Co-Mn coatings on a metallic interconnect is deposited and followed by oxidation at 750 °C. Microstructure and composition of coatings after preparation and oxidation is analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). High energy micro arc alloying process, a low cost technique, is used to prepare Cu or La doped Co-Mn coatings with the metallurgical bond. When coatings oxidized at 750 °C in air for 20 h and 100 h, Co3O4 is the main oxide on the surface of Co-38Mn-2La and Co-40Mn coatings, and (Co,Mn)3O4 spinel continues to grow with extended oxidation time. The outmost scales of Co-33Mn-17Cu are mainly composed of cubic MnCo2O4 spinel with Mn2O3 after oxidation for 20 h and 100 h. The average thickness of oxide coatings is about 60–70 μm after oxidation for 100 h, except that Co-40Mn oxide coatings are a little thicker. Area-specific resistance of Cu/La doped Co-Mn coatings are lower than that of Co-40Mn coating. (Mn,Co)3O4/MnCo2O4 spinel layer is efficient at blocking the outward diffusion of chromium and iron.
- Published
- 2018
5. Biodistribution of newly synthesized PHEA-based polymer-coated SPION in Sprague Dawley rats as magnetic resonance contrast agent
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Ha Young Lee, Junsung Park, Dae Chul Ha, Hee Jun Park, Sun Hang Cho, Wonkyung Cho, Youn Woong Choi, Kwang Ho Cha, and Sung Joo Hwang
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Male ,Biocompatible polymers ,Biodistribution ,Materials science ,Superparamagnetic iron oxide nanoparticles ,Biophysics ,Iron oxide ,Pharmaceutical Science ,Contrast Media ,Bioengineering ,liver ,Rats sprague dawley ,polyhydroxyethylaspartamide ,Biomaterials ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,International Journal of Nanomedicine ,Drug Discovery ,Sprague dawley rats ,Animals ,Tissue Distribution ,Tissue distribution ,pharmacokinetic ,Magnetite Nanoparticles ,Original Research ,chemistry.chemical_classification ,Organic Chemistry ,SPION ,General Medicine ,Polymer ,Anatomy ,Rats ,chemistry ,radiolabeled ,Administration, Intravenous ,Female ,Nuclear chemistry - Abstract
Junsung Park,1,2,* Wonkyung Cho,1,2,* Hee Jun Park,1,2 Kwang-Ho Cha,1,2 Dae-Chul Ha,2,5 Youn-Woong Choi,5 Ha-Young Lee,3 Sun-Hang Cho,5 Sung-Joo Hwang1,41Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; 2College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea; 3Biomaterials Laboratory, Korea Research Institutes of Chemical Technology, Daejeon, Republic of Korea; 4College of Pharmacy, Yonsei University, Incheon, Republic of Korea; 5Korea United Pharm Inc, Seoul, Republic of Korea *These authors contributed equally to this workObjectives: The purpose of this study was to observe the pharmacokinetic behavior of newly synthesized biocompatible polymers based on polyhydroxyethylaspartamide (PHEA) to be used to coat an iron oxide core to make superparamagnetic iron oxide nanoparticles (SPION).Materials and methods: The isotopes [14C] and [59Fe] were used to label the polymer backbone (CLS) and iron oxide core (FLS), respectively. In addition, unradiolabeled cold superparamagnetic iron oxide nanoparticles (SPION/ULS) were synthesized to characterize particle size by dynamic light scattering, morphology by transmission electron microscopy, and in vivo magnetic resonance imaging (MRI). CLS and FLS were used separately to investigate the behavior of both the synthesized polymer and [Fe] in Sprague Dawley (SD) rats, respectively. Because radioactivity of the isotopes was different by β for CLS and γ for FLS, synthesis of the samples had to be separately prepared.Results: The mean particle size of the ULS was 66.1 nm, and the biodistribution of CLS concentrations in various organs, in rank order of magnitude, was liver > kidney > small intestine > other. The biodistribution of FLS concentrations was liver > spleen > lung > other. These rank orders show that synthesized SPION mainly accumulates in the liver. The differences in the distribution were caused by the SPION metabolism. Radiolabeled polymer was metabolized by the kidney and excreted mainly in the urine; [59Fe] was recycled for erythrocyte production in the spleen and excreted mainly in the feces. The MR image of the liver after intravenous injection demonstrated that [Fe] effectively accumulated in the liver and exhibited high-contrast enhancement on T2-weighted images.Conclusion: This newly synthesized, polymer-coated SPION appears to be a promising candidate for use as a liver-targeted, biocompatible iron oxide MR imaging agent.Keywords: SPION, radiolabeled, polyhydroxyethylaspartamide, pharmacokinetic, liverCorrigendum for this paper has been published
- Published
- 2013
6. Ethosomes and Transfersomes for Topical Delivery of Ginsenoside Rh1 from Red Ginseng: Characterization and In Vitro Evaluation
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Cheong-Weon Cho, Jae-Hwan Choi, Young-Beob Yu, Je-Jung Yun, and Sun-Hang Cho
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Protopanaxatriol ,Liposome ,Materials science ,Metabolite ,Vesicle ,Biomedical Engineering ,Bioengineering ,General Chemistry ,Permeation ,Pharmacology ,Condensed Matter Physics ,Transfersome ,chemistry.chemical_compound ,Ginseng ,chemistry ,Ginsenoside ,General Materials Science - Abstract
Red ginseng (the steamed root of Panax ginseng C. A. Mayer), which contains ginsenosides as its main constituents, is frequently used to treat tumor, inflammation, diabetes, stress and acquired immunodeficiency syndrome in Asian countries. Ginsenoside Rhl, a bacterial metabolite of ginsenoside Rgl, is a protopanaxatriol type of ginsenosides. Liposomes do not deeply penetrate the skin and remain confined to the stratum corneum.Thus, new vesicular colloidal carriers such as ethosomes and transfersomes have been developed as an enhanced type of liposomes, recently. The aim of this study was to improve the topical delivery of ginsenoside Rhl isolated from red ginseng employing new vesicular system of ethosomes and transfersomes compared to conventional liposome. Characterization of ginsenoside Rhl-loaded vesicles were prepared and evaluated for particle size, zeta potential, entrapment efficiency (% EE), and transmission electron microscopy (TEM) studies. In addition, skin permeation profile was obtained using frantz diffusion cells and rat dorsal skin treated with ethosome and transfersome compared with conventional iposome. The size of vesicles range from 108.5 to 322.9 nm, and negatively charged from -20.95 to -31.37 mV. The % EE of ginsenoside Rh1 was obtained between 45.0 to 65.0%. Transfersomes provided a significantly higher skin permeation of ginsenoside Rhl compared to ethosome and conventional liposome. Therefore, based on the current study, ginsenoside Rhl-loaded transfersomes can act as a topical therapeutic effects potential.
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- 2015
7. Ultrasound-Triggered Drug Release of Hydroxyapatite Coated Liposomes
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Byung Cheol Shin, Sung Keun Cho, Kun Han, Tae In Wee, Sun Hang Cho, Jeung Ha, and Hee Dong Han
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Drug ,Liposome ,Chromatography ,business.industry ,media_common.quotation_subject ,Ultrasound ,chemistry.chemical_element ,Calcium ,chemistry.chemical_compound ,chemistry ,Chemistry (miscellaneous) ,Phosphatidylcholine ,medicine ,Chemical Engineering (miscellaneous) ,Doxorubicin ,Drug carrier ,business ,Phosphoric acid ,media_common ,medicine.drug - Abstract
Liposomes, which can deliver payload at target site, have been studied as drug carrier. However, conventional liposomes have limitation for drug release at target site. Therefore, we developed hydroxyapatite (HA) coated ultrasound sen- sitive liposomes to increase drug release at target site and to enhance stability in blood stream. Control liposome was prepared using hydrogenated soy phosphatidylcholine (HSPC) and cholesterol, and then we assessed HA coating on the surface of con- trol liposomes using calcium acetate, phosphoric acid, and 25% ammonium solution. Doxorubicin was used as a model drug. Size of HA coated liposomes was 120 nm and encapsulation efficiency of doxorubicin in liposomes was up to 95%. Size of HA coated liposomes are not changed in 30% serum solution, however, the control liposomes was 1.4 fold increased. After ultrasound triggered drug release from liposomes, intracellular efficiency of drug released from HA coated liposomes was 3 fold increased compared to control liposomes. In this study, we developed ultrasound sensitive liposomes to enhance drug release, which will be applied in controlled drug release at disease site.
- Published
- 2013
8. Dual Functional Gd(III)-DOTA Liposomes for Cancer Therapy and Diagnosis as a Theragnostic Carrier
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Hasoo Seong, Byung Cheol Shin, Sun Hang Cho, Hee Dong Han, and Suk Hyun Jung
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Liposome ,business.industry ,Gadolinium ,Ultrasound ,Cancer therapy ,Cancer ,chemistry.chemical_element ,General Chemistry ,Pharmacology ,medicine.disease ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Human disease ,chemistry ,medicine ,DOTA ,Doxorubicin ,business ,medicine.drug - Abstract
Development of dual functional liposome has been studied for cancer theragnostics. Therefore, we focused on ultrasound-sensitive liposomes with doxorubicin (DOX) and gadolinium (Gd) as a theragnostic carrier having a potential for cancer therapy and diagnosis. In this study, Gd(III)-DOTA-modified sonosensitive liposomes (GL) was developed using chemically synthesized Gd(III)-DOTA-DPPE lipid. Sonosensitivity of GL to 1 MHz ultrasound induced 25% of DOX release. The relaxivities () of GL were , which was higher than that of MR-bester. Intracellular delivery of DOX from GL by ultrasound irradiation was evaluated according to ultrasound intensity, resulting in increase of uptake of DOX released from ultrasound-triggered GLs compared to GL3 or Doxil without ultrasound. Taken together, this study shows that the paramagnetic and sonosensitive liposomes, GL, is a novel and highly effective delivery system for drug with the potential for broad applications in human disease.
- Published
- 2013
9. Multi-core vesicle nanoparticles for controlled delivery of protein drug
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Hyesung Jeon, Ick Chan Kwon, Sun Hang Cho, Kwangmeyung Kim, Keun Sang Oh, Seung Ki Kim, Soon Hong Yuk, and Jin Ho Lee
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Materials science ,Vesicle fusion ,Chromatography ,Polymers and Plastics ,General Chemical Engineering ,Vesicle ,Organic Chemistry ,technology, industry, and agriculture ,Nanochemistry ,Nanoparticle ,Poloxamer ,Polymer engineering ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,PEG ratio ,Materials Chemistry ,Ethylene glycol ,health care economics and organizations - Abstract
The Pluronic/poly(ethylene glycol) composite nanoparticles (NPs) composed of Pluronic F-68, liquid poly(ethylene glycol) (PEG; molecular weight, 400) and human growth hormone (hGH) were stabilized with the vesicle fusion. When hGH-loaded Pluronic/PEG composite NPs were mixed with vesicles in the aqueous medium, hGH-loaded Pluronic/PEG composite NPs were incorporated into vesicles to form multi-core vesicle NPs. The morphology and size distribution of multi-core vesicle NPs were observed using field emission scanning electron microscopy, cryo-transmission electron microscopy, and a particle size analyzer. When multi-core vesicle NPs were applied as a delivery system for the protein drug, a sustained release pattern of hGH was observed.
- Published
- 2012
10. Preparation and Characterization of Poly(ethylene glycol) Based Pranlukast Solid Dispersion
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Youngjin Kim, Jun Seok Hwang, Kang Moo Huh, Sun-Hang Cho, and Hyeong-Eun Kim
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Chromatography ,Materials science ,Polymers and Plastics ,General Chemical Engineering ,Poloxamer ,Pranlukast ,Amorphous solid ,chemistry.chemical_compound ,Crystallinity ,chemistry ,Chemical engineering ,PEG ratio ,Materials Chemistry ,medicine ,Solubility ,Ethylene glycol ,Dissolution ,medicine.drug - Abstract
In this study, poly(ethylene glycol) (PEG) was used as a hydrophilic polymer carrier to develop solid dispersion formulations for enhancing solubility and dissolution rate of pranlukast, one of poorly soluble drugs that has been broadly used for the treatment of asthma. PEG based solid dispersions with or without poloxamer were prepared by hot melting and solvent evaporation methods. The resultant solid dispersions were characterized by DSC and powder X-ray measurements, and their morphological properties were observed to be partially changed to amorphous state with reduced crystallinity. Dissolution and solubility tests showed that the solubility and dissolution rate of the solid dispersions were significantly enhanced. The solid dispersion formulation prepared by the hot melting method with a chemical composition of pranlukast:PEG:poloxamer = 1:5:1 demonstrated the most enhanced solubility and dissolution rate. The results suggest that the solid dispersions based on PEG and poloxamer are promising systems for the enhancement of solubility and bioavailability of pranlukast.
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- 2012
11. Glycol Chitosan/Heparin Immobilized Iron Oxide Nanoparticles with a Tumor-Targeting Characteristic for Magnetic Resonance Imaging
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Soon Hong Yuk, Byung Kook Kwak, Beom Suk Lee, Ick Chan Kwon, Sang Yoon Kim, Sun Hang Cho, Kwangmeyung Kim, and Keun Sang Oh
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Anions ,Male ,Spectrophotometry, Infrared ,Polymers and Plastics ,Cell Survival ,Inorganic chemistry ,Composite number ,Iron oxide ,Polysorbates ,Ionic bonding ,Bioengineering ,Ferric Compounds ,Fluorescence ,Biomaterials ,Mice ,chemistry.chemical_compound ,Cations ,Cell Line, Tumor ,Spectrophotometry ,Materials Chemistry ,medicine ,Animals ,Tissue Distribution ,Particle Size ,Chitosan ,medicine.diagnostic_test ,Heparin ,Temperature ,technology, industry, and agriculture ,Cationic polymerization ,equipment and supplies ,Magnetic Resonance Imaging ,Xenograft Model Antitumor Assays ,Radiography ,chemistry ,Carcinoma, Squamous Cell ,Microscopy, Electron, Scanning ,Nanoparticles ,Gold ,Particle size ,Iron oxide nanoparticles ,Nuclear chemistry - Abstract
We described the preparation of the glycol chitosan/heparin immobilized iron oxide nanoparticles (composite NPs) as a magnetic resonance imaging agent with a tumor-targeting characteristic. The iron oxide nanoseeds used clinically as a magnetic resonance imaging agent were immobilized into the glycol chitosan/heparin network to form the composite NPs. To induce the ionic interaction between the iron oxide nanoseeds and glycol chitosan, gold was deposited on the surface of iron oxide nanoseeds. After the immobilization of gold-deposited iron oxide NPs into the glycol chitosan network, the NPs were stabilized with heparin based on the ionic interaction between cationic glycol chitosan and anionic heparin. FE-SEM (field emission-scanning electron microscopy) and a particle size analyzer were used to observe the formation of the stabilized composite NPs, and a Jobin-Yvon Ultima-C inductively coupled plasma-atomic emission spectrometer (ICP-AES) was used to measure the contents (%) of formed iron oxide nanoseeds as a function of reaction temperature and formed gold deposited on the iron oxide nanoparticles. We also evaluated the time-dependent excretion profile, in vivo biodistribution, circulation time, and tumor-targeting ability of the composite NPs using a noninvasive NIR fluorescence imaging technology. To observe the MRI contrast characteristic, the composite NPs were injected into the tail veins of tumor-bearing mice to demonstrate their selective tumoral distribution. The MR images were collected with conventional T(2)-weighted spin echo acquisition parameters.
- Published
- 2011
12. Paclitaxel-loaded Pluronic nanoparticles formed by a temperature-induced phase transition for cancer therapy
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Ick Chan Kwon, Kwangmeyung Kim, Ji Yung Song, Sun Hang Cho, Sang Yoon Kim, Bum Suk Lee, Hyesung Jeon, Soon Hong Yuk, and Keun Sang Oh
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Male ,Paclitaxel ,Cell Survival ,Pharmaceutical Science ,Nanoparticle ,Excipient ,Poloxamer ,Polyethylene glycol ,Phase Transition ,Polyethylene Glycols ,Mice ,chemistry.chemical_compound ,X-Ray Diffraction ,Cell Line, Tumor ,Neoplasms ,PEG ratio ,medicine ,Animals ,Humans ,Nanotechnology ,Organic chemistry ,Microparticle ,chemistry.chemical_classification ,Drug Carriers ,Temperature ,Polymer ,Antineoplastic Agents, Phytogenic ,chemistry ,Chemical engineering ,Nanoparticles ,Polymer blend ,medicine.drug - Abstract
We prepared nanoparticles by a temperature-induced phase transition in a mixture of Pluronic F-68 and liquid PEG (polyethylene glycol, molecular weight: 400) containing paclitaxel (PTX) with a fast, simple, continuous and solvent-free process. The liquid PEG is used as solubilizer of PTX and the polymer for the encapsulation of PTX is composed of Pluronic F-68. At the phase transition temperature, the polymer mixture was changed to the liquid phase, and stirring the liquid polymer mixture formed emulsions composed of PEG containing PTX and liquidized Pluronic F-68. On the nanometer scale, PEG containing PTX was encapsulated by Pluronic F-68 by cooling to 0 °C to form Pluronic nanoparticles. The morphology and size distribution of the prepared Pluronic nanoparticles were observed using FE-SEM and TEM, and a particle size analyzer and cryo-TEM were used to observe the shape of paclitaxel-loaded Pluronic nanoparticles in an aqueous state. To apply Pluronic nanoparticles as a delivery system for cancer therapy, the release pattern of PTX, a model anti-cancer drug, was observed and the tumor growth was monitored by injecting the PTX-loaded Pluronic nanoparticles into the tail veins of tumor-bearing mice. We also evaluated the time-dependent excretion profile, in vivo biodistribution, circulation time, and tumor targeting ability of PTX-loaded Pluronic nanoparticles using non-invasive live animal imaging technology. In the early stage within 7 h of release, the loaded PTX was rapidly released and the sustained release was observed for up to 48 h. In vivo studies, PTX-loaded Pluronic nanoparticles were observed with higher anti-tumor efficacy compared with PTX formulated in Cremophor EL.
- Published
- 2010
13. Core/Shell Nanoparticles for pH-Sensitive Delivery of Doxorubicin
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Kyung Eun Lee, Keun Sang Oh, Sun Hang Cho, Sung Sik Han, Yun Sik Um, Soon Hong Yuk, Jin Ho Lee, and Dongmin Kim
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food.ingredient ,Materials science ,Biomedical Engineering ,Nanoparticle ,Bioengineering ,Poloxamer ,Lecithin ,chemistry.chemical_compound ,Drug Delivery Systems ,food ,Microscopy, Electron, Transmission ,Lecithins ,Copolymer ,General Materials Science ,Propylene oxide ,Particle Size ,Antibiotics, Antineoplastic ,Aqueous solution ,Ethylene oxide ,Trehalose ,General Chemistry ,Hydrogen-Ion Concentration ,Condensed Matter Physics ,chemistry ,Chemical engineering ,Doxorubicin ,Drug delivery ,Nanoparticles - Abstract
Core/shell nanoparticles with lipid core were prepared and characterized as pH-sensitive delivery system of anticancer drug. The lipid core is composed of drug-loaded lecithin and the polymeric shell is composed of Pluronics (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) tri-block copolymer, F-127). Based on the preparation method in the previous report by us, the freeze-drying of drug-loaded lecithin was performed in the F-127 aqueous solution containing trehalose used as a cryoprotectant to form stabilized core/shell nanoparticles. For the application of core/shell nanoparticles as a pH-sensitive drug delivery system for anticancer drug, doxorubicin was loaded into the core/shell nanoparticles and the drug loading amount and drug release behavior in response to pH change were observed.
- Published
- 2010
14. Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents
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Hyo Jeong Kim, Ha Young Lee, Soon Hong Yuk, Sang Young Jeong, Hasoo Seong, Sun Hang Cho, Byung Cheol Shin, Sung Joo Hwang, and Byung Kook Kwak
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Materials science ,Gadolinium ,MRI contrast agent ,chemistry.chemical_element ,Ethylenediamine ,Micelle ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Materials Science(all) ,Dynamic light scattering ,Amphiphile ,lcsh:TA401-492 ,medicine ,Nanotechnology ,General Materials Science ,Chemistry/Food Science, general ,Micelles ,Nano Express ,Material Science ,medicine.diagnostic_test ,Engineering, General ,Materials Science, general ,Magnetic resonance imaging ,Condensed Matter Physics ,Physics, General ,chemistry ,PHEA derivatives ,Proton NMR ,Molecular Medicine ,Nanoparticles ,lcsh:Materials of engineering and construction. Mechanics of materials ,Gd contrast agent - Abstract
Biocompatible poly-[N-(2-hydroxyethyl)-d,l-aspartamide]-methoxypoly(ethyleneglycol)-hexadecylamine (PHEA-mPEG-C16) conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd) via ethylenediamine (ED) was synthesized as a magnetic resonance imaging (MRI) contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Micelle size and shape were examined by dynamic light scattering (DLS) and atomic force microscopy (AFM). Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.
- Published
- 2010
15. Polyethylene glycol-complexed cationic liposome for enhanced cellular uptake and anticancer activity
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Hasoo Seong, Kyu Sung Jeong, Sun Hang Cho, Byung Cheol Shin, Suk Hyun Jung, and Soon Hwa Jung
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Magnetic Resonance Spectroscopy ,Time Factors ,Cell Survival ,Chemistry, Pharmaceutical ,Drug Compounding ,Melanoma, Experimental ,Pharmaceutical Science ,macromolecular substances ,Polyethylene glycol ,Adenocarcinoma ,Polyethylene Glycols ,Rats, Sprague-Dawley ,Mice ,chemistry.chemical_compound ,In vivo ,Cell Line, Tumor ,PEG ratio ,Zeta potential ,Animals ,Humans ,Technology, Pharmaceutical ,Cationic liposome ,Particle Size ,Ovarian Neoplasms ,Drug Carriers ,Mice, Inbred BALB C ,Liposome ,Antibiotics, Antineoplastic ,Dose-Response Relationship, Drug ,technology, industry, and agriculture ,Biological Transport ,Flow Cytometry ,Xenograft Model Antitumor Assays ,Rats ,Tumor Burden ,Microscopy, Fluorescence ,chemistry ,Biochemistry ,Doxorubicin ,Injections, Intravenous ,Liposomes ,Drug delivery ,Biophysics ,Female ,Drug carrier - Abstract
Liposomes as one of the efficient drug carriers have some shortcomings such as their relatively short blood circulation time, fast clearance from human body by reticuloendothelial system (RES) and limited intracellular uptake to target cells. In this study, polyethylene glycol (PEG)-complexed cationic liposomes (PCL) were prepared by ionic complex of cationically charged liposomes with carboxylated polyethylene glycol (mPEG-COOH). The cationic liposomes had approximately 98.6+/-1.0 nm of mean particle diameter and 45.5+/-1.1 mV of zeta potential value. While, the PCL had 110.1+/-1.2 nm of mean particle diameter and 18.4+/-0.8 mV of zeta potential value as a result of the ionic complex of mPEG-COOH with cationic liposomes. Loading efficiency of model drug, doxorubicin, into cationic liposomes or PCL was about 96.0+/-0.7%. Results of intracellular uptake evaluated by flow cytometry and fluorescence microscopy studies showed higher intracellular uptake of PCL than that of Doxil. In addition, in vitro cytotoxicity of PCL was comparable to cationic liposomes. In pharmacokinetic study in rats, PCL showed slightly lower plasma level of DOX than that of Doxil. In vivo antitumor activity of DOX-loaded PCL was comparable to that of Doxil against human SKOV-3 ovarian adenocarcinoma xenograft rat model. Consequently, the PCL, of which surface was complexed with PEG by ionic complex may be applicable as drug delivery carriers for increasing therapeutic efficacy of anticancer drugs.
- Published
- 2009
16. Formulation and Preparation of Sustained Release Pellet for Alfuzosin HCI Using Fluid-bed coater
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Sun-Hang Cho, Jin-Sang Na, Eun-Seok Park, Sung-Hoon Kim, Sang-Young Jeong, Sung-Joo Hwan, Hui Seo, Byung-Cheol Shin, and Yang-No Yoon
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chemistry.chemical_classification ,Chromatography ,Plasticizer ,Polymer ,Cellulose acetate ,Dibutyl sebacate ,chemistry.chemical_compound ,Membrane ,chemistry ,Pellet ,medicine ,Dissolution testing ,Alfuzosin ,medicine.drug - Abstract
Alfuzosin, an Alphal-adrenoceptor antagonist is used for the treatment of patients with voiding and in a lesser extent storage lower urinary tract symptoms (LUTS) associated to benign prostatic hyperplasia (BPH). The objective of this study was to formulate sustained release alfuzosin HCl granules and assess their formulation variables. The as a polymer, sustained release membrane, and dibutyl sebacate (DBS) as a plasticizer were used. Multi-coated alfuzosin HCl delivery systems composed of sugar sphere, various excipients, and HPMC (hydroxy propyl methyl cellulose), Cellulose Acetate were prepared by fluid-bed coater. Membrane layer were used RS PO and NE 30D. And the alfuzosin HCl coated beads were coated immediate release drug layer for initial burst. Its dissolution test was carried out compared to conventional products ( XL). The release rate of drug from coated beads was higher than that from XL in pH 6.8.
- Published
- 2008
17. Preparation and Dissolution Characteristics of Sustained Release Granules Containing Indapamide
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Hui Seo, Sun-Hang Cho, Byung Jin Kim, Sang-Young Jeong, Ji-Seon Park, Sung Joo Hwang, Sun-Hong Yuk, and Byung-Cheol Shin
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Chromatography ,Chemistry ,medicine.medical_treatment ,Indapamide ,Plasticizer ,Controlled release ,Natriuretic Effects ,chemistry.chemical_compound ,Ethyl cellulose ,medicine ,Delivery system ,Diuretic ,Dissolution ,medicine.drug - Abstract
Indapamide (4-chloro-N-(2-methyl-1-indolinyl)-3-sulfamoyl-benz-amide) is an oral antihypertensive diuretic agent indicated for the treatment of hypertensive. The diuretic and natriuretic effects are mainly due to the structure of o-chlorobenzenesulfonamide. The objective of this study was to formulate sustained release indapamide granules and assess their formulation variables. Granules were prepared by fluid bed coating method and consist of drug layer and membrane layer. The granules were coated with HPC and ethyl cellulose along with plasticizer dibuthyl sebacate. The release of indapamide depended on the type of Eudragit such as RS and NE 30 D used in the formulation controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for indapamide could be designed with satisfying drug release profile approved.
- Published
- 2008
18. Gold/chitosan/pluronic composite nanoparticles for drug delivery
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Ree Sun Kim, Keun Sang Oh, Soon Hong Yuk, Dongmin Kim, Sun Hang Cho, and Jin Ho Lee
- Subjects
Materials science ,Polymers and Plastics ,Cationic polymerization ,Nanoparticle ,General Chemistry ,Poloxamer ,Surfaces, Coatings and Films ,Chitosan ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Colloidal gold ,Drug delivery ,Polymer chemistry ,Materials Chemistry ,Particle size ,Drug carrier - Abstract
Composite nanoparticles were prepared and characterized as a sustained delivery system for paclitaxel, an anticancer drug. Gold nanoparticles were used as building blocks for constructing the composite nanoparticles. An ionic interaction between the anionic gold nanoparticles and cationic chitosan was induced to form the composite nanoparticles. Particle size analysis, field emission scanning electron microscopy, transmittance electron microscopy, and ultraviolet–visible were used to observe the formation of the composite nanoparticles. For the application of the composite nanoparticles as a drug carrier, paclitaxel was loaded into the composite nanoparticles, and the drug-release pattern was observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
- Published
- 2008
19. Enhanced Stability of Comb-Type Copolymer-Incorporated Liposomes
- Author
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Hasoo Seong, Taewon Hwang, Byung Cheol Shin, Sun Hang Cho, Suk Hyun Jung, and Hee Dong Han
- Subjects
chemistry.chemical_classification ,Acrylate ,Liposome ,Materials science ,Ethylene oxide ,Mechanical Engineering ,fungi ,Radical polymerization ,Polymer ,Methacrylate ,Hydrophobic effect ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Polymer chemistry ,Copolymer ,General Materials Science - Abstract
To enhance the stability of liposomes in systemic circulation, a number of liposomes modified with hydrophilic polymer such as poly(ethylene oxide) have been developed. In this study, the comb-type copolymer was prepared as a surface modifier of liposome and the polymer was anchored onto the lipid bi-layer via hydrophobic interaction between aliphatic chain of phospholipids and hydrophobic chain of the polymer. The comb-type copolymer was synthesized by radical polymerization of octadecyl acrylate (ODA), hydroxy-poly-(oxyethylene) methacrylate (HPOEM) and 2-Hydroxyethyl methacrylate (HEMA). The structure of the comb-type copolymer was confirmed by 1H-NMR analysis. The stability of the comb-type copolymer-incorporated liposomes (CCIL) in serum was investigated by measuring the amount of protein adsorbed onto liposomes. The CCIL showed a much lower amount of adsorbed protein than the other liposomes. Those results indicated that the stability of CCIL in serum was higher than those of the other liposomes. Thus, the comb-type copolymer composed of ODA-HPOEM-HEMA can be a promising surface modifier for enhancement of the stability of liposomes in systemic circulation.
- Published
- 2007
20. Formulation of Sustained Release Granule for Venlafaxine-HCl Using Water-Insoluble Polymer
- Author
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Sun-Hang Cho, Ji-Seon Park, Byung-Cheol Shin, Soon-Hong Yuk, Sung Joo Hwang, Jin-A Seo, and Sang-Young Jeong
- Subjects
chemistry.chemical_compound ,Chromatography ,chemistry ,Hydrochloride ,Cetyl alcohol ,Venlafaxine Hydrochloride ,Granule (cell biology) ,Plasticizer ,medicine ,Venlafaxine ,Cellulose acetate ,Controlled release ,medicine.drug - Abstract
Venlafaxine, 1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride is a novel, nontricyclic antidepressant. venlafaxine is a unique antidepressant that differs structurally from other currently available. The aim ot the study was to formulate sustained-release venlafaxine granules and assess their formulation variables. It consists of two layers, venlafaxine drug layer and sustained release coating layer and manufactured by fluidized bed process. The sustained release of drug could be increased by double-control rising various components in venlafaxine drug layer and sustained-release layer. The drug-containing granules were coated with cellulose acetate, cetyl alcohol and Eudragit RS along with plastisizer such as dibuthyl sebacate as an nano-pore former The release oi venlafaxine depended on the type of Eudragit such as RS, and RL used in the formulation of controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for venlafaxine could be designed with satisfying drug release profile approved.
- Published
- 2007
21. In Vitro Stability of Liposomes Containing Newly Synthesized Glycolipid
- Author
-
Soon-Hwa Jung, Hasoo Seong, Sun-Hang Cho, Byung-Cheol Shin, and Chung Kil Song
- Subjects
chemistry.chemical_compound ,Liposome ,Chromatography ,chemistry ,Chemistry (miscellaneous) ,Drug delivery ,PEG ratio ,Zeta potential ,Disaccharide ,Chemical Engineering (miscellaneous) ,Particle size ,Conjugate ,Protein adsorption - Abstract
Liposomes having particle size from several tens to hundreds nanometers are efficient carriers for injectable drug delivery. Enhancement of liposome stability in bloodstream has been studied because of its relatively short circulation time and fast clearance from human body by reticuloendothelial system (RES) in blood vessel. In this study, new disaccharide-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) derivatives in which lactose or sucrose as the disaccharide molecule was conjugated covalently to DSPE were synthesized. Liposomes of which surface had disaccharide molecules were prepared by incorporating the disaccharide-DSPE into liposomes as one of their lipid components. Particle size of the prepared liposomes was approximately 100 nm. The liposomes of which surface were modified with the disaccharide-DSPE showed -25 mV of zeta potential value due to the presence of hydroxyl groups on their surface, while the unmodified control liposomes showed -10 mV of zeta potential value. Loading efficiency of model drug, doxorubicin, into liposomes was about 90%. Stability of the disaccharide-modified liposomes in vitro was evaluated by monitoring the amount of protein adsorption and particle size of the liposomes in serum. Disaccharide-modified liposomes were more stable in serum than unmodified control liposomes or polyethyleneglycol (PEG)-modified liposomes due to less adsorption of serum protein and hence less increase of their particle size. The liposomes of which surface was modified with disaccharide-DSPE conjugate can be used as long-circulating carriers for drugs having high toxicity or short half-life time due to their enhanced stability in blood circulatory system.
- Published
- 2007
22. Marbofloxacin-encapsulated microparticles provide sustained drug release for treatment of veterinary diseases
- Author
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Ho Jin Kwon, Joohyeon Lee, Eun-Haeng Cho, Sun Hang Cho, Hyunggun Ji, Byung Cheol Shin, and Hee Dong Han
- Subjects
Drug ,Veterinary medicine ,Drug Liberation ,Materials science ,medicine.drug_class ,Polymers ,media_common.quotation_subject ,Antibiotics ,Bioengineering ,02 engineering and technology ,Pharmacology ,010402 general chemistry ,01 natural sciences ,Biomaterials ,chemistry.chemical_compound ,Fluoroquinolone Antibiotic ,Marbofloxacin ,medicine ,Microparticle ,media_common ,Veterinary Drugs ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,PLGA ,chemistry ,Mechanics of Materials ,Delayed-Action Preparations ,Drug delivery ,0210 nano-technology ,medicine.drug ,Fluoroquinolones - Abstract
Fluoroquinolone antibiotics with concentration-dependent killing effects and a well-established broad spectrum of activity are used commonly to treat infectious diseases caused by bacteria. However, frequent and excessive administration of these antibiotics is a serious problem, and leads to increased number of drug-resistant bacteria. Thus, there is an urgent need for novel fluoroquinolone antibiotic formulations that minimize the risk of resistance while maximizing their efficacy. In this study, we developed intramuscularly injectable polymeric microparticles (MPs) that encapsulated with marbofloxacin (MAR) and were composed of poly(D,L-lactide-co-glycolic acid) (PLGA) and poloxamer (POL). MAR-encapsulated MP (MAR-MP) had a spherical shape with particle size ranging from 80 μm to 120 μm. Drug loading efficiency varied from 55 to 85% (w/w) at increasing amount of hydrophilic agent, POL. Drug release from MAR-MP demonstrated a significant and sustained increase at increased ratios of POL to PLGA. These results indicate that MAR-MP is an improved drug delivery carrier for fluoroquinolone antibiotics, which can reduce the number of doses needed and sustain a high release rate of MAR for 2-3 days. As a novel and highly effective drug delivery platform, MAR-MP has great potential for use in a broad range of applications for the treatment of various veterinary diseases.
- Published
- 2015
23. Preparation and magnetic resonance imaging effect of polyvinylpyrrolidone-coated iron oxide nanoparticles
- Author
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Byung Kook Kwak, Sun Hang Cho, Hai Bang Lee, Soon Hong Yuk, Nak Hyun Lim, Gilson Khang, Jin A. Seo, and Ha Young Lee
- Subjects
Materials science ,Polyvinylpyrrolidone ,technology, industry, and agriculture ,Biomedical Engineering ,Iron oxide ,Analytical chemistry ,Povidone ,Infrared spectroscopy ,macromolecular substances ,Ferric Compounds ,Magnetic Resonance Imaging ,Nanostructures ,Nanoclusters ,Iron pentacarbonyl ,Biomaterials ,chemistry.chemical_compound ,Coated Materials, Biocompatible ,chemistry ,medicine ,Dimethylformamide ,Fourier transform infrared spectroscopy ,Iron oxide nanoparticles ,medicine.drug ,Nuclear chemistry - Abstract
Polyvinylpyrrolidone (PVP)-coated iron oxide nanoparticles were prepared by the thermal decomposition of Fe(CO)(5) (iron pentacarbonyl) in one step. X-ray diffraction (XRD), transmission electron microscopy (TEM), electrophoretic light scattering (ELS), infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) together with the variation of the molar ratio of PVP/Fe(CO)(5), solvent, and molecular weight of PVP, were used to characterize the PVP-coated iron oxide nanoparticles. Fifty to hundred nanometer-sized iron oxide nanoclusters with a spherical shape were formed in dimethylformamide (DMF), used as a solvent, and exhibited an enhanced stability in the aqueous media. Their magnetic properties were investigated by superconducting quantum interface device (SQUID). The in vitro cytotoxicity test revealed that the PVP-coated iron oxide nanoparticles exhibited excellent biocompatibility by MTT assay. Magnetic resonance imaging (MRI) effect was observed with the administration of PVP-coated iron oxide nanoparticles through the marginal vein of rabbit, resulting in improved detection of the liver lesions.
- Published
- 2006
24. Controlled Release of Tamsulosin from Nanopore-Forming Granules
- Author
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Seong-Mi Seo, Hai-Bang Lee, Jaehwi Lee, Hyun-Suk Lee, Sun-Hang Cho, Bong Lee, and Ha Young Lee
- Subjects
Drug ,Hydrochloride ,media_common.quotation_subject ,Granule (cell biology) ,Pharmacology ,Controlled release ,chemistry.chemical_compound ,Nanopore ,chemistry ,Oral administration ,Tamsulosin ,medicine ,Glycerol ,media_common ,medicine.drug - Abstract
Tamsulosin or a salt thereof such as its hydrochloride salt has been known to have an adrenaline receptor blocking action for urethra and prostate areas. It has been widely used as a drug which lowers the prostate pressure and improves urinary disturbance accompanied by prostate-grand enlargement, thus for the treatment of prostatic hyperplasia. To avoid dose-dependent side effects of tamsulosin upon oral administration, the development of sustained-release delivery system is essentially required, that can maintain therapeutic drug levels for a longer period of time. The aim of this study was therefore to formulate sustained-release tamsulosin granules and assess their formulation variables. We designed entric coated sustained-release tamsulosin granules for this purpose. Nano-pores in the outer controlled release membrane were needed in order to obtain initial tamsulosin release even in an acidic environment such as gastric region. In our sustained release osmotic granule system, hydroxypropylmethylcellulose in a drug-containing layer was used as a rate controller. The drug-containing granules were coated with hydroxypropylmethylcellulose phthalate (HPMCP) and Eudragit, along with glycerol triacetate as an aqueous nano-pore former. The release of tamsulosin depended heavily on the type of Eudragit such as RS, RL, NE 30D, used in the formulation of controlled release layer. These results obtained clearly suggest that the sustained-release oral delivery system for tamsulosin could be designed with satisfying drug release profile approved by the Korean Food and Drug Administration.
- Published
- 2006
25. Controlled release of bovine serum albumin using MPEG–PCL diblock copolymers as implantable protein carriers
- Author
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Sun Hang Cho, Gilson Khang, Hoon Hyun, Moon Suk Kim, Hai Bang Lee, and Kwang Su Seo
- Subjects
Materials science ,Polymers and Plastics ,biology ,Kinetics ,technology, industry, and agriculture ,Serum albumin ,macromolecular substances ,General Chemistry ,Polyethylene glycol ,musculoskeletal system ,equipment and supplies ,Controlled release ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Polymerization ,chemistry ,Polymer chemistry ,Materials Chemistry ,biology.protein ,Copolymer ,Bovine serum albumin ,Drug carrier - Abstract
MPEG–PCL diblock copolymers consisting of methoxy polyethylene glycol (MPEG) and poly(ϵ-caprolactone) (PCL) as drug carriers were synthesized by ring-opening polymerization. It is possible to control the balance between hydrophilic and hydrophobic by changing the MPEG and the ratio of ϵ-CL to MPEG. Implantable wafers were easily fabricated by the direct compression method after physical mixing of diblock copolymers and bovine serum albumin–fluorescein isothiocyanate (BSA-FITC) as a model protein drug. The BSA release from wafers prepared by MPEG–PCL diblock copolymers were higher than that from PCL with the physical blending of MPEG. The wafers prepared by a variety of MPEG–PCL diblock copolymers exhibited the controlled BSA release profiles with a dependence on MPEG–PCL diblock copolymer compositions. In addition, the changing of MPEG and PCL molecular weights within MPEG–PCL diblock copolymer controlled the initial burst of BSA. We confirmed that the diblock copolymers could be served as protein delivery carrier in implantable wafer form. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1561–1567, 2006
- Published
- 2006
26. Formation of Core/Shell Nanoparticles with a Lipid Core and Their Application as a Drug Delivery System
- Author
-
Dongmin Kim, Sun Hang Cho, Soon Hong Yuk, Kyung Eun Lee, Sung Sik Han, and Keun Sang Oh
- Subjects
Materials science ,Paclitaxel ,Polymers and Plastics ,Drug Compounding ,Nanoparticle ,Bioengineering ,Poloxamer ,Biomaterials ,chemistry.chemical_compound ,Differential scanning calorimetry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Propylene oxide ,Drug Carriers ,Calorimetry, Differential Scanning ,Ethylene oxide ,Cryoelectron Microscopy ,Lipids ,Nanostructures ,Freeze Drying ,chemistry ,Chemical engineering ,Drug delivery ,Phosphatidylcholines ,Drug carrier - Abstract
A novel preparation method for core/shell nanoparticles with a drug-loaded lipid core was designed and characterized. The lipid core is composed of lecithin and a drug, and the polymeric shell is composed of Pluronics (poly(ethylene oxide)-poly (propylene oxide)-poly(ethylene oxide) triblock copolymer, F-127). For the formation of stabilized core/shell nanoparticles, freeze-drying was performed in the presence of trehalose used as a cryoprotectant. Cryogenic transmittance electron microscopy (cryo-TEM), differential scanning calorimetry (DSC), and a particle size analyzer were used to observe the formation of the stabilized core/shell nanoparticles. For the application of the core/shell nanoparticles as a drug carrier, paclitaxel, a potent anticancer drug, was loaded into the core/shell nanoparticles, and the drug loading amount and the drug release pattern were observed.
- Published
- 2005
27. Hydrophilized poly(lactide-co-glycolide) nanoparticles with core/shell structure for protein delivery
- Author
-
Sung Kyun Han, Soon Hong Yuk, Jin Ho Lee, Dongmin Kim, and Sun Hang Cho
- Subjects
Materials science ,Ethylene oxide ,technology, industry, and agriculture ,Shell (structure) ,Ionic bonding ,Nanoparticle ,macromolecular substances ,02 engineering and technology ,Poloxamer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Copolymer ,Organic chemistry ,General Materials Science ,Propylene oxide ,Lysozyme ,0210 nano-technology - Abstract
A novel preparation method for core/shell nanoparticles with hydrophilic polymeric shell was designed and characterized. The core is composed of poly(lactide-co-glycolide) and polymeric shell is composed of pluronics (poly (ethylene oxide)-poly (propylene oxide)-poly(ethylene oxide) triblock copolymer, F-127) and hyaluronic acid (HA). The role of core is to provide the nucleus for the stable formation of hydrophilic polymeric shell by physical adsorption and that of polymeric shell is to provide the hydrophilic network for protein loading. Lysozyme, which was used as a model drug and protonated in the physiological pH, was successfully loaded into polymeric shell up to 7 wt% via ionic interaction between HA and lysozyme and the sustained release pattern was observed, which was due to the stable immobilization of lysozyme in the polymeric shell.
- Published
- 2005
28. Controlled release of paclitaxel from microemulsion containing PLGA and evaluation of anti-tumor activity in vitro and in vivo
- Author
-
Seon Hwa Kim, Gilson Khang, Bok Ki Kang, Hai Bang Lee, Se Kang Chon, Moon Suk Kim, Sang Young Jeong, and Sun Hang Cho
- Subjects
Paclitaxel ,Polymers ,Mice, Nude ,Pharmaceutical Science ,macromolecular substances ,Dosage form ,Mice ,chemistry.chemical_compound ,Drug Delivery Systems ,Microscopy, Electron, Transmission ,Polylactic Acid-Polyglycolic Acid Copolymer ,Dynamic light scattering ,In vivo ,Cell Line, Tumor ,Animals ,Humans ,Nanotechnology ,Technology, Pharmaceutical ,Organic chemistry ,Microemulsion ,Lactic Acid ,Particle Size ,Ovarian Neoplasms ,Chromatography ,Cell Death ,Chemistry ,Microchemistry ,technology, industry, and agriculture ,Drug Synergism ,Controlled release ,Molecular Weight ,PLGA ,Treatment Outcome ,Solubility ,Drug delivery ,Emulsions ,Female ,Drug Screening Assays, Antitumor ,Polyglycolic Acid - Abstract
The main objective of this study was to develop an optimal paclitaxel microemulsion prepared by self-microemulsifying drug delivery system (SMEDDS) which is a mixture of paclitaxel, tetraglycol, Cremophor ELP, and Labrafil 1944 and a paclitaxel microemulsion containing poly( d , l -lactide-co-glycolide) (PLGA) in order to offer controlled release of paclitaxel. To achieve this goal, paclitaxel and PLGA were dissolved by solubilizer like tetraglycol. There was not observed any change in molecular weight of PLGA after being solubilized by tetraglycol. The droplet size for all of the formulation of microemulsion was found in the range of 45–270 nm by dynamic light scattering (DLS). It was observed that the droplet size of microemulsion without PLGA was smaller than that of microemulsion containing PLGA by transmission electron microscopy (TEM). The droplet of microemulsion containing PLGA was almost of spherical shape with smooth surface and there was no aggregation or adhesion among droplet of microemulsion by atomic force microscopy (AFM). The release behaviour of paclitaxel from microemulsion containing PLGA having various molecular weights (8K, 33K, and 90K) exhibited a biphasic pattern characterized by a fast initial release during the first 48 h, followed by a slower and continuous release for 144 h, in contrast that the release of paclitaxel from microemulsion without PLGA was finished during 24 h. This result was identical with the result of anti-tumor activity in vitro of paclitaxel from microemulsion containing PLGA against human breast cancer cell line MCF7 and this formulation enhanced anti-tumor activity in vivo compared with microemulsion without PLGA against SKOV-3 human ovarian cancer cells bearing nude mice model.
- Published
- 2004
29. Preparation of methoxy poly(ethylene glycol)/polyester diblock copolymers and examination of the gel-to-sol transition
- Author
-
Moon Suk Kim, Gilson Khang, Hai Bang Lee, Kwang Su Seo, and Sun Hang Cho
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Polymer ,Polyester ,PLGA ,chemistry.chemical_compound ,Crystallinity ,Differential scanning calorimetry ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Ethylene glycol - Abstract
Diblock copolymers consisting of methoxy poly(ethylene glycol) (MPEG) and poly(ϵ-caprolactone) (PCL), poly(δ-valerolactone) (PVL), poly(L-lactic acid) (PLLA), or poly(lactic-co-glycolic acid) (PLGA) as biodegradable polyesters were prepared to examine the phase transition of diblock copolymer solutions. MPEG–PCL and MPEG–PVL diblock copolymers and MPEG–PLLA and MPEG–PLGA diblock copolymers were synthesized by the ring-opening polymerization of ϵ-caprolactone or δ-valerolactone in the presence of HCl · Et2O as a monomer activator at room temperature and by the ring-opening polymerization of L-lactide or a mixture of L-lactide and glycolide in the presence of stannous octoate at 130 °C, respectively. The synthesized diblock copolymers were characterized with 1H NMR, IR, and gel permeation chromatography. The phase transitions for diblock copolymer aqueous solutions of various concentrations were explored according to the temperature variation. The diblock copolymer solutions exhibited the phase transition from gel to sol with increasing temperature. As the polyester block length of the diblock copolymers increased, the gel-to-sol transition moved to a lower concentration region. The gel-to-sol transition showed a dependence on the length of the polyester block segment. According to X-ray diffraction and differential scanning calorimetry thermal studies, the gel-to-sol transition of the diblock copolymer solutions depended on their degrees of crystallinity because water could easily diffuse into amorphous polymers in comparison with polymers with a crystalline structure. The crystallinity markedly depended on both the distinct character and composition of the block segment. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5784–5793, 2004
- Published
- 2004
30. The effect of gamma irradiation on PLGA and release behavior of BCNU from PLGA wafer
- Author
-
Moon Suk Kim, Hai Bang Lee, Gang Soo Chae, Jin Soo Lee, Gilson Khang, and Sun Hang Cho
- Subjects
Carmustine ,Materials science ,Polymers and Plastics ,General Chemical Engineering ,Organic Chemistry ,Radiochemistry ,technology, industry, and agriculture ,Analytical chemistry ,macromolecular substances ,Sterilization (microbiology) ,law.invention ,Gel permeation chromatography ,PLGA ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,law ,Materials Chemistry ,medicine ,Irradiation ,Glass transition ,Electron paramagnetic resonance ,medicine.drug - Abstract
The objectives of this study were to investigate the influence of gamma irradiation for sterilization on poly(D,L-lactide-co-glycolide) (PLGA) with different molecular weight and the effect of gamma irradiation on the release behavior of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) from PLGA wafer with various irradiation doses. The effect of gamma irradiation on PLGA was evaluated by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and electron paramagnetic resonance (EPR). The weight average molecular weight (M w) and glass transition temperature (T g) of PLGA decreased after gamma irradiation. The extent ofM w reduction was dependent on irradiation dose and PLGA molecular weight. Using EPR spectroscopy, we successfully detected gamma irradiation induced free radicals in PLGA. The gamma irradiation increased the release rate of BCNU from PLGA wafer at applied irradiation doses except 2.5 Mrad of irradiation dose in this study.
- Published
- 2003
31. Local drug delivery system using biodegradable polymers
- Author
-
Moon Suk Kim, Je Kyo Jeong, Hai Bang Lee, Gilson Khang, Jeong Sik Lee, Sun Hang Cho, and John M. Rhee
- Subjects
Drug ,Materials science ,Polymers and Plastics ,Biocompatibility ,General Chemical Engineering ,media_common.quotation_subject ,Organic Chemistry ,Biological activity ,Pharmacology ,Biodegradable polymer ,PLGA ,chemistry.chemical_compound ,chemistry ,Generic drug ,Drug delivery ,Materials Chemistry ,Pharmaceutics ,media_common ,Biomedical engineering - Abstract
For last five years, we are developing the novel local drug delivery devices using biodegradable polymers, especially polylactide (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) due to its relatively good biocompatibility, easily controlled biodegradability, good processability and only FDA approved synthetic degradable polymers. The relationship between various kinds of drug [water soluble small molecule drugs : gentamicin sulfate (GS), fentanyl citrate (FC), BCNU, azidothymidine (AZT), pamidronate (ADP), 1,25(OH)2 vitamin D3, water insoluble small molecule drugs : fentanyl, ipriflavone (IP) and nifedipine, and water soluble large peptide molecule drug : nerve growth factor (NGF), and Japanese encephalitis virus (JEV)], different types of geometrical devices [microspheres (MSs), microcapsule, nanoparticle, wafers, pellet, beads, multiple-layered beads, implants, fiber, scaffolds, and films], and pharmacological activity are proposed and discussed for the application of pharmaceutics and tissue engineering. Also, local drug delivery devices proposed in this work are introduced in view of preparation method, drug release behavior, biocompatibility, pharmacological effect, and animal studies. In conclusion, we can control the drug release profiles varying with the preparation, formulation and geometrical parameters. Moreover, any types of drug were successfully applicable to achieve linear sustained release from short period (1∼3 days) to long period (over 2 months). It is very important to design a suitable formulation for the wanting period of bioactive molecules loaded in biodegradable polymers for the local delivery of drug. The drug release is affected by many factors such as hydrophilicity of drug, electric charge of drug, drug loading amount, polymer molecular weight, the monomer composition, the size of implants, the applied fabrication techniques, and so on. It is well known that the commercialization of new drug needs a lot of cost of money (average: over 10 million US dollar per one drug) and time (average: above 9 years) whereas the development of DDS and high effective generic drug might be need relatively low investment with a short time period. Also, one core technology of DDS can be applicable to many drugs for the market needs. From these reasons, the DDS research on potent generic drugs might be suitable for less risk and high return.
- Published
- 2003
32. Preparation of Solid Dosage Form containing SMEDDS of Simvastatin by Microencapsulation
- Author
-
Bok-Ki Kang, Gilson Khang, Kwang-Su Seo, Hee-Joo Kil, Bok-Young Yoon, Sun-Hang Cho, Hai-Bang Lee, and Sang-Young Jeung
- Subjects
chemistry.chemical_compound ,Chromatography ,Chemistry ,Starch ,Simvastatin ,Oil droplet ,Drug delivery ,Emulsion ,medicine ,Cationic polymerization ,Chloride ,Dosage form ,medicine.drug - Abstract
The objective of this study was to solidify the simvastatin self-microemulsifying drug delivery system (SMEDDS) and to improve the encapsulation efficiency of solidified alginate beads using sodium alginate. Typical simvastatin SMEDDS was composed of various oils, surfactants and cosurfactants. Also solidified-alginate beads was prepared by crosslinking liquid emulsion mixtures containing sodium alginate and other excipients (cetylpyridinum chloride (CP-Cl), hydroxypropyl methylcellulose, starch and so on). in solution, it has been investigated that the drug release pattern and encapsulation efficiency were varied with the ratio of cationic lipid (CP-Cl). Solidified sodium alginate beads containing simvastatin SMEDDS were redispersed into media without re-aggregation. Oil droplet size of redispersed solidified-beads in media produced smaller than the initial size. The density of beads and drug loading amount were increased with increasing cationic lipid content. These systems have advantages of storage stability and predictability of drug release rate.
- Published
- 2003
33. Preparation of 5-fluorouracil-loaded poly(L-lactide-co-glycolide) wafer and evaluation ofin vitro release behavior
- Author
-
Jin Soo Lee, Gang Soo Chae, Gilson Khang, Tae Kun An, Sun Hang Cho, and Hai Bang Lee
- Subjects
Materials science ,Polymers and Plastics ,Scanning electron microscope ,General Chemical Engineering ,Organic Chemistry ,Kinetics ,technology, industry, and agriculture ,Nanochemistry ,Nanotechnology ,macromolecular substances ,Penetration (firestop) ,PLGA ,chemistry.chemical_compound ,Crystallinity ,Differential scanning calorimetry ,chemistry ,Chemical engineering ,Materials Chemistry ,Wafer - Abstract
The controlled delivery of anticancer agents using biodegradable polymeric implant has been developed to solve the problem of penetration of blood brain barrier and severe systemic toxicity. This study was performed to prepare 5-FU-loaded poly(L-lactide-co-glycolide) (PLGA) wafer fabricated microparticles prepared by two different method and to evaluate their release profile for the application of the treatment of brain tumor. 5-FU-loaded PLGA microparticles were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), and differential scanning calorimetry (DSC). SEM observation of the 5-FU-loaded PLGA microparticles prepared by rotary solvent evaporation method showed that 5-FU was almost surrounded by PLGA and significant reduction of crystallinity of 5-FU was confirmed by XRD. In case of release profile of 5-FU from 5-FU-loaded PLGA wafer fabricated microparticles prepared by mechanical mixing, the release profile of 5-FU followed near first order release kinetics. In contrast to the above result, release profile of 5-FU from 5-FU-loaded PLGA wafer fabricated microparticles prepared by rotary solvent evaporation method followed near zero order release kinetics. These results indicate that preparation method of the 5-FU-loaded PLGA microparticles to fabricate into wafers was contributed to drug release profile.
- Published
- 2003
34. Microencapsulation of lipid nanoparticles containing lipophilic drug
- Author
-
K E Lee, Sun Hang Cho, Soon Hong Yuk, S Y Jeong, and H B Lee
- Subjects
Materials science ,Alginates ,Drug Compounding ,Administration, Oral ,Pharmaceutical Science ,Nanoparticle ,Biocompatible Materials ,Capsules ,Bioengineering ,Methylcellulose ,Polyvinyl alcohol ,Dosage form ,chemistry.chemical_compound ,Drug Delivery Systems ,Hypromellose Derivatives ,Colloid and Surface Chemistry ,Glucuronic Acid ,medicine ,Humans ,Nanotechnology ,Lovastatin ,Physical and Theoretical Chemistry ,Active ingredient ,Drug Carriers ,Anticholesteremic Agents ,Hexuronic Acids ,Organic Chemistry ,technology, industry, and agriculture ,Capsule ,Hydrogen-Ion Concentration ,Enteric coating ,Microspheres ,Biochemistry ,Chemical engineering ,chemistry ,Delayed-Action Preparations ,Emulsion ,Drug carrier ,medicine.drug - Abstract
A polymeric emulsion bead, which consists of core and capsule, was prepared. The core is composed of lipid nanoparticles containing lipophilic drug and semi-interpenetrating networks (semi-IPNs) are prepared to provide the capsule composed of sodium alginate and hydroxypropylmethyl cellulose (HPMC). The lipid nanoparticles were encapsulated into the polymeric emulsion bead with high drug loading efficiency, and lovastatin was used as a model drug. For the application as an oral drug delivery system, the enteric coating was performed with polymeric emulsion bead. The drug release pattern was controlled by the composition of capsule materials and environmental pH.
- Published
- 2003
35. Improvement of Bioavailability for Lovastatin using Self-microemulsifying Drug Delivery System
- Author
-
Gilson Khang, Young-Won Lee, Sibeum Lee, Sung Joo Hwang, Soon-Hong Yuk, Bok-Ki Kang, Sang-Young Jeung, Hai-Bang Lee, Sun-Hang Cho, and Bok-Young Yoon
- Subjects
PEG 400 ,chemistry.chemical_compound ,Chromatography ,chemistry ,Oral administration ,Drug delivery ,medicine ,Self-microemulsifying drug delivery system ,Lovastatin ,Solubility ,Polyvinyl alcohol ,medicine.drug ,Bioavailability - Abstract
A self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and ultimately bioavailability of a poorly water soluble drug, lovastatin. SMEDDS was the mixtures of oils, surfactants, and cosurfactants, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastro-intestinal (GI) tract. Various types of self-emulsifying formulations were prepared using four types of oil (Capryol 90, Lauroglycol 90, Labrafil M 1944 CS and Labrafil M 2125), two surfactants (Cremophor EL and Tween 80), and three cosurfactants (Carbitol, PEG 400 and propylene glycol). The efficiency of emulsification was studied using a laser diffraction size analyzer to determine particle size distributions of the resultant emulsions. Optimized formulations selected for bioavailability assessment were Carpryol 90 (40%), Cremophor EL (30%) and Carbitol (30%). SMEDDS containing lovastatin (20 mg and 5 mg) were compared to a conventional lovastatin tablet by the oral administration as prefilled hard gelatin capsules to fasted beagle dogs for in vivo study. The area under the serum concentration-time curve from time zero to the last measured time in serum, , was significantly greater in SMEDDS, suggesting that bioavailability increase 130% and 192% by the SMEDDS, respectively. The self-emulsifying formulations of lovastatin afforded the improvement in absolute oral bioavailability relative to previous data of lovastatin tablet formulation. These data indicate the utility of dispersed self-emulsifying formulations for the oral delivery of lovastatin and potentially other poorly absorbed drugs.
- Published
- 2002
36. Polymeric nanosphere formed from temperature-responsive polymer composed of (N,N-dimethylamino)ethyl methacrylate and ethyl acrylamide
- Author
-
Tae Bum Lee, Jung Ki Seo, Soon Hong Yuk, Seung Su Kim, Kyoung Tai No, Sun Hang Cho, and Jin Ho Lee
- Subjects
chemistry.chemical_classification ,Materials science ,Aqueous solution ,Polymers and Plastics ,Polymer ,Condensed Matter Physics ,Methacrylate ,Oligomer ,chemistry.chemical_compound ,chemistry ,Polymerization ,Dynamic light scattering ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Physical and Theoretical Chemistry ,Temperature-responsive polymer - Abstract
A nanosphere was formed from a temperature-responsive random copolymer of (N,N-dimethylamino)ethyl methacrylate (DMAEMA) and ethyl acrylamide (EAAm) without a crosslinker. When the copolymerization was performed in a water/ethanol solvent mixture (90/10 v/v %) above the lower critical-solution temperature of poly(DMAEMA-co-EAAm), the nanosphere was formed with the propagation of copolymerization. Atomic force microscopy analysis and dynamic light scattering both showed the formation of nanosphere and the size was decreased as the EAAm content increased in the copolymer. To illuminate this nanosphere formation phenomena, molecular dynamic simulations were performed with model polymer solutions. According to the analysis of the simulation trajectory, the ethyl groups of ethanol bind to the hydrophobic sites of poly(DMAEMA) or poly(DMAEMA-co-EAAm), and water molecules can bind preferentially to CO groups that are abundant on the surface of the core, which is composed of oligomer and ethanol. This may enable the polymerization to proceed within the core, which is transformed into nanosphere. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 594–600, 2001
- Published
- 2001
37. Temperature-sensitive swelling behavior of polymer gel composed of poly (N,N-dimethylaminoethyl methacrylate) and its copolymers
- Author
-
Mu Shik Jhon, Soon Hong Yuk, and Sun Hang Cho
- Subjects
chemistry.chemical_classification ,Aqueous solution ,Materials science ,Polymers and Plastics ,Organic Chemistry ,General Physics and Astronomy ,Polymer ,Methacrylate ,Lower critical solution temperature ,Polyelectrolyte ,chemistry.chemical_compound ,chemistry ,Acrylamide ,parasitic diseases ,Polymer chemistry ,Materials Chemistry ,Copolymer ,medicine ,Swelling ,medicine.symptom - Abstract
Polymer gels composed of N,N-dimethylaminoethyl methacrylate (DMAEMA) and acrylamide (AAm) (or ethyl acrylamide (EAAm)) were prepared to observe temperature-sensitive swelling behavior. The temperature dependence of equilibrium swelling of poly (DMAEMA-co-AAm) gel was in accordance with the change of the lower critical solution temperature (LCST) of poly (DMAEMA-co-AAm) aqueous solution as a function of chemical composition. However, poly (DMAEMA-co-EAAm) gel did not show the similar trend to poly (DMAEMA-co-AAm) gel. In the case of poly (DMAEMA-co-AAm), the hydrogen bond, which played an important role in controlling the LCST, was maintained with the formation of the gel network. However, the hydrogen bond in poly (DMAEMA-co-EAAm) was disrupted significantly with the formation of the gel network. This led to the difference in swelling behavior of polymer gels in response to temperature.
- Published
- 1999
38. Temperature-induced phase transition of poly(N,N-dimethylaminoethyl methacrylate-co-acrylamide)
- Author
-
Sun Hang Cho, Mu Shik Jhon, Soon Hong Yuk, and Hai Bang Lee
- Subjects
Cloud point ,Aqueous solution ,Polymers and Plastics ,Hydrogen bond ,Chemistry ,Condensed Matter Physics ,Methacrylate ,Lower critical solution temperature ,chemistry.chemical_compound ,Amide ,Acrylamide ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Physical and Theoretical Chemistry - Abstract
Copolymers of N,N-dimethylaminoethyl methacrylate (DMAEMA) and acrylamide (AAm) were prepared to demonstrate a temperature-induced phase transition. Poly DMAEMA has a lower critical solution temperature (LCST) around 50°C in water. With copolymerization of DMAEMA with AAm, the LCST shifts to the lower temperature was observed, probably due to the formation of hydrogen bonds between amide and N,N-dimethylamino groups. FT-IR studies clearly show the formation of hydrogen bonds which protect N,N-dimethylamino groups from exposure to water and result in a hydrophobic contribution to the LCST. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys, 35: 595–598, 1997
- Published
- 1997
39. A novel semi-interpenetrating networks system as an absorbent material
- Author
-
Hai Bang Lee, Sun Hang Cho, Byung Chunl Shin, and Soon Hong Yuk
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Swelling capacity ,Polyacrylic acid ,General Physics and Astronomy ,Polymer ,Biodegradation ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Materials Chemistry ,medicine ,Absorbent material ,Swelling ,medicine.symptom ,Composite material ,Sodium alginate - Abstract
A novel semi-interpenetrating networks (IPNs) system was developed in an attempt to investigate the feasibility of a polymer system as a biodegradable absorbent material. This system consisted of two chemically independent polymers. The first network consisted of sodium alginate which disintegrated by a natural erosive force. The other was a polyacrylic acid which provided a high swelling capacity to the polymer system. Swelling and DSC experiments were performed to characterize the physical properties of the model polymer system. These showed the characteristic swelling behaviors of absorbent materials. Fungi resistance tests were conducted to observe the biodegradability of the model polymer system, suggesting that the model polymer system would be attacked by a soil microorganism which would cause disintegration by a natural erosive force.
- Published
- 1996
40. pH-sensitive drug delivery system using OW emulsion
- Author
-
Soon Hong Yuk, Hai Bang Lee, and Sun Hang Cho
- Subjects
Active ingredient ,Chromatography ,Swelling capacity ,Polyacrylic acid ,Pharmaceutical Science ,Capsule ,chemistry.chemical_compound ,chemistry ,Emulsion ,Drug delivery ,medicine ,Liberation ,Swelling ,medicine.symptom - Abstract
A pH-sensitive drug delivery system has been prepared using an O W emulsion, which consists of a core and capsule. The core consists of oil and dispersed drug. A novel semi-interpenetrating networks (semi-IPNs) system has been developed to provide a capsule network which shows pH-sensitive swelling behavior. The first network consists of sodium alginate which disintegrates in the intestinal fluid. The other is a polyacrylic acid which provides pH-sensitive swelling capacity to the capsule network. The drug delivery system in this study showed a pH-sensitive drug release pattern which was due both to the diffusion of drug through the capsule network and to the escape of drug from the surface which underwent disintegration after swelling depending on the chemical composition of the capsule network and the pH of release media.
- Published
- 1995
41. Gd(III)-DOTA-modified sonosensitive liposomes for ultrasound-triggered release and MR imaging
- Author
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Byung Cheol Shin, Hasoo Seong, Seul A Lee, Suk Hyun Jung, Kyunga Na, and Sun Hang Cho
- Subjects
Drug ,Materials science ,media_common.quotation_subject ,Pharmacology ,chemistry.chemical_compound ,Materials Science(all) ,medicine ,DOTA ,General Materials Science ,Doxorubicin ,Liposome ,Ultrasound sensitivity ,Contrast agent ,Intracellular uptake ,media_common ,Nano Express ,business.industry ,Ultrasound ,Condensed Matter Physics ,chemistry ,Targeted drug delivery ,Molecular imaging ,business ,Intracellular ,medicine.drug - Abstract
Ultrasound-sensitive (sonosensitive) liposomes for tumor targeting have been studied in order to increase the antitumor efficacy of drugs and decrease the associated severe side effects. Liposomal contrast agents having Gd(III) are known as a nano-contrast agent system for the efficient and selective delivery of contrast agents into pathological sites. The objective of this study was to prepare Gd(III)-DOTA-modified sonosensitive liposomes (GdSL), which could deliver a model drug, doxorubicin (DOX), to a specific site and, at the same time, be capable of magnetic resonance (MR) imaging. The GdSL was prepared using synthesized Gd(III)-DOTA-1,2-distearoyl-sn-glycero-3-phosphoethanolamine lipid. Sonosensitivity of GdSL to 20-kHz ultrasound induced 33% to 40% of DOX release. The relaxivities (r 1) of GdSL were 6.6 to 7.8 mM−1 s−1, which were higher than that of MR-bester®. Intracellular uptake properties of GdSL were evaluated according to the intensity of ultrasound. Intracellular uptake of DOX for ultrasound-triggered GdSL was higher than that for non-ultrasound-triggered GdSL. The results of our study suggest that the paramagnetic and sonosensitive liposomes, GdSL, may provide a versatile platform for molecular imaging and targeted drug delivery.
- Published
- 2012
42. Enhancement of the targeting capabilities of the Paclitaxel-loaded pluronic nanoparticles with a glycol chitosan/heparin composite
- Author
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Sun Hang Cho, Ick Chan Kwon, Keun Sang Oh, Kwangmeyung Kim, Soon Hong Yuk, Jin Ho Lee, Sangkwon Oh, and Sang Yoon Kim
- Subjects
Male ,Paclitaxel ,Composite number ,Pharmaceutical Science ,Nanoparticle ,Polyethylene glycol ,Poloxamer ,Polyethylene Glycols ,Chitosan ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Mice ,Cell Line, Tumor ,Neoplasms ,Drug Discovery ,PEG ratio ,Spectroscopy, Fourier Transform Infrared ,Organic chemistry ,Animals ,Tissue Distribution ,chemistry.chemical_classification ,Drug Carriers ,Heparin ,technology, industry, and agriculture ,Polymer ,Antineoplastic Agents, Phytogenic ,Rats ,chemistry ,Area Under Curve ,Microscopy, Electron, Scanning ,Molecular Medicine ,Nanoparticles ,Drug carrier ,Neoplasm Transplantation ,Nuclear chemistry - Abstract
An enhancement of tumor-targeting capability was demonstrated with paclitaxel (PTX)-loaded Pluronic nanoparticles (NPs) with immobilized glycol chitosan and heparin. The PTX-loaded Pluronic NPs were prepared as described in our previous report by means of a temperature-induced phase transition in a mixture of Pluronic F-68 and liquid polyethylene glycol (PEG; molecular weight: 400) containing PTX. The liquid PEG is used as the solubilizer of PTX, and Pluronic F-68 is the polymer that encapsulates the PTX. The glycol chitosan and heparin were immobilized on the surface of the Pluronic NPs in an aqueous medium, and a powdery form of the glycol chitosan/heparin immobilized Pluronic NPs (composite NPs) was obtained by freeze-drying. Field emission scanning electron microscopy and a particle size analyzer were used to observe the morphology and size distribution of the prepared NPs. To apply the composite NPs as a delivery system for the model anticancer drug PTX, the release pattern and pharmacokinetic parameters were observed, and the tumor growth was monitored by injecting the composite NPs into the tail veins of tumor-bearing mice. An enhancement of tumor-targeting capability of NPs was verified by using noninvasive live animal imaging technology to observe the time-dependent excretion profile, the in vivo biodistribution, circulation time, and the tumor-targeting capability of composite NPs.
- Published
- 2011
43. Tumor accumulation and antitumor efficacy of docetaxel-loaded core-shell-corona micelles with shell-specific redox-responsive cross-links
- Author
-
Sang Cheon Lee, Sun Hang Cho, Sang Uk Lee, Kwangmeyung Kim, Ick Chan Kwon, Kyung Hyun Min, Ahn Na Koo, Hong Jae Lee, and Seo Young Jeong
- Subjects
Diagnostic Imaging ,Time Factors ,Biophysics ,Bioengineering ,Antineoplastic Agents ,Docetaxel ,Micelle ,Polyethylene Glycols ,Biomaterials ,chemistry.chemical_compound ,Mice ,In vivo ,Cell Line, Tumor ,Neoplasms ,PEG ratio ,In Situ Nick-End Labeling ,Animals ,Humans ,Polylysine ,Tissue Distribution ,Disulfides ,Particle Size ,Micelles ,chemistry.chemical_classification ,Chromatography ,Aqueous two-phase system ,Polymer ,Glutathione ,Permeation ,Carbocyanines ,Cross-Linking Reagents ,Treatment Outcome ,chemistry ,Mechanics of Materials ,Ceramics and Composites ,Taxoids ,Peptides ,Ethylene glycol ,Oxidation-Reduction - Abstract
A robust core-shell-corona micelle bearing redox-responsive shell-specific cross-links was evaluated as a carrier of docetaxel (DTX) for cancer therapy. The polymer micelles of poly(ethylene glycol)-b-poly(L-lysine)-b-poly(L-phenylalanine) (PEG-PLys-PPhe) in the aqueous phase provided the three distinct functional domains: the PEG outer corona for prolonged circulation, the PLys middle shell for disulfide cross-linking, and the PPhe inner core for DTX loading. The shell cross-linking was performed by the reaction of disulfide-containing cross-linkers with Lys moieties in the middle shells. The shell cross-linking did not change the micelle size or the spherical morphology. The shell cross-linked micelles exhibited enhanced serum stability. The DTX release from the DTX-loaded disulfide cross-linked micelles (DTX-SSCLM) was facilitated by increasing the concentration of glutathione (GSH). At an intracellular GSH level, DTX release was facilitated due to the reductive cleavage of the disulfide cross-links in the shell domains. The in vivo tissue distribution and tumor accumulation of the DTX-SSCLM that were labeled with a near-infrared fluorescence (NIRF) dye, Cy5.5, were monitored in MDA-MB231 tumor-bearing mice. Non-invasive real-time optical imaging results indicated that the DTX-SSCLM exhibited enhanced tumor specificity due to the prolonged stable circulation in blood and the enhanced permeation and retention (EPR) effect compared with the DTX-loaded non-cross-linked micelles (DTX-NCLM). The DTX-SSCLM exhibited enhanced therapeutic efficacy in tumor-bearing mice compared with free DTX and DTX-NCLM. The domain-specific shell cross-linking that is described in this work may serve as a useful guidance for enhancing the antitumor therapeutic efficacy of various polymer micelles and nano-aggregates.
- Published
- 2011
44. Synthesis and characterization of PVP-coated large core iron oxide nanoparticles as an MRI contrast agent
- Author
-
Shouheng Sun, Jin Hyung Lee, Shan X. Wang, Xiaoyuan Chen, Xiaoying Wang, Bing Wu, Robert Sinclair, Jin Xie, Dwight G. Nishimura, Ai Leen Koh, Sang Hoon Lee, Sandip Biswal, Sun Hang Cho, Ha-Young Lee, and Chenjie Xu
- Subjects
Prussian blue ,Materials science ,Polyvinylpyrrolidone ,Mechanical Engineering ,MRI contrast agent ,Iron oxide ,technology, industry, and agriculture ,Nanoparticle ,Bioengineering ,General Chemistry ,macromolecular substances ,Article ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Dynamic light scattering ,chemistry ,Mechanics of Materials ,Transmission electron microscopy ,medicine ,General Materials Science ,Electrical and Electronic Engineering ,Iron oxide nanoparticles ,Nuclear chemistry ,medicine.drug - Abstract
The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI) contrast agent. The PVP-IO nanoparticles were synthesized by a thermal decomposition method and characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and a superconducting quantum interface device (SQUID). The core size of the particles is about 8-10 nm and the overall size is around 20-30 nm. The measured r(2) (reciprocal of T(2) relaxation time) and r2∗ (reciprocal of T2∗ relaxation time) are 141.2 and 338.1 (s mM)(-1), respectively. The particles are highly soluble and stable in various buffers and in serum. The macrophage uptake of PVP-IO is comparable to that of Feridex as measured by a Prussian blue iron stain and phantom study. The signal intensity of a rabbit liver was effectively reduced after intravenous administration of PVP-IO. Therefore PVP-IO nanoparticles are potentially useful for T(2)-weighted MR imaging.
- Published
- 2011
45. Core/Shell nanoparticles with lecithin lipid cores for protein delivery
- Author
-
Hyun Suk Lee, Hyoung Mo Koo, Kyung Eun Lee, Ree Sun Kim, Sun Hang Cho, Keun Sang Oh, Sung Kyun Han, Sung Sik Han, and Soon Hong Yuk
- Subjects
Vascular Endothelial Growth Factor A ,Drug Carriers ,Materials science ,Polymers and Plastics ,Ethylene oxide ,Shell (structure) ,Nanoparticle ,Bioengineering ,Poloxamer ,Nanostructures ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Phosphatidylcholine ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Phosphatidylcholines ,Animals ,Humans ,Muramidase ,Propylene oxide ,Drug carrier - Abstract
Core/shell nanoparticles with lipid core, were prepared and characterized as a sustained delivery system for protein. The lipid core is composed of protein-loaded lecithin and the polymeric shell is composed of Pluronics (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, F-127). Based on the preparation method in the previous report by us, the freeze-drying of protein-loaded lecithin was performed in the F-127 aqueous solution containing trehalose used as a cryoprotectant to form stabilized core/shell nanoparticles. Cryo-TEM (transmittance electron microscopy) and a particle size analyzer were used to observe the formation of stabilized core/shell nanoparticles. For the application of core/shell nanoparticles as a protein drug carrier, lysozyme and vascular endothelial growth factor (VEGF) were loaded into the core/shell nanoparticles by electrostatic interaction, and the drug release pattern was observed by manipulating the polymeric shell.
- Published
- 2006
46. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents
- Author
-
Gilson Khang, Ha Young Lee, Byung Kook Kwak, Hye Won Jee, Sun Hang Cho, and Sung Mi Seo
- Subjects
Gadolinium ,Biomedical Engineering ,Pharmaceutical Science ,chemistry.chemical_element ,Bioengineering ,Conjugated system ,Microscopy, Atomic Force ,Micelle ,chemistry.chemical_compound ,Nuclear magnetic resonance ,Micelles ,Pharmacology ,Aspartic Acid ,Molecular Structure ,Ligand ,Organic Chemistry ,Pentetic Acid ,Fluorescence ,Magnetic Resonance Imaging ,chemistry ,Polymerization ,Proton NMR ,Peptides ,Ethylene glycol ,Biotechnology - Abstract
Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI−mPEG-C16−(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.
- Published
- 2006
47. Hydrophilized poly(lactide-co-glycolide) nanospheres with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer
- Author
-
Sun Hang Cho, B. K. Kim, Daehwan Kim, and Soon Hong Yuk
- Subjects
Materials science ,Paclitaxel ,Polymers ,Drug Compounding ,Oxide ,Pharmaceutical Science ,Excipient ,Bioengineering ,Antineoplastic Agents ,macromolecular substances ,Polyethylene Glycols ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Microscopy, Electron, Transmission ,Polylactic Acid-Polyglycolic Acid Copolymer ,Polymer chemistry ,medicine ,Copolymer ,Humans ,Propylene oxide ,Lactic Acid ,Physical and Theoretical Chemistry ,Drug Carriers ,Ethylene oxide ,Organic Chemistry ,technology, industry, and agriculture ,Poloxamer ,Nanostructures ,PLGA ,Biodegradation, Environmental ,chemistry ,Chemical engineering ,Drug delivery ,Hydrophobic and Hydrophilic Interactions ,Polyglycolic Acid ,medicine.drug - Abstract
A novel method for preparing the PLGA nanospheres with hydrophilic surface has been designed and characterized. Because of good solubility of tetraglycol in water, PLGA (poly(lactide-co-glycolide)) nanospheres were formed by spraying the PLGA/tetraglycol solution into water. The size of PLGA nanospheres was manipulated by changing the concentration of PLGA/tetraglycol solution. Based on the hydrophobic interaction between PLGA and poly(propylene oxide) domain of F-127 (one of Pluronics, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer, F-127-coated PLGA nanospheres was prepared to enhance the stability of PLGA nanospheres in the aqueous media. For the application as a drug delivery vehicle, it was characterized by measuring the loading amount, the encapsulation efficiency and the release pattern of drug. Paclitaxel used as a potent anti-cancer drug was selected as a model drug.
- Published
- 2005
48. Preparation of poly(ethylene glycol)-block-poly(caprolactone) copolymers and their applications as thermo-sensitive materials
- Author
-
Kwang Su Seo, Moon Suk Kim, Gilson Khang, Hai Bang Lee, and Sun Hang Cho
- Subjects
Ethylene Oxide ,Materials science ,Hot Temperature ,Magnetic Resonance Spectroscopy ,Polymers ,Injections, Subcutaneous ,Polyesters ,Biomedical Engineering ,Biocompatible Materials ,macromolecular substances ,Polyethylene glycol ,Polyethylene Glycols ,Biomaterials ,chemistry.chemical_compound ,Polymer chemistry ,Copolymer ,Animals ,chemistry.chemical_classification ,Drug Carriers ,technology, industry, and agriculture ,Chain transfer ,Polymer ,musculoskeletal system ,Rats ,Solutions ,chemistry ,Polymerization ,Polycaprolactone ,Indicators and Reagents ,Hydrochloric Acid ,Caprolactone ,Ethylene glycol ,Gels - Abstract
The polymerization of ϵ-caprolactone (ϵ-CL) was initiated by the terminal alcohol of methoxy poly(ethylene glycol) (MPEG) as an initiator via activated ring-opening polymerization in the presence of HCl · Et2O as a monomer activator. The molecular weights of the poly(ϵ-caprolactone) (PCL) in MPEG–PCL diblock copolymers controlled with the feed ratio of ϵ-CL to MPEG. The polymerization was preceded by living fashion with no termination or chain transfer. This polymerization procedure offered MPEG–PCL diblock copolymers with well-defined structures. The gel-to-sol transitions of MPEG–PCL diblock copolymer solutions were also examined. The diblock copolymers synthesized with various MPEG and PCL lengths were dissolved in water at 80°C in various concentrations. The polymer solutions formed gel at room temperature. The formed gel became fluids again by increasing the temperature. The gel-to-sol transition showed strong dependence on the length of the MPEG and PCL diblock segments. When the polymer solution was injected into rat, it became a gel at body temperature. The formed gel maintained for 1 month. We confirmed that MPEG–PCL diblock copolymers with well-defined structures served as new thermo-sensitive biomaterials. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 154–158, 2004
- Published
- 2004
49. Evaluation of in vitro and in vivo antitumor activity of BCNU-loaded PLGA wafer against 9L gliosarcoma
- Author
-
Gang Soo Chae, Tae Kun An, Gilson Khang, Je Kyo Jeong, Hai Bang Lee, Jin Soo Lee, and Sun Hang Cho
- Subjects
Male ,medicine.medical_specialty ,Cell Survival ,Polymers ,Drug Evaluation, Preclinical ,Pharmaceutical Science ,Antineoplastic Agents ,Gliosarcoma ,chemistry.chemical_compound ,Polylactic Acid-Polyglycolic Acid Copolymer ,In vivo ,Cell Line, Tumor ,medicine ,Animals ,Wafer ,Lactic Acid ,Cytotoxicity ,Antitumor activity ,Chemistry ,technology, industry, and agriculture ,General Medicine ,9l gliosarcoma ,Controlled release ,Carmustine ,In vitro ,Rats, Inbred F344 ,Surgery ,Rats ,PLGA ,Cancer research ,Polyglycolic Acid ,Biotechnology - Abstract
The purpose of the present study was to develop implantable BCNU-loaded poly(D,L-lactide-co-glycolide) (PLGA) wafer for the controlled release of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and to evaluate its in vitro and in vivo antitumor activity. The release rate of BCNU from PLGA wafer increased with the increase of BCNU amount loaded and the release was continued until 7 days. In vitro and in vivo antitumor activity of BCNU-loaded PLGA wafer was investigated using in vitro cytotoxicity against 9L gliosarcoma cells and a subcutaneous (s.c.) solid tumor model of 9L gliosarcoma, respectively. The wafers containing BCNU showed more effective cytotoxicity than BCNU powder due to its short half-life and inhibited the proliferation of 9L gliosarcoma cells. BCNU-loaded PLGA wafer delayed the growth of the tumors significantly and increasing the dose of BCNU in the wafer resulted in a substantial regression of the tumor. These results of antitumor activity of BCNU-loaded PLGA wafer demonstrate the feasibility of the wafers for clinical application.
- Published
- 2003
50. Effect of lactide/glycolide monomers on release behaviors of gentamicin sulfate-loaded PLGA discs
- Author
-
Gilson Khang, Moon Suk Kim, Jong Min Kim, Je Young Yoo, Yong Sik Kim, Hai Bang Lee, and Sun Hang Cho
- Subjects
Lactide ,Stereochemistry ,Polymers ,Chemistry, Pharmaceutical ,Pharmaceutical Science ,Microbial Sensitivity Tests ,Hydrogen-Ion Concentration ,Controlled release ,Dosage form ,Anti-Bacterial Agents ,chemistry.chemical_compound ,Gentamicin Sulfate ,PLGA ,Monomer ,Drug Delivery Systems ,chemistry ,Polylactic Acid-Polyglycolic Acid Copolymer ,Delayed-Action Preparations ,Liberation ,Lactic Acid ,Gentamicins ,Polyglycolic Acid ,Antibacterial agent ,Nuclear chemistry - Abstract
In order to develop the desirable drug release patterns such as no lag time and exact zero-order release rate, gentamicin sulfate (GS)-loaded poly(D,L-lactide-co-glycolide) (PLGA) discs containing lactide monomer (LM) or glycolide monomer (GM) were prepared. LM or GM was applied for the controlling drug release pattern due to its non-toxic and biodegradable nature. Water absorption, mass loss, pH change, and morphology of discs were examined to study the effect of LM or GM addition. GS release showed near zero-order profile in the GS-loaded polymeric discs prepared in the presence of LM or GM (10%). The channel of GS-loaded PLGA containing LM or GM was formed by the dissolution of LM or GM. Water uptake of disc increased till 21 days from the beginning of the test. The pH variations of media declined in the same manner with the result of mass loss. The antibiosis of GS was also confirmed by bacterial inhibition zone test using the prepared polymeric discs. From these results, we expected that the polymeric discs containing LM or GM would be a good dosage form as a topically implantable device which can get rid of lag period from PLGA matrix.
- Published
- 2003
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