Search

Here, a novel kind of composite scaffold was fabricated by loading vascular endothelial growth factor (VEGF) and gastrodin liposome (GAS-LP) into electrospun silk fibroin/graphene oxide(SF/GO)nanofibrous and silk fibroin sponge-filled, respectively. Our results demonstrated that VEGF and GAS exhibited different release patterns in vitro which VEGF showed rapid release rate in the first few days while GAS was released slowly and continuously as encapsulated in liposomes. The scaffolds realized the combination of intraneural vascularization drugs and electrical stimulation effectively, leading to enhanced growth of RSC96 cells. Furthermore, the scaffolds could protect RSC96 cells in an inflammatory environment. [ABSTRACT FROM AUTHOR]

Nanoscale metal–organic framework (nMOF) based nano drug delivery systems show great potential in the biomedical field. In this work, a drug delivery system combined with chemotherapy and phototherapy (DOX/ICG@UiO-66-TK-PEG-F3 or simplified as DI@UiO-TPF3) was designed for the targeted therapy of tumors. The chemotherapeutic drug doxorubicin (DOX) and the photothermal therapeutic agent indocyanine green (ICG) were loaded onto the pH-sensitive UiO-66-NH2 carrier core by physical adsorption, and the surface of UiO-66-NH2 was modified by the multifunctional polymer TK-PEG-F3 to improve the stability and targeting of the drug-loaded core. Characterizations show that the drug delivery system DI@UiO-TPF3 was successfully prepared with an excellent drug loading rate (21.6%) and photothermal conversion efficiency (32.92%). DI@UiO-TPF3 not only shows the ability to stimulate a response to release drugs, but also achieves the synergistic anti-tumor effects of chemotherapy and photothermal/photodynamic therapy (PTT/PDT), which was confirmed by in vitro evaluation. In addition, cell experiments have confirmed that DI@UiO-TPF3 connected with F3 peptide can selectively bind to the nucleolin overexpressed on the surface of tumor cells and reduce the toxicity to normal cells. Therefore, DI@UiO-UTPF3 provided a feasible strategy for constructing a targeted drug delivery platform integrating chemotherapy and phototherapy. [ABSTRACT FROM AUTHOR]

Peripheral nerve injury (PNI) has become one of the common clinical diseases. How to promote the regeneration and function recovery of the damaged peripheral nerve has been the focus of attention in the medical field. Evidence suggests that the longitudinal filling of oriented fibers in nerve guide conduit (NGC) is especially beneficial to the repair of long gap PNI. In this study, polypyrrole (PPy) nanospheres (PNSs) were prepared by the soft-templating method, and mixed with poly (lactic acid) (PLA) to prepare conductive PNSs/PLA NGC, and the optimal ratio of PNSs was 4.5%. PLA and vascular endothelial growth factor (VEGF) as shell, chitosan (CS) and paeoniflorin (PF) as core, oriented coaxial nanofibers were obtained and then filled into PNSs/PLA NGC. The composite NGC has excellent mechanical properties, electrical conductivity, hydrophilic properties, and degradation properties. Besides, the successive release of VEGF and PF can play a synergistic role in promoting nerve regeneration. In vitro experiments showed that the composite NGC was nontoxic and suitable for the adhesion and proliferation of nerve cells. In addition, PNSs combined with electrical stimulation (ES) can significantly promote the differentiation and proliferation of nerve cells, which is conducive to nerve regeneration. These positive results indicate that the composite NGC is a promising candidate in the repair of long gap PNI. [ABSTRACT FROM AUTHOR]

Conductive polymers show great promise because of their electrical property based on bioelectricity in vivo. In order to search electro-activity materials which insure abduction of tissue, we synthesized conductive nerve conduits with poly-dl-lactic-acid (PDLLA) and tetra-aniline (TA). Preparation technology of TA was optimized, and the properties of the conduit were studied. RSC96 cell were used to investigate the toxicity and electrical stimulation effect. SD rats were used to assess biocompatibility in vivo. The results showed that the reaction ratio of 1:1, the reaction time of 2 h and the HCl concentration of 2 mol/L were the optimum conditions for synthesis of TA. The influence of TA content on the mechanical properties, hydrophilicity, conductivity and microstructure of the nerve conduit was evaluated. Cell and histocompatibility study showed PDLLA/TA possessed good biocompatibility. These results showed it had application values in tissue projects. [ABSTRACT FROM AUTHOR]

In this study, a novel drug delivery system (HMSNs-SS-HA) based on hollow mesoporous silica nanoparticles (HMSNs) was developed for delivering anticancer drugs (e.g., doxorubicin (DOX)) to targeted tumour cells by using disulfide bonds as redox-sensitive linkers and hyaluronic acid (HA) molecules as both capping and targeting agents. Well-dispersed HMSNs were synthesized with a dimension of around 100 nm. Detailed physical characterization further demonstrated that HMSNs-SS-HA has been successfully constructed. The in vitro drug release experiments displayed the enzyme and redox dual-responsive and sustained drug release properties of DOX loaded HMSNs-SS-HA. Additionally, a series of biological evaluations indicated that these DOX loaded HMSNs-SS-HA could accurately target murine mammary carcinoma (4T1) cells to induce cell apoptosis in vitro and suppress tumour growth in vivo. These results demonstrated that DOX loaded HMSNs-SS-HA was suitable as a potential and efficient drug delivery nanosystem for cancer therapy. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) modified with hyaluronic acid (HA) and Arg-gly-asp peptide (RGD) was designed as a dual-receptor targeting drug delivery system to enhance the specificity and efficiency of anticancer drug delivery. Firstly, GO-HA-RGD conjugate was characterized to reveal its structure and morphology. Whereafter, doxorubicin (Dox) as a model drug was loaded on GO-HA-RGD carrier, which displayed a high loading rate (72.9%, GO:Dox (w/w) = 1:1), pH-response and sustained drug release behavior. Cytotoxicity experiments showed that GO-HA-RGD possessed excellent biocompatibility towards SKOV-3 and HOSEpiC cells. Additionally, the GO-HA-RGD/Dox had a stronger cytotoxicity for SKOV-3 cells than either GO-HA/Dox (single receptor) or GO/Dox (no receptor). Moreover, celluar uptake studies illustrated that GO-HA-RGD conjugate could be effectively taken up by SKOV-3 cells via a synergic effect of CD44-HA and integrin-RGD mediated endocytosis. Hence, GO-HA-RGD nanocarrier is able to be a promising platform for targeted cancer therapeutic. [ABSTRACT FROM AUTHOR]

The usage of hollow nerve conduits shows inferior recovery effect on the repair of peripheral nerve defects. In this study, a biocompatible and biodegradable pH-induced injectable chitosan–hyaluronic acid hydrogel for nerve growth factor encapsulation and sustained release was developed as the fillers in the lumen of hollow nerve conduit to reform its microenvironment for peripheral nerve regeneration. The physicochemical properties of hydrogel were characterized by gelation time, Fourier transform infrared spectroscopy, scanning electron microscopy, compressive modulus, porosity, swelling ratio, and in vitro degradation. The in vitro nerve growth factor release profiles and cell evaluation were also investigated. The results show that the structure of chitosan–hyaluronic acid hydrogel is composed of interconnected channels with a controllable pore diameter ranging from 20 to 100 µm. The hydrogel can be degraded more than 70% within 8 weeks in vitro and is available for nerve growth factor sustained release. The chitosan–hyaluronic acid/nerve growth factor hydrogel is non-toxic and suitable for adhesion and proliferation of nerve cells and capable of maintaining nerve growth factor activity. Therefore, it could be a promising intraluminal filler of nerve conduits for peripheral nerve regeneration in neural tissue engineering. [ABSTRACT FROM AUTHOR]

The use of methotrexate (MTX), an anticancer drug for the treatment of hematologic malignancies, has been limited in the clinical application due to its poor water solubility, high clearance rate, and lack of target specificity. To solve these problems, O, N-carboxymethyl chitosan-dipeptide-MTX conjugates have been synthesized and characterized by fourier transform infrared radiation spectroscopy and proton nuclear magnetic resonance (H NMR). All polymeric conjugates showed satisfactory water solubility. The results of the study revealed that drug release and toxicity were affected by employing polymeric conjugation strategy and dipeptide spacers [glycylglycine (Gly-Gly), glycyl- l-phenylalanine (Gly-Phe), glycyl- l-tyrosine (Gly-Tyr)]. It has been found that drugs could be effectively loaded and released when polymeric prodrugs were combined with a dipeptide spacer. In conclusion, O, N-CMCS-dipeptide-MTX polymeric prodrugs could potentially be used as responsive drug delivery systems. [ABSTRACT FROM AUTHOR]

Prodrug development is an important strategy for improving tumor cell targeting and the selectivity of anticancer drugs. In this study, poly(ethylene glycol) and melphalan, an anticancer drug, were linked to the backbone of hyaluronic acid via amide bonds using carbodiimide chemistry to synthesize a poly(ethylene glycol)–hyaluronic acid–melphalan prodrug. The physicochemical properties of the prodrug were characterized by Fourier transform infrared, proton nuclear magnetic resonance, ultraviolet–visible spectroscopy, and dynamic light scattering and transmission electron microscopy. The in vitro drug release profiles and the corresponding in vitro cell evaluation of the prodrug were investigated. The poly(ethylene glycol)–hyaluronic acid–melphalan prodrug was successfully synthesized and self-assembled into 116.4-nm nanoparticles. The release profiles demonstrated that controlled release of the prodrug could be achieved with a sensitive property involving both pH and enzymatic degradation. The poly(ethylene glycol)–hyaluronic acid–melphalan prodrug was more effectively transferred into the ovarian tumor cell (SKOV3) than into human ovarian fibroblast (HOF) cells. It also had a higher inhibition effect on SKOV3 and a lower inhibition effect on HOF than melphalan. This poly(ethylene glycol)–hyaluronic acid–melphalan prodrug, with its controlled release properties and selectivity, is a promising drug delivery system for cancer therapy. [ABSTRACT FROM PUBLISHER]

Abstract: The Fe3O4 ferrofluids have been prepared using sodium alginate (Na–AL) as a stabilizing agent. The alginate can prevent the aggregation of magnetic nanoparticles and hence contributed to higher stability for the ferrofluids. Furthermore, the alginate component in the ferrofluids was crosslinked by Ca2+ to produce magnetic microspheres. The swelling behavior of magnetic microspheres showed a pH-dependence, and hence determined the drug release process under various pH conditions. The presence of the Fe3O4 nanoparticles made the magnetic microspheres swell more easily. Meanwhile, the strong ability to absorb the drug for the incorporated Fe3O4 nanoparticles decreased the release rate and hence was more favorable to the sustaining release of drug. Except for the controlled delivery and release of drug, the alginate-based ferrofluids and magnetic microspheres in this work might also show a great potential for other biomedical and biotechnological applications, such as, magnetic targeting, magnetic separation and magnetic resonance imaging. [ABSTRACT FROM AUTHOR]

The article discusses a study which prepared a thermoformable starch-graft-polycaprolactone (PCL) biocomposite by initiating ring-open polymerization of caprolactone monomer into starch under microwave irradiation. The study reported that the resultant biocomposites were injection-molded, and the sheets and their structure and properties were investigated using X-ray diffraction, contact angle measurement and others. It also suggested the potential of the biocomposites as a biomedical material.

The article presents a study which filled a polycaprolactone (PCL) matrix with a biocompatible polysaccharide-grafted PLC, chitosan-g-PCL (CS-g-PCL) to improve the performance of PCL-based materials. The findings revealed that the rigidity of the CS chains and the increasing crystallinity enhanced the strength of the materials. The study also found that the interfacial structure and improved miscibility between CS and PCL matrix enhanced the elongation of the composite materials.

Biopolymeric hollow nanospheres with stabilized structure have been prepared by self-assembly of amphiphatic photocrosslinkable carboxymethyl chitosans in a water medium into hollow nanocapsules and subsequent in situphoto-crosslinking of the photoreactive functional groups in the shells of the nanocapsules. [ABSTRACT FROM AUTHOR]

Surgical resection of osteosarcoma is always accompanied by residual metastasis of tumor cells and bone tissue defects. In this work, a novel kind of gelatin/polylactic acid (PLA) coaxial fiber membrane with a shell layer containing doxorubicin-loaded hydroxyapatite (DOX@nHAp) nanoparticles and a core layer containing Icariin (ICA) was developed for antitumor and bone enhancement at the defect site. Physical evaluation displayed that the composite membrane provided moderate hydrophilicity, enhanced tensile strength (Dry: 2–3 MPa, wet: 1–2 MPa) and elasticity (70–100 %), as well as increased specific surface area and pore volume (19.39 m2/g and 0.16 cm3/g). In SBF, DOX@nHAp in the fibers promoted biomineralization on the fiber surface. In in vitro evaluation, approximately 80 % of DOX had a short-term release during the first 8 days, followed by long-term release behavior of ICA for up to 40 days. CCK-8 results confirmed that the membrane could actively support MC3T3-E1 cells proliferation and was conductive to high alkaline phosphatase expression, while the viability of MG-63 cells was effectively inhibited to 50 %. Thus, the dual-loaded fibrous membrane with a coaxial structure and nHAp is a promising system for anticancer and defects reconstruction after osteosarcoma surgery. [Display omitted] [ABSTRACT FROM AUTHOR]

• A novel drug delivery system was designed based on hollow mesoporous silica nanoparticles. • Hyaluronic acid was served as gatekeeper as well as targeted agent. • The system could target murine mammary carcinoma (4T1) cells. • The system could combine chemotherapy and photodynamic therapy. In this work, a pH-responsive and tumor targeted multifunctional drug delivery system (RB-DOX@HMSNs-N = C-HA) was designed to realize chemo-photodynamic combination therapy. Hollow mesoporous silica nanoparticles (HMSNs) was served as the host material to encapsulate doxorubicin (DOX) and photosensitizer rose bengal (RB). Hyaluronic acid (HA) was modified on the surface of HMSNs via pH-sensitive Schiff base bonds as gatekeeper as well as targeted agent. Characterization results indicated the successful preparation of HMSNs-N = C-HA with appropriate diameter of 170 nm around and the nanocarriers displayed superior drug loading capacity (15.30 % for DOX and 12.78 % for RB). Notably, the results of in vitro drug release experiments confirmed that the system possessed good pH-sensitivity, which made it possible to release cargoes in slight acid tumor micro-environments. Significantly, the in vitro cell uptake and cytotoxicity assay results fully proved that RB-DOX@HMSNs-N = C-HA could precisely target murine mammary carcinoma (4T1) cells and effectively inhibit tumor cells viability with chemo-photodynamic synergistic therapy. Overall, our work (RB-DOX@HMSNs-N = C-HA) provides an efficient approach for the development of chemo-photodynamic combination therapy. [ABSTRACT FROM AUTHOR]

• Hollow mesoporous silica nanoparticles based drug delivery system was constructed. • The prepared system had pH sensitivity and high drug loading capacity. • The delivery system could knockdown P-gp protein expression on HCT-8/TAX cells. • The drug-loaded system could combat multidrug resistance cancer effectively. A nanocarrier system of methoxypolyethylene glycol amine (mPEG-NH 2) functionalized polydopamine (PDA) coated hollow mesoporous silica nanoparticles (HMSNs-PDA-PEG) was developed with pH-responsive, which combined doxorubicin hydrochloride (DOX) and quercetin (QUR) to reverse multidrug resistance (MDR) and improved anticancer effects on taxol (TAX) and DOX double resistant human colorectal cancer cell line HCT-8 (HCT-8/TAX cells). Well-dispersed nanoparticles (HMSNs-PDA-PEG) were prepared with a dimension of around 170 nm. The surface morphology and chemical properties of HMSNs-PDA-PEG were also successfully characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, Fourier transform infrared spectroscopy (FT-IR) and dynamic light scattering (DLS). Drug release experiments results indicated that DOX and QUR (QD) loaded nanoparticles (HMSNs-PDA-PEG@QD) had similar release kinetic profiles of each drug, which all exhibited highly sensitive to pH value due to the surface PDA coating. Additionally, the HCT-8 cells or HCT-8/TAX cells were employed to assess the cellular uptake and cytotoxicity of various drug-free or drug-loaded HMSNs samples. Meanwhile, a series of biological evaluations demonstrated that the HMSNs-PDA-PEG@QD exhibited remarkable ability to overcome MDR compared with free DOX and HMSNs-PDA-PEG@DOX. Taken together, these results revealed that HMSNs-PDA-PEG@QD was suitable as a prospective and efficient drug delivery nanosystem for overcoming multidrug resistance. [ABSTRACT FROM AUTHOR]