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Abstract: Hyperbranched amphiphilic polymer PG6–PLA–PEG was synthesized through grafting hydrophobic poly(d,l-lactide) (PLA) segments and hydrophilic poly(ethylene glycol) (PEG) blocks to hydrophilic hyperbranched polyglycerol core (PG6), subsequently. To achieve cell targeting property, folic acid (FA) was further incorporated to the hyperbranched polymer to obtain PG6–PLA–PEG–FA. The polymers were characterized by 1H NMR, UV–vis spectroscopy and combined size-exclusion chromatography and multiangle laser light scattering (SEC-MALLS) analysis. Due to the amphiphilicity, PG6–PLA–PEG and PG6–PLA–PEG–FA could self-assemble to form nanoparticles in aqueous solutions. Antineoplastic drug, paclitaxel (PTX), was encapsulated into the nanoparticles. The nanoparticles were observed by transmission electron microscopy (TEM). The targeting property of PG6–PLA–PEG–FA was evaluated in vitro. The results showed that the PTX loaded PG6–PLA–PEG–FA nanoparticles exhibited enhanced inhibition on folate receptor positive tumor cells due to the folate mediated targeting. [Copyright &y& Elsevier]

Abstract: Hyperbranched polymers, PG6–PEI25k and PG6–PEI800, were synthesized through grafting branched polyethylenimines (PEIs) with molecular weights of 25kDa and 800Da to a polyglycerol core (PG6), respectively. The structure of the polymers was characterized by 1H NMR and FTIR. Through agarose gel electrophoresis retardation assay, PG6–PEI25k and PG6–PEI800 were demonstrated to have capability for DNA binding. PG6–PEI/DNA complexes with different weight ratios were characterized by TEM and particle size analysis. The activity of PG6–PEIs to mediate transfection of reporter plasmids pEGFP-C1 and pGL3-Luc was evaluated on 293T and HeLa cell lines. PG6–PEI25k and PG6–PEI800 showed enhanced levels in transgene expression and decreased cytotoxicities as compared with PEI25k and PEI800, respectively. The results indicated potential applications of PG6–PEIs for efficient gene delivery. [Copyright &y& Elsevier]

Graphical abstract Aptamer-functionalized albumin-based nanoparticles can effectively deliver the drug to targeted tumor cells to achieve enhanced therapeutic efficiency. Highlights • A tumor targeting aptamer-functionalized albumin-based drug delivery system was prepared. • A hydrophobic drug was employed to trigger the self-assembly of bovine serum albumin. • Aptamer-functionalized nanoparticles show enhanced tumor cell inhibitory efficacy. • Aptamer-functionalized nanoparticles can induce cell apoptosis more effectively. • Aptamer-functionalized nanoparticles can prevent tumor progression more effciently. Abstract Proteins have been extensively explored as versatile nanocarriers for drug delivery due to their complete biocompatibility, ease of surface modification, and lack of toxicity and immunogenicity. In this study, a facile strategy was used to construct aptamer-functionalized albumin-based nanoparticles for effective drug delivery and targeted cancer therapy. A hydrophobic drug, doxorubicin (DOX) was employed to trigger the self-assembly of bovine serum albumin (BSA) to from stable nanoparticles via hydrophobic interaction, and then a tumor targeting aptamer AS1411 was incorporated to the surface of DOX loaded BSA. Due to the specific recognition between AS1411 and its receptor over-expressed on tumor cells, the aptamer-modified nanoparticles show higher cellular uptake and stronger cell inhibitory efficacy against cancerous MCF-7 cells as compared with the nanoparticles without aptamer modification. In addition, DOX loaded aptamer-functionalized nanoparticles can induce more significant down-regulation of Bcl-2 and PCNA as well as up-regulation of pRB, PARP and Bax in MCF-7 cells compared with unmodified nanoparticles, indicating the aptamer modification can induce cell apoptosis more effectively. Besides, aptamer-modified nanoparticles exhibit a significantly improved capability in up-regulating p16, p21 and E-cadherin, and down-regulating EpCAM, vimentin, Snail, MMP-9, CD44 and CD133, implying the favorable effects of drug delivery on the prevention of tumor progression and metastasis. [ABSTRACT FROM AUTHOR]

To effectively reverse multiple drug resistance (MDR) in tumor treatments, a functional nano-sized drug delivery system with active targeting function and pH sensitivity was prepared for the co-delivery of multiple drug resistance inhibitors. Buthionine sulfoximine (BSO) to inhibit GSH synthesis and celecoxib (CXB) to down-regulate P-gp expression were co-loaded in polymer/inorganic hybrid nanoparticles to form buthionine sulfoximine/celecoxib@biotin-heparin/heparin/calcium carbonate/calcium phosphate nanoparticles (BSO/CXB@BNP). To investigate the reversal of MDR, the drug resistant cells (MCF-7/ADR) were pretreated by the dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) followed by the treatment of doxorubicin (DOX) loaded nanoparticles (DOX@BNP). The dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) exhibited greatly enhanced efficiency in down-regulation of GSH and P-gp since BSO and CXB had combined effects on the reduction of GSH and P-gp in drug resistant tumor cells. As a result, BSO/CXB@BNP exhibited a significantly improved capability in reversal of MDR compared with mono-inhibitor loaded nanoparticles (CXB@BNP and BSO@BNP). As compared with free drug resistance inhibitors, delivery of drug resistance inhibitors by functional nanocarriers could obviously improve the therapeutic efficiency due to enhanced cellular uptake and increased intracellular drug accumulation. The study on immunostimulatory effects of different treatments showed that BSO/CXB@BNP treatment resulted in the lowest concentration of interleukin 10, a cytokine related to tumor development. These results suggest the nanoparticulate drug delivery platform developed in this study has promising applications in multiple drug delivery to overcome drug resistance in tumor treatments. [ABSTRACT FROM AUTHOR]

A facile strategy to prepare nano-sized drug carriers for co-delivery of multiple types of drugs in combination chemotherapy was developed. Inorganic/organic hybrid alginate/CaCO 3 nanoparticles were prepared by co-precipitation in an aqueous solution under very mild conditions. A hydrophilic drug (doxorubicin hydrochloride, DOX) and a hydrophobic drug (paclitaxel, PTX) were co-encapsulated in the hybrid nanoparticles. For comparison, PTX loaded nanoparticles and DOX loaded nanoparticles were also prepared. The measurement based on dynamic light scattering indicated all nanoparticles had a mean size less than 200 nm with a relatively narrow size distribution. The morphology of the nanoparticles was observed by TEM. The in vitro drug release study showed that the release of DOX and PTX from the dual drug loaded nanoparticles could be effectively sustained. The tumor cell inhibitory effect of the drug loaded nanoparticles was evaluated in HeLa cells and MCF-7/ADR cells. The dual drug loaded nanoparticles exhibited significantly enhanced cell uptake and nuclear localization as compared with the single drug loaded nanoparticles. As a result, the dual drug loaded nanoparticles had a significantly enhanced cell inhibitory effect, especially for drug resistant tumor cells. These results indicated that alginate/CaCO 3 hybrid nanoparticles have promising applications for the co-delivery of drugs with different physicochemical properties in combination chemotherapy to overcome multidrug resistance. [ABSTRACT FROM AUTHOR]

Highlights: [•] A facile strategy to modify CaCO3 based gene delivery systems was developed. [•] CaCO3/CaP/DNA nanoparticles were prepared by a facile co-precipitation method. [•] CaCO3/CaP/DNA nanoparticles exhibited significantly improved delivery efficiency. [ABSTRACT FROM AUTHOR]

Abstract: A facile method to prepare inorganic/organic hybrid heparin/CaCO3/CaP nanoparticles for drug delivery was developed. The heparin/CaCO3/CaP nanoparticles were prepared by the co-precipitation of Ca2+ ions with carbonate and phosphate ions in the presence of heparin. The effects of ion concentrations on the particle size and properties of the nanoparticles were investigated. The dynamic light scattering (DLS) particle size analysis and scanning electron microscopy (SEM) observation showed that the mean size of the hybrid nanoparticles could be controlled at less than 50nm in the dried state through adjusting the concentrations of the inorganic ions. Fourier transform infrared (FTIR) spectroscopy indicated that the crystallization of CaCO3 could be suppressed with the presence of phosphate ions in the co-precipitation system. X-ray photoelectron spectroscopy (XPS) showed that the heparin content in the surface layer of heparin/CaCO3/CaP hybrid nanoparticles decreased with the increasing ion concentrations during the nanoparticle preparation. The drug loading and release properties of the hybrid nanoparticles with different sizes and different compositions were studied. The in vitro cellular cytotoxicity indicated that blank hybrid nanoparticles had good biocompatibility, whereas doxorubicin hydrochloride (DOX) loaded nanoparticles exhibited a strong cell inhibition effect, indicating that the heparin/CaCO3/CaP hybrid nanoparticles could be promising carriers for drug delivery. [Copyright &y& Elsevier]

Abstract: Chitosan-cyclodextrin nanospheres were prepared by in situ formation through Michael addition between N-maleated chitosan (NMC) and per-6-thio-β-cyclodextrin sodium salt in an aqueous medium. This facile preparation method did not involve any organic solvent and surfactant. Through adjusting the preparation conditions, the nanospheres with a relatively narrow size distribution could be obtained. The obtained nanospheres were characterized by TEM and particle size analyzer. Doxorubicin hydrochloride (DOX·HCl), a water soluble anticancer drug, was loaded in the nanospheres with a high encapsulation efficiency. The in vitro drug release showed that the release of DOX·HCl from the nanospheres could be effectively sustained. The cytotoxicity evaluation showed the drug loaded nanospheres exhibited efficient inhibition on HeLa cells. [Copyright &y& Elsevier]

Abstract: In this study, with the aim of designing an ideal anticancer drug carrier, we synthesized novel amphiphilic graft copolymers, P(Glu-alt-PEG)-graft-PCLA, based on poly(ethylene glycol) (PEG) segments and glutamic acid (Glu) units as the hydrophilic main chain, and poly(ɛ-caprolactone-co-lactide) (PCLA) as hydrophobic branches. The chemical structure of the copolymers was characterized by 1H MNR and FT-IR. The self-assembly of the copolymers to form micelles was studied by TEM, DLS and fluorescence spectroscopy. In vitro doxorubicin controlled release studies demonstrated that these graft copolymer micelles had high drug loading capacity and good controlled released properties, demonstrating their potential as a novel anticancer drug carrier. The drug loaded graft copolymer micelles exhibited efficient inhibition of HeLa cells in in vitro studies. [Copyright &y& Elsevier]

Abstract: Composite microparticle drug delivery systems based on chitosan, alginate and pectin with improved pH sensitivity were developed for oral delivery of protein drugs, using bovine serum albumin (BSA) as a model drug. The composite drug-loaded microparticles with a mean particle size less than 200μm were prepared by a convenient shredding method. Since the microparticles were formed by tripolyphosphate cross-linking, electrostatic complexation by alginate and/or pectin, as well as ionotropic gelation with calcium ions, the microparticles exhibited an improved pH-sensitive drug release property. The in vitro drug release behaviors of the microparticles were studied in simulated gastric (pH 1.2 and pH 5.0), intestinal (pH 7.4) and colonic (pH 6.0 and pH 6.8 with enzyme) media. For the composite microparticles with suitable compositions, the releases of BSA at pH 1.2 and pH 5.0 could be effectively sustained, while the releases at pH 7.4, pH 6.8 and pH 6.0 increased significantly, especially in the presence of pectinase. These results clearly suggested that the microparticles had potential for site-specific protein drug delivery through oral administration. [Copyright &y& Elsevier]

Abstract: In order to investigate the influence of the continuous alkylamide sequence having pH sensitive unit on the temperature sensitivity of poly(N-isopropylacrylamide) (PNIPAAm)-based hydrogel, a monomer, N-(2-(dimethylamino) ethyl)-methacrylamide (DMAEMA), having an ethylamide group as well as an aliphatic tertiary amino group, was designed and synthesized. Hydrogels based on NIPAAm and DMAEMA were prepared via free radical polymerization. The resulted P(NIPAAm-co-DMAEMA) hydrogels were characterized in terms of maximum swelling ratio, swelling kinetics, temperature response kinetics, and effect of pH. The data obtained show that the novel hydrogels have the strong desire to respond to external temperature and pH stimuli. Importantly, because the P(NIPAAm-co-DMAEMA) hydrogels have the continuous alkylamide sequence containing isopropylamide pendant groups from PNIPAAm and ethylamide pendant groups from PDMAEMA, the incorporation of DMAEMA moiety not only provides the pH sensitivity, but also maintains the thermal properties of P(NIPAAm-co-DMAEMA) hydrogels, even as the molar percentage of DMAEMA moiety reaches 14mol%. [Copyright &y& Elsevier]

Abstract: Biodegradable amphiphilic graft copolymers with different compositions were synthesized by grafting poly(l-lactide) (PLLA) sequences onto a water-soluble poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA) backbone. The critical micelle concentration (CMC) of the graft polymers was determined by fluorescence probe technique. Using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, the graft polymers were proved to have low cytotoxicity. Based on the specific physicochemical property of the graft copolymers, submicron sized microsphere drug delivery systems were prepared by a very convenient “ultrasonic dispersion method”, which did not involve toxic organic solvents. The drug-loaded microspheres had a regular spherical shape with a narrow size distribution. A hydrophobic drug, prednisone acetate, was encapsulated into polymeric microspheres and the in vitro drug release was studied. [Copyright &y& Elsevier]

Abstract: To investigate the temperature sensitive mechanism and develop temperature sensitive materials, a novel poly(N-isopropyl-3-butenamide) (PNIPBAm) hydrogel was designed and synthesized. The maximum swelling ratio, temperature dependence of swelling ratio and deswelling/reswelling kinetics of the resulted PNIPBAm hydrogel were characterized. The data obtained exhibited that the temperature sensitivity of the PNIPBAm hydrogel depended on the amount of crosslinker, i.e. the temperature sensitivity decreased with the increasing content of crosslinker. This novel temperature sensitive hydrogel would have the potential applications in bioengineering and biotechnology fields. [Copyright &y& Elsevier]