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Li Z.-T.,Wuhan University | Guo J.,Wuhan University | Zhang J.-S.,Wuhan Institute of Technology | Zhao Y.-P.,Wuhan University | And 3 more authors.
Carbohydrate Polymers

A novel chitosan-graft-polyethylenimine (CHI-g-PEI) copolymer with biocleavable disulfide linkages between chitosan chains and PEI grafts was synthesized, characterized, and examined as a potential nonviral gene vector. The chemical structure of the obtained product was characterized by 1H NMR, FTIR and Raman spectroscopy, respectively. Agarose gel retardation assay, dynamic light scattering, and scanning electron microscopy experiments revealed that CHI-g-PEI had a good ability of condensing plasmid DNA into spherical nanoparticles in the size range of 200-300 nm. In the imitative physiological environment the polymer/pDNA complexes are relatively stable, meanwhile, an efficient release of pDNA was detected in the presence of 25 mM DTT, mimicking the intracellular reductive environment. These results show that the bioreducible CHI-g-PEI copolymer, thus obtained, can be used as a promising nonviral gene carrier due to its excellent properties. Source

Zhu Z.,Wuhan University | Zhu Z.,Hubei Key Laboratory on Organic and Polymeric Optoelectronic Materials | Xu L.,Wuhan University | Zhou X.,Wuhan University | And 5 more authors.
Chemical Communications

Controllable turn off/on fluorescent sensors for Hg2+ detection were developed by designing different label-free DNA sequences and using the minor groove dye of DAPI. These assays exhibit high sensitivity and selectivity, with the detection limits of 5 nM and 1.5 nM for turn off and turn on sensors, respectively. © 2011 The Royal Society of Chemistry. Source

Huang Y.,Wuhan University | Zhang L.,Wuhan University | Yang J.,Wuhan University | Yang J.,Key Laboratory of Biomedical Polymers | And 3 more authors.
Macromolecular Materials and Engineering

Cytocompatible nanocomposite films are prepared by blending α-chitin whiskers and cellulose solution in NaOH/urea. Structure and properties of the chitin/cellulose composite films are characterized by FT-IR, XRD, 13C NMR, SEM, UV-Vis, TGA, and tensile tests. The results reveal that the chitin whiskers are dispersed homogeneously, leading to good miscibility and properties of the chitin/cellulose composite films. By varying the chitin whisker content, the tensile strength and elastic modulus of the films can be controlled. HeLa and T293 cells are seeded onto the surfaces of the nanocomposite films, showing that the composite films were nontoxic to both cell types and that the addition of chitin whiskers promotes cell adhesion and proliferation. Chitin whisker/cellulose nanocomposite films exhibit good miscibility and favorable mechanical properties. The addition of chitin whiskers imrproves the mechanical properties and cytocompatibility of the cellulose matrix significantly. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Zhang L.,Key Laboratory of Biomedical Polymers | Hu C.-H.,Key Laboratory of Biomedical Polymers | Cheng S.-X.,Key Laboratory of Biomedical Polymers | Zhuo R.-X.,Key Laboratory of Biomedical Polymers
Colloids and Surfaces B: Biointerfaces

Hyperbranched polymers, PG6-PEI25k and PG6-PEI800, were synthesized through grafting branched polyethylenimines (PEIs) with molecular weights of 25 kDa and 800 Da 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. © 2009 Elsevier B.V. All rights reserved. Source

Su W.,Key Laboratory of Biomedical Polymers | Feng J.,Key Laboratory of Biomedical Polymers | Wang H.-F.,Key Laboratory of Biomedical Polymers | Zhang X.-Z.,Key Laboratory of Biomedical Polymers | Zhuo R.-X.,Key Laboratory of Biomedical Polymers

The primary aim of this paper is to explore the influence of the number of CH2 groups per -(CH2)nOCOO- repeat unit (Numc) on the properties of poly(alkylene carbonate)s. A series of poly(alkylene carbonate)s with different Numc, including PTMC (Numc = 3), PTeMC (Numc = 4), PPMC (Numc = 5), PHMC (Numc = 6) and PDMC (Numc = 10) were investigated for that purpose by DSC and XRD techniques. The method of Sn(Oct)2-catalyzed ring-opening polymerization was developed to prepare poly(pentamethylene carbonate)s (PPMC), which presented a controllable feature. Regarding crystallization rate and Tm of poly(alkylene carbonate)s, an interesting odd-even effect was first reported related to the Numc. The order of crystallizing ability of poly(alkylene carbonate) was: PTMC (Numc = 3) < PPMC(Numc = 5) < PTeMC (Numc = 4) < PHMC (Numc = 6) < PDMC (Numc = 10). Poly(alkylene carbonate)s characterized with even Numc appeared to readily crystallize relative to that with odd Numc. © 2010 Elsevier Ltd. All rights reserved. Source

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