POLYMER DEGRADATION AND STABILITY
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2012
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IF 2.769
Ying Wan,Junchao Huang,Jun Zhang,Dengke Yin,Zijie Zheng,Chunyan Liao,Shaofa Sun
Multi-channel chitosan–polycaprolactone (CH–PCL)/collagen conduits were fabricated for potential applications in long-gap peripheral nerve repair. CH–PCLs with various PCL percentages changing from around 30 to 45 wt% were used for the fabrication of conduits, and the collagen content in the conduits was controlled at about 8 wt% or less in order to ensure the required mechanical strength and degradation rate of the resulting conduits. The porosity and average channel diameter of the conduits with a dimension of around 5 mm in outer diameter and 30 mm in length were optimized as around 80% and 200 μm, respectively. Swelling index, compressive load, deformation recovery and bending stiffness of the conduits were measured, respectively. In vitro degradation measurements was conducted in phosphate buffer saline, and results revealed that the effect of collagen content on the degradation rate of the conduits was not significant until the degradation time reached around 6 weeks. After being implanted into rabbits for various durations, the degradation of the conduits appeared to be strongly dependent on the collagen content in addition to the dependence on the degradation time. After 10-week in vivo degradation, some conduits that contained 6 wt% or less content of collagen still showed shape integrity and required compressive mechanical properties , suggesting that the degradation rate of the conduits can be effectively regulated by the collagen content while the required properties for the conduits would be well maintained.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
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2013
·Vol. 24
·期 9
·2093-2100
·
IF 2.141
Guo Rui,Chen Lili,Cai Shushan,Liu Zonghua,Zhu Yi,Xue Wei,Zhang Yuanming
Polysaccharides based polyelectrolyte complex nanoparticles (PCNs) intended for use in the delivery of macromolecules were prepared by the self-assembly of deoxycholic acid hydrophobically modified chitosan (CS-DCA) core and then coated with sodium alginate (ALG) shell. The CS-DCA capable of forming nano-sized self-aggregates in medium was prepared by the grafting of DCA to CS. In order to increase the stability of nanoparticles and prevent burst release of drug in bloodstream, polyanionic ALG was coated on the surface of positively charged CS-DCA nanoparticles to form PCNs. Dynamic light scattering results revealed that the mean diameter of the PCNs was about 330 nm, larger than that of uncoated nanoparticles (~150 nm). The zeta potential was big enough to keep the stability of PCNs (−28 mV); no size change was found even upon 1 month storage. Bovine serum albumin could be easily incorporated into the PCNs with encapsulation efficiency (>44 %) and keep a sustained manner without burst release when exposed to PBS (pH 7.4) at 37 °C. These results suggested that PCNs may be a promising drug carrier for a prolonged and sustained delivery in the bloodstream.
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CARBOHYDRATE POLYMERS
·
2013
·
IF 3.479
Bo Lu,Dan Huang,Hua Zheng,Zhijun Huang,Peihu Xu,Haixing Xu,Yihua Yin,Xia Liu,Dan Li,Xueqiong Zhang
A series of melphalan-O-carboxymethyl chitosan (Mel-OCM-chitosan) conjugates with different spacers were prepared and structurally characterized. All conjugates showed satisfactory water-solubility (160-217 times of Mel solubility). In vitro drug release behaviors by both chemical and enzymatic hydrolysis were investigated. The prodrugs released Mel rapidly within papain and lysosomal enzymes of about 40–75%, while released only about 4–5% in buffer and plasma, which suggested that the conjugates have good plasma stability and the hydrolysis in both papain and lysosomes occurs mostly via enzymolysis. It was found that the spacers have important effect on the drug content, water solubility, drug release properties and cytotoxicity of Mel-OCM-chitosan conjugates. Cytotoxicity studies by MTT assay demonstrated that these conjugates had 52–70% of cytotoxicity against RPMI8226 cells in vitro as compared with free Mel, indicating the conjugates did not lose anti-cancer activity of Mel. Overall these studies indicated Mel-OCM-chitosan conjugates as potential prodrugs for cancer treatment.
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CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2013
·
IF 0.769
Yuan-Yuan JIANG,Kun WANG,Chong-Zheng XU,Xiao-Di YANG,Hui-Hui LI
In this work, the glassy carbon electrode modified by alizarin (AR) hybridized with graphene (CRG) and chitosan (CS) was prepared. The AR/CRG-CS electrode exhibited a pair of well-defined reversible redox peaks in 0.1 M phosphate buffer solution (PBS, pH 7.4) with the oxidation peak at −0.573 V and the reduction peak at −0.652 V. It exhibited a two-proton and two-electron redox process and a fast heterogeneous electron transfer rate with the rate constant ( K s ) of 1.69 s −1 using the cyclic voltammetry. Based on the characteristics of alizarin with the decreased current and negative potential shift after binding with human telomere DNA, a sensitive, simple, reliable and stable electrochemical method for the detection of human telomere DNA using the AR/CRG-CS electrode was developed. The electrochemical response showed a linear relationship with DNA concentration in the range of 8.0 × 10 −8 −1.4 × 10 −5 M ( R = 0.9995) with the linear regression equation as Δ I pc (μA) = 8.4860 + 0.5366 C (μmol) and the detection limit ( S/N ) as 2.0 × 10 −8 M.
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JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A
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2013
·Vol. 102
·期 3
·801-807
·
IF 2.834
Ke Jiang,Ziming Wang,Quanyin Du,Jiang Yu,Aimin Wang,Yan Xiong
The post-operative outcome of flexor tendon healing remains limited by flexor tendon adhesion that reduces joint range of motion. Despite improvement in different methods, peritendinous adhesion formation continues to present a formidable challenge. Recent studies showed that transforming growth factor-β3 (TGF-β3) may be the key factor to reducing adhesion formation in skin or tendon. In this study, we designed a novel type of tissue engineering synovial sheath containing TGF-β3, to prevent flexor tendon adhesion. First, to achieve a stable release of TGF-β3, chitosan microspheres, prepared by crosslinking-emulsion, were used for the delivery of TGF-β3. Second, a three-dimensional chitosan scaffold was prepared by lyophilization, and TGF-β3 microspheres were carefully introduced into the scaffold. Then, synovial cells were cultured and then seeded into the TGF-β3 loaded scaffold to produce TGF-β3 controlled-released tissue engineering synovial sheath. Tests clearly demonstrated that the scaffold has good structure and compatibility with cells. These results expand the feasibility of combinative strategies of controlled protein release and tissue-engineered synovial sheath formation. Application of this scaffold to tendon repair sites may help to prevent adhesion of tendon healing. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 801–807, 2014.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2014
·
IF 3.096
Weiqiang Huo,Weixin Zhang,Wei Wang,Xiaohua Zhou
Two types of microcapsules (MCs) were prepared by the emulsion cross-linking method, where biguanidino chitosan (BGCS)and O -carboxymethyl chitosan ( O -CMCS) served as the wall materials, and the antibacterial agent 2,4-diamino-6-(2-pyridyl)-1,3,5-triazine (PyTNH) served as a model water-soluble drug. The physicochemical performance of the MCs and their drug release behavior were investigated by Fourier transform infrared spectroscopy, thermogravimetric analysis/derivative thermogravimetric analysis, scanning electron microscopy, and swelling and in vitro drug release studies of the two MCs with unmodified chitosan-MCs (CS-MCs) used as the control. The results indicated that the degree of cross-linking, encapsulation efficiency, and thermal stability of the shell wall of the BGCS-microcapsules (BGCS-MCs) were much higher than those of the control and the O -CMCS-microcapsules (CMCS-MCs), owing to the reduction of steric hindrance and development of the conjugation effect in the cross-linking process. Studies on the swelling and in vitro drug-release behavior revealed a sustained release effect of the BGCS-MCs. Moreover, the CMCS-MCs were found to exhibit a pH-dependent drug release behavior, which can be attributed to the successive formation of H-bonds and repulsive forces with the change in the pH of the medium. Based on these results, the swelling-release models and the drug release kinetics of BGCS-MCs and CMCS-MCs are proposed.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2014
·
IF 3.552
Hao Guo,Dongying Yuan,Guoqi Fu
Surface protein imprinting over nano- or micron-sized substrates is an effective approach for improving the biomacromolecule mass transfer and rebinding capacity. For achieving high recognition performance, it is necessary to introduce certain functional groups onto the surface of the support materials which can interact with the template protein. Herein, we report a surface protein imprinting approach using a new kind of core–shell magnetic chitosan submicrospheres as the supports. The surface of these magnetic chitosan particles is tethered with uncross-linked chitosan chains, hence bearing plenty of amino and hydroxyl groups, where a large amount of functional ligands can be readily coupled for capturing of the protein template. With lysozyme as a model print protein, the magnetic supports were functionalized with maleic acid and then coated with imprinted polymer layers. The resulting imprinted microspheres show significantly selective rebinding for lysozyme. In particular, they exhibit a specific rebinding capacity about three times higher than achieved with our previous lysozyme-imprinted particles synthesized in similar way but with maleic acid modified silica nanoparticles as the supports. This can be attributed to the much higher template binding capacity to the modified magnetic chitosan submicrospheres. Also, the resultant imprinted particles can be easily collected by a magnet. Therefore, such kind of chitosan submicrospheres may be a versatile carrier for constructing high-capacity and magnetically recyclable surface protein-imprinted particles.
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CARBOHYDRATE POLYMERS
·
2014
·
IF 3.916
Wenjiao Ge,Dong Li,Meiwan Chen,Xiaohui Wang,Shijie Liu,Runcang Sun
β-Carotene (β-C) is a well-established natural antioxidant agent, but its poor water-solubility, low chemical stability and low bioavailability limit its application in food, pharmaceuticals and cosmetics industries. Thus it is critical to develop an efficient method to improve the water solubility and stability of β-C. In this research, amphiphilic chitosan-graft-poly (lactide) (CS-g-PLA) copolymer was synthesized via a homogeneous ring-opening polymerization (ROP) in ionic liquid. The obtained CS-g-PLA copolymer was able to self-assemble into about 14 nm micelles in water at low concentration, and β-C loaded micelles (β-C/M) had low β-C degradation after 15 days. The antioxidant properties of the β-C/M were investigated by the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method and ferric reducing antioxidant power (FRAP) method, respectively. Significantly improved antioxidant activity was observed for β-C/M in compare with free β-C. The aqueous dispersion of β-C/M has potential to be applied in the field of functional food and cosmetics.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 132
·期 22
·
IF 1.768
Yong Liu,Jieyi Liang,Shoulian Wei,Ling Liu,Miaochan Liao
The purpose of this study was to fabricate and evaluate nanoparticles based on β-conglycinin (7S) and chitosan (CS) to deliver 5-fluorouracil (5-FU). The nanoparticles were prepared with a self-assembly method. Turbidity measurements performed at 600 nm were used to investigate the formation of the nanoparticles as a function of the pH, 7S-to-CS mass ratio, and total concentration of 7S and CS. The optimum conditions for the preparation of the nanoparticles were a pH of 5.5, a 7S-to-CS mass ratio of 4 : 1, and total concentration of 7S and CS of 9 mg/mL. Under these conditions, the nanoparticles in solution had a high turbidity and good stability. Fourier transform infrared spectroscopy revealed that the nanoparticles were formed mainly through electrostatic interactions between the amine groups ( NH 3 + ) of CS and the carboxyl groups ( COO − ) of 7S. Scanning electron microscopy micrographs and dynamic light scattering analysis showed that the nanoparticles had an approximately spherical morphology with a smooth surface, and the mean particle size was about 120 nm with a narrow size distribution. The release of 5-FU showed an initial burst release followed by a sustained release, and the release was pH-dependent. The release mechanism of 5-FU was Fickian diffusion according to the Ritger–Peppas model. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 41963.
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SURFACE & COATINGS TECHNOLOGY
·
2014
·
IF 2.199
Linlin Huang,Jinhong Yi,Qiang Gao,Xudong Wang,Yashao Chen,Peng Liu
To improve the corrosion resistance and cytocompatibility of magnesium alloy (Mg alloy), an anticorrosive and bioactive composite coating was triumphantly prepared on Mg alloy surface. First, Mg alloy substrates were treated by cathodic plasma electrolytic deposition (CPED). Then, bioactive carboxymethyl chitosan (CMCS) was covalently immobilized on CPED-treated Mg alloy via polydopamine as intermediate layer. X-ray photoelectron spectroscopy and scanning electronic microscopy were employed to detect the change of chemical composition and surface morphology of Mg alloy substrate at various stages of surface modification. Results of water contact angle measurement showed that the hydrophilicity of the surface has improved significantly after surface modification. Potentiodynamic polarization data and hydrogen evolution test demonstrated that corrosion resistance of modified Mg alloy significantly increased compared with that of pristine sample. Cytotoxicity test and cell morphology analysis confirmed that adhesion and proliferation of osteoblasts on CMCS-modified Mg alloy surface were improved remarkably. The approach presented here would be attractive for surface modification of biomaterials.
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RSC Advances
·
2015
·Vol. 5
·期 128
·105901-105907
·
IF 3.84
Guan-Hai Wang,Hui-Kang Yang,Yi Zhao,Da-Wei Zhang,Li-Ming Zhang,Jian-Tao Lin
In this work, novel biodegradable cationic micelles were prepared based on poly-(N-ε-carbobenzyloxy-L-lysine) (PZLL) and chitosan (CS) by click reaction, and applied for co-delivery of doxorubicin (DOX) and p53 plasmid. The structure of the copolymer was characterized by 1H NMR and FTIR. The loading amount of DOX in the micelles was 12.8%. Fluorescence spectra confirmed that DOX interacted via π–π stacking with micelles when DOX was encapsulated into the micelles. In particular, its complexation with plasmid DNA was investigated using agarose gel electrophoresis, flow cytometry, zeta potential, and particle size analyses as well as transmission electron microscopy observations. The results showed that the copolymers have a strong pDNA condensation ability and provide protection of pDNA against deoxyribonuclease I degradation. CS-g-PZLL/DOX/p53 nanoparticles showed good gene transfection efficiency in vitro. Fluorescence images and flow cytometry tests revealed that p53 and DOX could be efficiently transported into Hela tumor cells simultaneously, and the optimum N/P ratio for p53 transfection was 20/1. For co-delivery analysis, the obtained CS-g-PZLL/DOX/p53 complexes showed a better inhibitory effect on Hela tumor cells than DOX or p53 used singly.
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CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Zixuan Pang,Qianyun Li,Kun Liu,Xiaopei Wu,Haixing Xu,Zhenbing Chen,Honglian Dai
The healing of diabetic wounds is significantly impeded due to severe oxidative stress and hindered angiogenesis, presenting a major challenge to clinical treatment. In this context, we introduces a novel hydrogel dressing strategy that uniquely combines α-lipoic acid-modified chitosan (LAMC) and melanin nanoparticles (MNPs). This innovative hydrogel, LAMC@MNPs, is formulated to gel under ultraviolet (UV) light without the need for a photoinitiator , simplifying the preparation process and potentially enhancing safety. Our experimental results demonstrate that the LAMC@MNPs hydrogel not only exhibits superior skin adhesion, with an average strength of 56.59 ± 3.16 KPa, but also effectively alleviates oxidative stress and accelerates vascular regeneration and wound healing . This is achieved by promoting cell migration and scavenging free radicals , addressing the critical barriers in diabetic wound care. The combination of these materials and their functional benefits presents a promising new approach to diabetic wound treatment.
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