31 July 2014, Volume 45 Issue 14-生物

    

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  Formation and characterization of composite coatings containing hydroxyapatite on magnesium alloy AZ91D by micro-arc oxidation coupled with sol-gel technology

  Cheng-Hao Liang

  . 2014, 45(14-生物): 1-0.

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  Bioactive composite coatings containing hydroxyapatite (HA) on magnesium alloy AZ91D were prepared successfully by micro-arc oxidation (MAO) coupled with sol-gel technology. The morphologies of the composite coatings formed by MAO treatment at 0.5 A cm-2 current density coupled with sol-gel treatment appeared to be much denser and smoother than the coatings produced at 1.0 A cm-2. The Ca/P molar ratio (1.70) of the composite coatings produced at 0.5 A cm-2 is slightly higher than the ratio of the sol prepared (1.67), due to the CO32- substitute PO43- groups in apatite lattice according to the FTIR test. Moreover, electrochemical tests illustrated that the composite coatings (0.5 A cm-2) had lower corrosion current density and higher corrosion resistance than the composite coatings at 1.0 A cm-2. Immersion tests have been performed showing an enhanced bioactivity and apatite-formed ability. Consequently, combining the MAO and sol-gel treatments provides a promising candidate for further investigating.
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  Pharmacokinetic study of chitosan-based in situ forming hydrogel

  . 2014, 45(14-生物): 2-0.

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  Chitosan based in situ forming hydrogel（ChG） is composed of chitosan derivative and alginate derivative which is designed as a hemostasis in vivo. It is of critical importance to study the pharmacokinetics and biodegradation mechanism of this new biomaterial. Here, we present the pharmacokinetics mode of fluorescein isothiocyanate-labeled ChG (FITC-ChG) in rats. It is found that through intraperitoneal administration, FITC-ChG is absorbable, biodegradable and can be excreted rapidly. The main pathway of excretion of FITC-ChG is blood absorption, liver degradation and urinary excretion, 88% of the injected gel dose can be excreted in urine over the period of 17days .And the gel permeation chromatography (GPC) analysis indicate that the gel has undergone an objective degradation process, the molecular weight of the FITC-ChG can be degraded from over 200kDa to less than 10kDa in 24h. All the results demonstrate that ChG has excellent bioavailability and biodegradability, which suggests its promising applications in the biomedical area
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  Preparation of L-Asparagine molecularly imprinted polymer using Ionic liquid as cosolvent

  Xiang-rong ZHANG

  . 2014, 45(14-生物): 3-0.

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  The molecularly imprinted polymers (L-Asn-MIPs-IL) were firstly prepared by precipitation polymerization using 4-vinylpyridine(4-VP) as functional monomers and ethylene glycol dimethyl acrylate(EGDMA) as cross-linker in the presence of L-Asparagine as template molecule in aqueous-acetonitrile and 1-butyl-3-methylimidazolium bromide [Bmim]Br solution. The scanning electron microscopy (SEM) exhibited that the L-Asn-MIPs-IL were small particles with narrow particle size distributions. Compared with that of the molecularly imprinted polymers (L-Asn-MIPs) synthesized in aqueous-acetonitrile solution without [Bmim]Br, the yield and specific surface area of L-Asn-MIPs-IL was significantly higher. The results showed that L-Asn-MIPs-IL for L-Asn possessed higher saturation adsorption amount, faster adsorption speed, better selective adsorption capacity and finer separation property for the enantiomers of Asparagine compared to L-Asn-MIPs. The equilibrium adsorption amount in 100mg/L L-Asn solution was 15.49mg/g, the adsorption equilibrium can be reached within 160 minutes and the separation factor between L-Asn and L-Arg is 1.68.
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  The preparation of regenerated cellulose/collagen composite wound dressing and its performance evaluation

  Jing-Hua CHEN

  . 2014, 45(14-生物): 4-0.

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  In this study, an approach to prepare regenerated cellulose/collagen composite dressing was proposed. Firstly, regenerated cellulose membrane was oxidized by periodate oxidation for the preparation of 2,3-dialdehyde cellulose (DARC, the dialdehyde content was 6.11%), and then it was reacted with collagen to obtain the target DARC-Col composite dressing by Schiff base reaction. The scanning electron microscopy revealed that DARC-Col composite dressing exhibited the refined network structures. In addition, the composite dressing showed novel mechanical properties (the strain was 78.09 MPa, the stress was 9.59%), good equilibrium-swelling ratio (182%), good air permeability (703.72 g/m2?d) and excellent water retaining property (20%). Furthermore, the test of NIH3T3 mice fibroblast cells indicated that DARC-Col could promote cell growth and proliferation. The DARC-Col composite composite dressing showed great potential as ideal wound dressing for the wound repair application.