Acta Chim. Sinica ›› 2015, Vol. 73 ›› Issue (10): 1038-1046.DOI: 10.6023/A15050317 Previous Articles     Next Articles



任锴a, 何金林a, 张明祖a, 吴一弦b, 倪沛红a   

  1. a 苏州大学材料与化学化工学部 苏州市大分子设计与精密合成重点实验室 江苏省先进功能高分子材料设计及应用重点实验室 苏州 215123;
    b 北京化工大学材料科学与工程学院 化工资源有效利用国家重点实验室 北京 100029
  • 投稿日期:2015-05-09 发布日期:2015-07-07
  • 通讯作者: 倪沛红
  • 基金资助:


Synthesis and Characterization of pH-Sensitive Copolymer mPEG-acetal-PIB and Fabrication of Hydrogel for Wound Dressing

Ren Kaia, He Jinlina, Zhang Mingzua, Wu Yixianb, Ni Peihonga   

  1. a College of Chemistry, Chemical Engineering and Materials Science, Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, Soochow University, Suzhou 215123;
    b Beijing University of Chemical Technology, State Key Laboratory of Chemical Resource Engineering, Beijing 100029
  • Received:2015-05-09 Published:2015-07-07
  • Supported by:

    roject supported by the National Natural Science Foundation of China (No. 21374066), the Suzhou Science and Technology Program for Industrial Application Foundation (No. SYG201429), a Project Funded by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions, and the State Key Lab of Chemical Resource Engineering (Beijing University of Chemical Technology) (No. CRE-2014-C-202).

An acetal-linked amphiphilic diblock copolymer, poly(ethylene glycol) methyl ether-acetal-polyisobutene (abbreviated as mPEG-acetal-PIB), was synthesized via Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) “Click” reaction. The chemical composition and structures of the copolymers were characterized by 1H NMR and FT-IR analysis. The molecular weights and molecular weight distributions of the polymers were measured by gel permeation chromatography (GPC). The critical aggregation concentration (CAC), particle size parameters and morphologies of micelles self-assembled from mPEG-acetal-PIB in aqueous solution were determined by fluorescence probe method, dynamic light scattering (DLS), and transmission electron microscopy (TEM), respectively. The results showed that this amphiphilic diblock copolymer mPEG-acetal-PIB could self-assemble into spherical micelles in aqueous solution, and the average particle size of micelles was about 100 nm. Since the acetal group is unstable in weak acidic medium, it is anticipated that the diblock copolymer micelles can be dissociated in acidic environment. To verify this, DLS analysis was used to monitor the size change of micelles with the increase of degradation time under the acidic conditions. The degradation of acetal group in acidic environment resulted in the aggregation of PIB, which caused the increase of particle size. Subsequently, a-cyclodextrin (a-CD) was added into the micellar system to interact with PEG chain via inclusion complexation, resulting in the formation of physical-crosslinked supramolecular hydrogels. X-ray diffraction (XRD) was carried out to analyze the inclusion complexation and rheological test was used to monitor the gelation kinetics of hydrogels. The materials chosen to fabricate wound dressing should have good biocompatibility, thus in vitro cytotoxicity tests against L929 cells by MTT assays was carried out to study the biocompatibility of the copolymer and hydrogel. The results showed that the viability of L929 cells incubated with both the copolymer and hydrogel were higher than 80%, indicating that the copolymer and hydrogel displayed low cytotoxicity. This biocompatible hydrogel provides a moist and cool environment on the wounds and can be degraded in the acidic conditions, reducing the risk of inflammation. Therefore, it will possess great potential in the application of wound dressing.

Key words: “Click&rdquo, reaction, pH-response, hydrogel, wound dressing