酸敏感型嵌段共聚物mPEG-acetal-PIB的合成、表征及用于构筑水凝胶敷料  

Synthesis and Characterization of pH-Sensitive Copolymer m PEG-acetalPIB and Fabrication of Hydrogel for Wound Dressing

作　　者：任锴[1] 何金林[1] 张明祖[1] 吴一弦[2] 倪沛红[1] 

机构地区：[1]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 [2]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

出　　处：《化学学报》2015年第10期1038-1046,共9页Acta Chimica Sinica

基　　金：国家自然科学基金项目(No.21374066);苏州市科技发展计划工业应用基础研究项目(No.SYG201429);江苏省高校优势学科建设项目(PAPD);化工资源有效利用国家重点实验室(北京化工大学)开放课题(No.CRE-2014-C-202)项目资助~~

摘　　要：利用点击化学('Click')反应,成功制备了一种通过酸敏感缩醛基团键合的两亲性嵌段共聚物,聚乙二醇单甲醚-acetal-聚异丁烯(简写为m PEG-acetal-PIB).通过核磁共振氢谱(1H NMR)、红外光谱(FT-IR)和凝胶渗透色谱(GPC)对聚合物的结构、分子量及分子量分布进行表征.利用芘荧光探针法、动态激光光散射(DLS)和透射电子显微镜(TEM),研究共聚物在水溶液中组装的临界聚集浓度(CAC),胶束的粒径大小、分布以及形貌.利用DLS跟踪测试聚合物胶束在酸性条件下的粒径变化,验证m PEG-acetal-PIB的酸敏感性质.随后,在体系中引入α-环糊精(α-CD),诱导形成超分子水凝胶.利用X射线衍射(XRD)分析PEG与α-CD的包结络合作用,流变仪测试水凝胶的凝胶化时间和黏弹性.通过体外细胞毒性试验(MTT法)证明嵌段共聚物m PEG-acetal-PIB及水凝胶均具有良好的生物相容性.这种水凝胶能够保持创面湿润,具有温和的冷却作用,并且由于其带有酸敏感基团,能够在偏酸性环境降解,减少炎症发生率,在水凝胶创伤敷料中具有潜在的应用.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, α-cyclodextrin （α-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 ceils by MTT assays was carried out to study the biocompatibility of the copolymer and hydrogel. The results showed that the via

关 键 词：“点击”化学 酸敏感 水凝胶 创伤敷料 

分 类 号：TQ317[化学工程—高聚物工业]