摘要
首先利用聚乙二醇单甲醚(MePEG)作为引发剂前体,对含有炔基的环状磷酸酯单体2-炔丁基-2-氧代-1,3,2-二氧磷杂环戊烷(BYP)进行开环聚合,制备两嵌段共聚物MePEG-b-PBYP.随后,采用巯基-炔(Thiol-yne)点击化学反应对PBYP的炔基进行修饰,分别获得侧链含氨基(—NH2)、羧基(—COOH)和磺酸钠(—SO3Na)的聚磷酸酯嵌段共聚物,在水相中形成聚电解质.通过NMR和GPC对产物的结构和组成进行表征.MTT测试表明,两嵌段共聚物具有较好的生物相容性.进一步将带有不同电荷的聚电解质溶液混合,利用静电作用制备微凝胶.通过DLS、TEM及SEM等测试对聚合物的溶液行为及微凝胶的形貌进行表征.为增强凝胶体系的物理交联作用,将α-环糊精(α-CD)引入体系,诱导形成水凝胶.利用SEM对水凝胶的形貌进行表征,XRD分析水凝胶的包结络合作用,并利用流变仪测试水凝胶的凝胶化时间.该水凝胶以其良好的生物相容性、生物可降解性和一定的机械强度等性能,有望作为可注射型凝胶材料,在药物控释和组织工程等领域具有潜在的应用.
A series of diblock copolymers MePEG-b-PBYP were firstly synthesized by the ring-opening polymerization of 2-（ but-3-yn-l-yloxy）-2-oxo-1,3,2-dioxaphospholane （BYP） using polyethylene glycol monomethyl ether （MePEG） as the macroinitiator and Sn （Oct）2 as catalyst. Subsequently, the alkyne groups on PBYP blocks were modified with three mercaptans by thiol-yne click reaction to yield polyphosphoester- based diblock copolymer with various pendant functional groups （--NH2,-COOH and --SO3 Na）. The molecular structures, molecular weights, and molecular weight distributions of the block copolymers were characterized by NMR and GPC analyses. MTT assay indicated that these block copolymers show relatively low cytotoxicity against L929 fibroblast cells. The microgels were prepared through electrostatic interaction between these oppositely-charged polyelectrolytes. The particle size, zeta potential and morphologies of the particles were also analyzed by DLS and TEM techniques. In order to enhance the physical crosslinking,α-cyclodextrin （a- CD） was added into the system to interact with PEG chain via inclusion complexation, resulting in the formation of stronger crosslinked hydrogels. SEM was utilized to observe the surface morphologies of microgels and hydrogels,XRD was used to analyze the inclusion complexation and rheology test was employed to monitor the gelation kinetics of the hydrogels. These biodegradable hydrogels with good biocompatibility and favorable mechanical properties provide a promising injectable material and have potential applications in the fields of controlled drug delivery and tissue engineering.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2014年第1期122-130,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号21074078
20974074)
江苏省基础研究计划(自然科学基金)滚动项目(基金号BK2011045)
江苏高校优势学科建设工程项目(项目号YX10900112)
江苏省2012年普通高校研究生科研创新计划项目(项目号CXLX12_0789)资助
