具生物活性的快速光交联生物可降解水凝胶的设计合成

采用开环聚合方法合成了一系列水溶性生物可降解的低聚(丙交酯-co-丙烯酸酯碳酸酯)-b-聚乙二醇-b-低聚(丙交酯-co-丙烯酸酯碳酸酯)(OLAC-PEG-OLAC)三嵌段共聚物,并通过光交联方法方便制备得到具生物活性的新型生物可降解水凝胶.流变测试表明水凝胶储存模量(170～10000 Pa)和凝胶时间(0.8～8min)均可通过调节丙烯酸酯碳酸酯(AC)单元数、聚合物浓度及光引发剂浓度等得到控制.降解实验表明水凝胶的降解速率可通过改变AC和丙交酯(LA)单元数进行调控.含巯基的生物活性分子如RGDC短肽可通过迈克尔加成反应直接链接到OLAC-PEG-OLAC上,由此可方便制备可注射性的具生物活性的生物可降解水凝胶.MG63成骨细胞实验表明RGDC短肽功能化的OLAC-PEG-OLAC水凝胶可很好地促进细胞黏附和生长.该快速光交联生物可降解水凝胶以其优异的凝胶、降解和生物功能化等性能可望为生物组织工程提供理想的三维活性多孔支架.

DESIGN AND SYNTHESIS OF RAPIDLY PHOTO-CROSSLINKABLE BIOACTIVE BIODEGRADABLE HYDROGELS

A series of water-soluble biodegradable oligo(lactide-co-acryloyl carbonate)-b-poly(ethylene glycol)-b-oligo(lactide-co-acryloyl carbonate)(OLAC-PEG-OLAC) triblock copolymers were synthesized by ring-opening copolymerization of lactide(LA) and acryloyl cyclic carbonate(AC) and applied for in situ formation of novel bioactive biodegradable hydrogels via photo-crosslinking.The rheology measurements showed that gelation times(0.8~8 min) and storage moduli(170~10000 Pa) of hydrogels could be controlled by AC content,polymer concentration and photo-initiator concentration.The results of degradation tests displayed that degradation rates of these hydrogels could be tailored by AC and LA contents.Notably,the multiple acryloyl functional groups in OLAC-PEG-OLAC copolymers allowed direct conjugation of thiol-containing biomolecules like RGD peptides via Michael addition reaction prior to gelation,which provides a facile access to injectable bioactive biodegradable hydrogels.The preliminary cell experiments demonstrated that RGD peptide modified hydrogels could well support adhesion and growth of MG63 osteoblast cells.These rapidly photo-crosslinkable biodegradable hydrogels with controlled mechanical properties,tailored biodegradation rates,and versatile bio-functionalization form an excellent basis for the development of advanced bioactive tissue engineering scaffolds.