In situ forming stereocomplexed and post-photocrosslinked acrylated star poly(ethylene glycol)-poly(lactide) hydrogels
In situ forming stereocomplexed and post-photocrosslinked acrylated star poly(ethylene glycol)-poly(lactide) hydrogels
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DOI：
10.1016/j.eurpolymj.2017.07.002
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发表时间：
2017-09-01
影响因子：
6
通讯作者：
Feijen, Jan
中科院分区：
文献类型：
--
作者：
Buwalda, Sytze J.;Dijkstra, Pieter J.;Feijen, Jan
通过星形聚乙二醇聚乳酸(PLLA)(8)和聚乙二醇聚丙交酯(PDLA)(8)对映体的立体络合和紫外光聚合，通过连续的物理凝胶化，形成了可生物降解的端基功能化聚乙二醇聚(丙交酯)星形嵌段共聚水凝胶。以辛酸亚锡为催化剂，通过丙交酯在端胺基官能团聚乙二醇胺上开环聚合，制备了8臂聚乙二醇聚乳酸星形嵌段共聚物。聚乳酸嵌段的聚合度为12个乳基单位，端羟基与丙烯酰氯反应得到所需的丙烯酸酯端基。在临界凝胶浓度为4w/v%以上，聚乙二醇-(聚乳酸)(8)大单体对映体混合物的水溶液形成物理交联水凝胶。随后在Irgacure 2959的存在下，在365 nm处进行光聚合，得到了具有更好的机械性能和水解稳定性的凝胶。这些水凝胶在体外45d后有40%的聚合物质量损失，表现出优异的抗水解性和耐溶解性，这被认为是由于聚乙二醇和聚乳酸嵌段之间稳定的酰胺键和星形结构导致的高物理和化学交联度的结合。
Biodegradable acrylate end-group functionalized poly(ethylene glycol)-poly(lactide) (PEG-PLA) star block copolymer hydrogels were formed by the consecutive physical gelation through stereocomplexation of star shaped PEG-(PLLA)(8) and PEG-(PDLA)(8) enantiomers and UV photo-polymerization. The 8-armed PEG-PLA star block copolymers were prepared by ring opening polymerization of lactide onto an amine end-group functionalized PEG with a molecular weight of 20 kg/mol using stannous octoate as a catalyst. The degree of polymerization of the PLA blocks was 12 lactyl units and the end hydroxyl groups were reacted with acryloyl chloride to give the required acrylate end groups. Aqueous solutions of enantiomeric mixtures of the PEG-(PLA)(8) macromonomers formed physically crosslinked hydrogels above a critical gel concentration of 4 w/v%. Subsequent photopolymerization at 365 nm in the presence of Irgacure 2959 resulted in gels with improved mechanical properties and hydrolytic stability. With 40% polymer mass loss after 45 d in vitro, these hydrogels show excellent resistance against hydrolytic degradation and dissolution, which is believed to result from the combination of stable amide linkages between the PEG and PLA blocks and the high physical and chemical crosslink density owing to the star architecture.