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采用相分离-溶剂去除法制备纳米尺度的单甲氧基聚乙二醇-聚乳酸共聚物(PELA)微球,分析了纳米微球在溶液中的形成机理;用有机溶剂对纳米微球进行溶胀制孔,制备出具有不同孔道特征的纳米微球.结果表明,以乙醇+丙酮为油相、去离子水为水相,油相中PELA含量6.5 g/L、水相中SDS含量1%、油与水相体积比1:6、油相中乙醇含量50%((?))条件下,所制微球粒径为78.48 nm.溶胀时间为0.5 h时,以甲苯为溶胀剂所制PELA微球具有中空单孔结构,以二氯甲烷为溶胀剂所制PELA微球具有多孔结构.用相同方法制备了具有孔结构的聚乳酸、聚(乳酸-羟基乙酸)共聚物纳米微球,其与PELA的成孔趋势相同.以模拟体液考察多孔PELA纳米微球的降解性能,30 d可充分降解.
The nano-scale monomethoxy polyethylene glycol-polylactic acid copolymer (PELA) microspheres were prepared by phase separation-solvent removal method, and the formation mechanism of the nanospheres was analyzed. The nanospheres were treated with organic solvent The results showed that with ethanol + acetone as the oil phase and deionized water as the water phase, the content of PELA in the oil phase was 6.5 g / L, the content of SDS in the aqueous phase was 1% , The volume ratio of oil to water was 1: 6, and the ethanol content in oil phase was 50% ((?)), The microsphere size was 78.48 nm. When the swelling time was 0.5 h, PELA microspheres have a hollow single-pore structure, and PELA microspheres made of dichloromethane as a swelling agent have a porous structure.Polylactic acid, poly (lactic-co-glycolic acid) copolymer nanospheres with pore structure were prepared by the same method, The same tendency of PELA as that of PELA was obtained.The biodegradability of porous PELA nanospheres was investigated by simulated body fluid and fully degraded after 30 d.