交联聚乳酸中空微球的制备与表征

由于聚乳酸具有良好生物相容性与降解性，故可用作控释给药系统的载体材料．有关聚乳酸及其共聚物微球药物载体、释放行为及微球表面引入基团使之功能化的方法研究已有报道．以其它生物大分子材料作为囊壁材料的缓释微胶囊也有报道，但以聚乳酸制备中空微囊型的药物释放载体却鲜有研究．通过控制分子量、微囊大小、囊壁厚度等参数，

Preparation and Characterization of Cross-linked Hollow Poly(lactic acid) Microspheres

Poly(lactic acid) macromonomer with a double bond at its end was synthesized by ring open polymerization of lactide catalyzed by stannous chloride in the presence of allyloxylethanol(AOE) as a co-initiator. Its molecular weight was decreased along with the adding amount of AOE. Initiated by an oxidation-reduction system, e.g. K2S2O8 and Na2SO3, the poly(latic acid) macromonomers were copolymerized with divinylbenzene and methacrylic acid in a water-in-oil-in-water emulsion manner to produce hollow microspheres with a size of hundreds nanometers. Their hollow structure was confirmed by transmission electron microscopy. Infrared spectroscopy measurement shows that the remainings of the microspheres after tetrahydrofuran extraction, constituting roughly 20 of the sphere's mass, contained all the initial monomer components. This provides a new pathway for fabricating biodegradable hollow microspheres with rather smaller size, which may find diverse applications in the fields of drug delivery, tissue engineering and nanotechnology.