Lee Wei Li, Hong Meiju, Widjaja Effendi, Loo Say Chye Joachim
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.
Macromol Rapid Commun. 2010 Jul 1;31(13):1193-200. doi: 10.1002/marc.200900811. Epub 2010 Mar 9.
In this work, we report how biodegradable triple-layered microparticles can be fabricated through a simple, reliable, and economical one-step solvent evaporation technique. Characterization of triple-layered PLGA (shell)/PLLA (middle layer)/EVA (core) microparticles was conducted and their formation mechanism was described. Subsequently, in vitro hydrolytic degradation of these microparticles was investigated. It was found that the PLGA shell degraded rapidly leaving behind double-walled microparticles of PLLA/EVA after 40 days. The middle PLLA layer degraded more rapidly than expected because of the migration of PLGA oligomers that created a hydrophilic and acidic microenvironment in the PLLA layer. These degradation results therefore provide important insights into how triple-layered microparticles degrade, and how their degradation characteristics affect the drug releasing properties of these novel microparticles.
在本研究中，我们报告了如何通过一种简单、可靠且经济的一步溶剂蒸发技术制备可生物降解的三层微粒。对三层聚乳酸-羟基乙酸共聚物（PLGA）（壳层）/聚乳酸（PLLA）（中间层）/乙烯-醋酸乙烯共聚物（EVA）（核心）微粒进行了表征，并描述了它们的形成机制。随后，研究了这些微粒的体外水解降解情况。结果发现，40天后PLGA壳层迅速降解，留下PLLA/EVA双层微粒。由于PLGA低聚物的迁移，中间的PLLA层降解速度比预期更快，这在PLLA层中创造了一个亲水性和酸性的微环境。因此，这些降解结果为三层微粒的降解方式以及它们的降解特性如何影响这些新型微粒的药物释放性能提供了重要的见解。
