The micro/nanoparticles and microspheres of polyesters derived from the heterocyclic monomers of lactide (L,L or D,L), ε-caprolactone, and glycolide have received significant interest as drug carriers for biomedical applications. This review focuses on the recent advances in the study of polyester-based micro/nanoparticles and microspheres derived from the dispersion ring-opening polymerization (ROP) of heterocyclic monomers, and/or self-assembly of polyester macromolecules, and/or dialysis of polyester solution in water-miscible organic solvents against water. The dispersion polymerization of heterocyclic monomers in the presence of non-polar miscible solvents and amphiphilic polymer surfactant leads to the formation of polyester particles with a narrower size distribution. The use of the polymer surfactant is crucial in controlling the diameter, morphology, and stability of the polyester particles formed during the ROP. The polymer surfactant acts as a stabilizer and is bound to the polyester particles strongly and irreversibly to control the size and morphology of polyester microspheres. The properties of polyester particles are varied by controlling the number average diameter and diameter polydispersity index. Hence, in this article, we review different synthetic strategies developed for the formation of polyester based particles with controlled diameter of distribution and the factors influencing its formation such as structure of the polymer surfactant, critical micelle concentration of the surfactant, type of radical initiator/monomer used, reaction parameters, etc. The article also describes methods developed for transforming the polyester microspheres into the water for better biocompatibility and encapsulation of bioactive compounds, drugs, and proteins into the polyester particles and their potential release at the targeted specific site are reviewed.

中文翻译：

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通过分散开环聚合从聚酯形成微/纳米颗粒和微球

衍生自丙交酯（L，L 或 D，L）、ε-己内酯和乙交酯的杂环单体的聚酯微/纳米颗粒和微球作为生物医学应用的药物载体受到了极大的关注。本综述重点介绍了杂环单体的分散开环聚合 (ROP) 和/或聚酯大分子的自组装和/或聚酯的透析衍生的聚酯基微/纳米颗粒和微球的研究进展溶于水的有机溶剂中的溶液。在非极性混溶溶剂和两亲性聚合物表面活性剂存在下，杂环单体的分散聚合导致形成具有更窄尺寸分布的聚酯颗粒。聚合物表面活性剂的使用对于控制直径至关重要，ROP 过程中形成的聚酯颗粒的形态和稳定性。聚合物表面活性剂起到稳定剂的作用，与聚酯颗粒牢固且不可逆地结合，以控制聚酯微球的尺寸和形态。通过控制数均直径和直径多分散指数来改变聚酯颗粒的性能。因此，在本文中，我们回顾了为形成具有受控分布直径的聚酯基颗粒而开发的不同合成策略以及影响其形成的因素，例如聚合物表面活性剂的结构、表面活性剂的临界胶束浓度、自由基引发剂的类型/使用的单体、反应参数等。