Algebraistova Polina Yu, Basko Andrey V, Ilyasova Anna N, Lebedeva Tatyana N, Mironov Anton V, Pochivalov Konstantin V, Popov Vladimir K
Institute of Photonic Technologies, Federal Scientific Research Center "Crystallography and Photonics", Russian Academy of Sciences, Pionerskaya 2, Troitsk, Moscow 108840, Russia.
G.A. Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Akademicheskaya 1, Ivanovo 153045, Russia.
Polymers (Basel). 2023 Mar 3;15(5):1281. doi: 10.3390/polym15051281.
This paper concerns a detailed study of the phase separation and structure formation processes that occur in solutions of highly hydrophobic polylactic-co-glycolic acid (PLGA) in highly hydrophilic tetraglycol (TG) upon their contact with aqueous media. In the present work, cloud point methodology, high-speed video recording, differential scanning calorimetry, and both optical and scanning electron microscopy were used to analyze the behavior of PLGA/TG mixtures differing in composition when they are immersed in water (the so-called "harsh" antisolvent) or in a nonsolvent consisting of equal amounts of water and TG (a "soft" antisolvent). The phase diagram of the ternary PLGA/TG/water system was designed and constructed for the first time. The PLGA/TG mixture composition with which the polymer undergoes glass transition at room temperature was determined. Our data enabled us to analyze in detail the structure evolution process taking place in various mixtures upon their immersion in "harsh" and "soft" antisolvent baths and gain an insight into the peculiarities of the structure formation mechanism active in the course of antisolvent-induced phase separation in PLGA/TG/water mixtures. This provides intriguing opportunities for the controlled fabrication of a wide variety of bioresorbable structures-from polyester microparticles, fibers, and membranes to scaffolds for tissue engineering.
本文详细研究了高疏水性聚乳酸 - 乙醇酸共聚物（PLGA）在高亲水性四甘醇（TG）中的溶液与水性介质接触时发生的相分离和结构形成过程。在本工作中，采用浊点法、高速视频记录、差示扫描量热法以及光学显微镜和扫描电子显微镜来分析不同组成的PLGA/TG混合物在浸入水（所谓的“苛刻”抗溶剂）或由等量水和TG组成的非溶剂（“温和”抗溶剂）时的行为。首次设计并构建了三元PLGA/TG/水体系的相图。确定了聚合物在室温下发生玻璃化转变的PLGA/TG混合物组成。我们的数据使我们能够详细分析各种混合物在浸入“苛刻”和“温和”抗溶剂浴时发生的结构演变过程，并深入了解在PLGA/TG/水混合物中抗溶剂诱导相分离过程中起作用的结构形成机制的特点。这为可控制造各种生物可吸收结构提供了有趣的机会，从聚酯微粒、纤维和膜到组织工程支架。
