Different compositional parameters of poly(_D,L‐lactic‐co‐glycolic acid)‐b‐poly(ethylene glycol) triblock copolymers (PLGA‐PEG) were varied to analyze their effect on gel formation and mechanical properties. Parameters such as hydrophilic/hydrophobic ratio (PLGA/PEG ratio), lactic acid/glycolic acid ratio (LA/GA ratio), PEG molecular weight (PEG Mw), polymer solution concentration, copolymer molecular weight (Mw), and polydispersity index (PDI) were studied in this work. For copolymers with PEG Mw of 1500 Da, gelation temperature (34–37 °C) was affected by _D,L‐LA/GA ratio and Mw; while modulus was affected by LA/GA ratio, Mw, and Mn. Based on the parametric study, an injectable, thermoresponsive hyaluronic acid (HA) delivery platform was designed for ocular applications. PLGA‐PEG copolymers with _D,L‐LA/GA ratio of 15/1, PLGA/PEG ratio of 2/1, PEG Mw of 1500 Da, and Mw of about 6 KDa gelled at 35 °C, were optically transparent, had a modulus less than 350 Pa and were used for HA release studies. This work also demonstrates, for the first time, an extended and controlled release of HA, beyond 2 weeks, from injectable hydrogels modified with a noncovalent interacting agent, poly(L‐lysine). Smaller PLL chains slowed down the HA release kinetics, while larger PLL chains produced a release profile similar to the nonmodified hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48678.

中文翻译：

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两性PLGA-PEG-PLGA三嵌段共聚物纳米凝胶，凝胶温度和模量各不相同，可延长和控制透明质酸的释放

聚的不同组成参数（_d，L-乳酸-共-glycolic酸） - b -聚（乙二醇）三嵌段共聚物（PLGA-PEG）被改变，以分析其对凝胶形成和机械性能的影响。参数包括亲水/疏水比（PLGA / PEG比），乳酸/乙醇酸比（LA / GA比），PEG分子量（PEG Mw），聚合物溶液浓度，共聚物分子量（Mw）和多分散指数（ PDI）在这项工作中进行了研究。对于PEG Mw为1500 Da的共聚物，胶凝温度（34–37°C）受_D，L-LA / GA比和Mw；而模量受LA / GA比，Mw和Mn的影响。基于参数研究，设计了一种可注射的热响应性透明质酸（HA）输送平台，用于眼科应用。具有_D，L-的PLGA-PEG共聚物在35°C下胶凝的LA / GA比为15/1，PLGA / PEG比为2/1，PEG Mw为1500 Da，Mw为约6 KDa，它们是光学透明的，模量小于350 Pa，可以使用用于HA释放研究。这项工作还首次证明了用非共价相互作用剂聚（L-赖氨酸）修饰的可注射水凝胶在超过2周的时间内可延长和控制性释放HA。较小的PLL链减慢了HA的释放动力学，而较大的PLL链产生的释放曲线类似于未改性的水凝胶。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 2020，137，48678。