Protein-coated polymer-based microparticles are attractive supports for cell delivery, but the interplay between microparticle properties, protein coating, and cell response is poorly understood. The interest in alternative microparticle formulations increases the need for a better understanding of how functional protein coatings form on different microparticles. In this work, microparticle formulations based on biodegradable polymers [poly (lactic-co-glycolic acid) (PLGA) and the triblock copolymer PLGA-poloxamer-PLGA] were prepared via an emulsion-based process. To explore the impact that the use of a surfactant has on the properties of the microparticles, the emulsion was stabilized by using either a surfactant, poly(vinyl alcohol), or an organic solvent, propylene glycol. Four different types of microparticles were prepared through combinations of the two types of polymers and the two types of stabilizers. The coating of microparticles with proteins/polypeptides such as fibronectin and poly-d-lysine has been demonstrated before and is an integral step for their application as microcarriers, e.g., for cell delivery; however, the impact of the microparticles’ surface chemical properties on the formation (prevalence and distribution) of the mixed polypeptide coatings and the influence on subsequent cell attachment remain to be elucidated. Using a colocalization analysis approach on ToF-SIMS images of protein-coated microparticles, we show that the use of propyleneglycol over PVA as well as the substitution of PLGA by the triblock copolymer resulted in enhanced protein adsorption. Furthermore, if propyleneglycol is used, the substitution of PLGA with the triblock copolymer leads to increased stem cell adhesion.

中文翻译：

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将聚合物微粒制剂与纤连蛋白和聚-d-赖氨酸的流行或分布联系起来，以支持间充质干细胞的生长。

蛋白质包被的聚合物基微粒是细胞递送的有吸引力的支持物，但对微粒特性、蛋白质包被和细胞反应之间的相互作用知之甚少。对替代微粒配方的兴趣增加了更好地了解功能性蛋白质涂层如何在不同微粒上形成的需求。在这项工作中，基于生物可降解聚合物[聚（乳酸-微粒制剂共-乙醇酸）（PLGA）和三嵌段共聚物 PLGA-泊洛沙姆-PLGA]是通过基于乳液的方法制备的。为了探索使用表面活性剂对微粒性质的影响，通过使用表面活性剂聚（乙烯醇）或有机溶剂丙二醇来稳定乳液。通过两种类型的聚合物和两种类型的稳定剂的组合，制备了四种不同类型的微粒。用蛋白质/多肽如纤连蛋白和聚-d包被微粒-赖氨酸之前已经被证明并且是将它们用作微载体（例如用于细胞递送）的不可或缺的步骤；然而，微粒的表面化学性质对混合多肽涂层的形成（普遍性和分布）的影响以及对随后细胞附着的影响仍有待阐明。对蛋白质包被微粒的 ToF-SIMS 图像使用共定位分析方法，我们表明在 PVA 上使用丙二醇以及用三嵌段共聚物取代 PLGA 导致蛋白质吸附增强。此外，如果使用丙二醇，用三嵌段共聚物取代 PLGA 会导致干细胞粘附增加。