Centre of Polymer Systems, Tomas Bata University in Zlín, Trida Tomase Bati 5678, Zlín, 760 01, Czech Republic.
Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt.
J Biomed Mater Res A. 2017 Nov;105(11):3176-3188. doi: 10.1002/jbm.a.36158. Epub 2017 Sep 15.
Poly(lactic acid) (PLA) has shown much success in the preparation of tissue engineering scaffolds as it can be fabricated with a tailored architecture. However, the PLA surface has drawbacks including the lack of biofunctional motifs which are essential for high affinity to biological cells. Therefore, this study describes a multistep physicochemical approach for the immobilization of d-glucosamine (GlcN), a naturally occurring monosaccharide having many biological functions, on the PLA surface aiming at enhancing the cell proliferation activity. In this approach, poly(acrylic acid) (PAAc) spacer arms are first introduced into the PLA surface via plasma post-irradiation grafting technique. Then, covalent coupling or physical adsorption of GlcN with/on the PAAc spacer is carried out. Factors affecting the grafting yield are controlled to produce a suitable spacer for bioimmobilization. X-ray photon spectroscopic (XPS) analyses confirm the immobilization of GlcN on the PLA surface. The XPS results reveal also that increasing the yield of grafted PAAc spacer on the PLA surface increases the amount of covalently immobilized GlcN, but actually inhibits the immobilization process using the physical adsorption method. Contact angle measurements and atomic force microscopy (AFM) show a substantial increase of surface energy and roughness of PLA surface, respectively, upon the multistep modification procedure. The cytocompatibility of the modified surfaces is assessed using a mouse embryonic fibroblast (MEF) cell line. Observation from the cell culture basically demonstrates the potential of GlcN immobilization in improving the cytocompatibility of the PLA surface. Moreover, the covalent immobilization of GlcN seems to produce more cytocompatible surfaces if compared with the physical adsorption method. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3176-3188, 2017.
聚乳酸（PLA）在组织工程支架的制备中取得了很大的成功，因为它可以通过定制的结构进行制造。然而，PLA 表面存在一些缺点，包括缺乏对生物细胞具有高亲和力的生物功能基序。因此，本研究描述了一种多步物理化学方法，将天然存在的具有多种生物学功能的单糖 d-葡萄糖胺（GlcN）固定在 PLA 表面上，旨在提高细胞增殖活性。在这种方法中，首先通过等离子体后辐照接枝技术将聚（丙烯酸）（PAAc）间隔臂引入 PLA 表面。然后，通过共价偶联或物理吸附将 GlcN 与/或在 PAAc 间隔臂上进行偶联。控制影响接枝产率的因素，以产生适合生物固定化的间隔臂。X 射线光电子能谱（XPS）分析证实了 GlcN 固定在 PLA 表面上。XPS 结果还表明，增加 PLA 表面接枝 PAAc 间隔臂的产率会增加共价固定化的 GlcN 量，但实际上会抑制使用物理吸附方法的固定化过程。接触角测量和原子力显微镜（AFM）分别显示，在多步修饰过程中，PLA 表面的表面能和粗糙度都有显著增加。使用小鼠胚胎成纤维细胞（MEF）细胞系评估改性表面的细胞相容性。从细胞培养的观察结果基本表明，GlcN 固定化具有提高 PLA 表面细胞相容性的潜力。此外，如果与物理吸附方法相比，GlcN 的共价固定化似乎产生了更具细胞相容性的表面。© 2017 Wiley Periodicals, Inc. J 生物材料 Res 部分 A：105A：3176-3188，2017。
