Department of Protein Science, School of Chemistry, Biotechnology and Health (CBH), KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden.
Spiber Technologies AB, Roslagstullsbacken 15, 114 21 Stockholm, Sweden.
ACS Appl Bio Mater. 2023 Sep 18;6(9):3696-3705. doi: 10.1021/acsabm.3c00373. Epub 2023 Aug 14.
Biomaterials made of self-assembling protein building blocks are widely explored for biomedical applications, for example, as drug carriers, tissue engineering scaffolds, and functionalized coatings. It has previously been shown that a recombinant spider silk protein functionalized with a cell binding motif from fibronectin, FN-4RepCT (FN-silk), self-assembles into fibrillar structures at interfaces, i.e., membranes, fibers, or foams at liquid/air interfaces, and fibrillar coatings at liquid/solid interfaces. Recently, we observed that FN-silk also assembles into microspheres in the bulk of a physiological buffer (PBS) solution. Herein, we investigate the self-assembly process of FN-silk into microspheres in the bulk and how its progression is affected by the presence of hyaluronic acid (HA), both in solution and in a cross-linked HA hydrogel. Moreover, we characterize the size, morphology, mesostructure, and protein secondary structure of the FN-silk microspheres prepared in PBS and HA. Finally, we examine how the FN-silk microspheres can be used to mediate cell adhesion and spreading of human mesenchymal stem cells (hMSCs) during cell culture. These investigations contribute to our fundamental understanding of the self-assembly of silk protein into materials and demonstrate the use of silk microspheres as additives for cell culture applications.
基于自组装蛋白构建块的生物材料被广泛探索用于生物医学应用，例如作为药物载体、组织工程支架和功能化涂层。先前已经表明，一种由源自纤连蛋白的细胞结合基序功能化的重组蜘蛛丝蛋白 FN-4RepCT（FN-丝），在界面处自组装成纤维状结构，即在液体/空气界面处的膜、纤维或泡沫，以及在液体/固体界面处的纤维状涂层。最近，我们观察到 FN-丝也在生理缓冲液（PBS）溶液的本体中组装成微球。在此，我们研究了 FN-丝在本体中自组装成微球的过程，以及其进展如何受到透明质酸（HA）的存在的影响，无论是在溶液中还是在交联的 HA 水凝胶中。此外，我们还表征了在 PBS 和 HA 中制备的 FN-丝微球的大小、形态、介观结构和蛋白质二级结构。最后，我们研究了 FN-丝微球如何用于在细胞培养过程中调节人间充质干细胞（hMSC）的细胞黏附和铺展。这些研究有助于我们对丝蛋白自组装成材料的基本理解，并展示了丝微球作为细胞培养应用添加剂的用途。
