Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA.
Biomater Sci. 2019 Aug 20;7(9):3876-3885. doi: 10.1039/c9bm00867e.
Graphene is a valuable material in biomedical implant applications due to its mechanical integrity, long-range order, and conductivity; but graphene must be chemically modified to increase biocompatibility and maximize functionality in the body. Here, we developed a foundational synthetic method for covalently functionalizing a reduced GO with bioactive molecules, focusing on synthetic peptides that have shown osteogenic or neurogenic capability as a prototypical example. X-ray photoelectron spectroscopy provides evidence that the peptide is covalently linked to the graphenic backbone. These peptide-graphene (Pep-G) conjugate materials can be processed into mechanically robust, three-dimensional constructs. Differences in their electrostatic charges allow the Pep-G conjugates to form self-assembled, layer-by-layer coatings. Further, the Pep-G conjugates are cytocompatible and electrically conductive, leading us to investigate their potential as regenerative scaffolds, as conductive surfaces can stimulate bone and nerve regeneration. Notably, PC12 cells grown on an electrically stimulated Pep-G scaffold demonstrated enhanced adhesion and neurite outgrowth compared to the control. The functionalization strategy developed here can be used to conjugate a wide variety of bioactive molecules to graphene oxide to create cell-instructive surfaces for biomedical scaffold materials.
由于其机械完整性、长程有序性和导电性，石墨烯在生物医学植入物应用中是一种有价值的材料；但石墨烯必须进行化学修饰以提高生物相容性并最大限度地发挥其在体内的功能。在这里，我们开发了一种将生物活性分子共价功能化还原 GO 的基础合成方法，重点是已显示出成骨或神经生成能力的合成肽作为典型示例。X 射线光电子能谱提供了证据，证明肽与石墨烯主链共价连接。这些肽-石墨烯（Pep-G）缀合物材料可以加工成机械坚固的三维结构。它们的静电电荷差异允许 Pep-G 缀合物自组装形成层层涂层。此外，Pep-G 缀合物具有细胞相容性和导电性，这促使我们研究它们作为再生支架的潜力，因为导电表面可以刺激骨骼和神经再生。值得注意的是，与对照相比，在电刺激 Pep-G 支架上生长的 PC12 细胞表现出增强的粘附和神经突生长。这里开发的功能化策略可用于将各种生物活性分子缀合到氧化石墨烯上，以创建用于生物医学支架材料的细胞指令表面。
