School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310027 Zhejiang, P. R. China.
Institute of Applied Bioresource Research, College of Animal Science, Zhejiang University, Yuhangtang Road 866, Hangzhou, 310058 Zhejiang, P. R. China.
ACS Appl Mater Interfaces. 2022 Jan 12;14(1):350-360. doi: 10.1021/acsami.1c20740. Epub 2021 Dec 28.
Graphene paper (GP), a macroscopic self-supporting material, has exceptional flexibility and preserves the excellent physical and chemical properties of graphene nanomaterials. But its applications in regenerative medicine remain to be further explored. Here, we biologically functionalized GP with hydroxyapatite (HA) nanorods by the use of GP-binding peptides as an affinity linker. This strategy solved two daunting challenges for regenerative medicine applications of GP: the lack of good hydrophilicity for supporting cell growth and the difficulty in forming composites by binding with nanobiomaterials. Briefly, we first screened a high-affinity GP-binding peptide (TWWNPRLVYFDY) by the phage display technique. Then we chemically conjugated the GP-binding peptide to the synthetic HA nanorods. The GP-binding peptide on the resultant HA nanorods enabled them to be bound and assembled onto the GP substrate with high affinity, forming a GP-peptide-HA composite with significantly improved hydrophilicity of GP. The composite promoted the attachment and proliferation of mesenchymal stem cells (MSCs), demonstrating its outstanding biocompatibility. Due to the unique compositions of the composite, it was also found to induce osteogenic differentiation of MSCs in vitro in the absence of other inducers in the medium, by verifying the expression of the osteogenic markers including collagen-1, bone morphogenetic proteins 2, runx-related transcription factor 2, osteocalcin, and alkaline phosphatase. Our work suggests that the GP-binding peptide can be used to link inorganic nanoparticles onto GP to facilitate the biomedical applications of GP.
石墨烯纸（GP）是一种宏观的自支撑材料，具有出色的柔韧性，并保留了石墨烯纳米材料的优异物理和化学性质。但其在再生医学中的应用仍有待进一步探索。在这里，我们使用 GP 结合肽作为亲和接头，将羟基磷灰石（HA）纳米棒生物功能化到 GP 上。该策略解决了 GP 在再生医学应用中面临的两个艰巨挑战：缺乏支持细胞生长的良好亲水性和与纳米生物材料结合形成复合材料的困难。简而言之，我们首先通过噬菌体展示技术筛选出高亲和力的 GP 结合肽（TWWNPRLVYFDY）。然后，我们将 GP 结合肽化学偶联到合成的 HA 纳米棒上。所得 HA 纳米棒上的 GP 结合肽使它们能够以高亲和力结合到 GP 基底上并组装在一起，形成具有显著提高 GP 亲水性的 GP-肽-HA 复合材料。该复合材料促进了间充质干细胞（MSCs）的附着和增殖，表现出出色的生物相容性。由于复合材料的独特组成，还发现它可以在没有培养基中其他诱导剂的情况下诱导 MSCs 的体外成骨分化，通过验证成骨标志物的表达，包括胶原-1、骨形态发生蛋白 2、与 runt 相关转录因子 2、骨钙素和碱性磷酸酶。我们的工作表明，GP 结合肽可用于将无机纳米颗粒连接到 GP 上，以促进 GP 的生物医学应用。
