Institute for Biophysics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany.
Advanced Ceramics, University of Bremen, Am Biologischen Garten 2, 28359 Bremen, Germany.
ACS Appl Bio Mater. 2021 Feb 15;4(2):1852-1862. doi: 10.1021/acsabm.0c01538. Epub 2021 Feb 1.
During wound healing, a complex cascade of cellular and molecular events occurs, which is governed by topographical and biochemical cues. Therefore, optimal tissue repair requires scaffold materials with versatile structural and biochemical features. Nanoporous anodic aluminum oxide (AAO) membranes exhibit good biocompatibility along with customizable nanotopography and antimicrobial properties, which has brought them into the focus of wound treatment. However, despite their good permeability, such bioinert ceramic nanopores cannot actively promote cell growth as they lack biochemical cues to support specific ligand-receptor interactions. Therefore, we modified AAO nanopores with the biochemical features of collagen nanofibers or amino groups provided by silanization with (3-aminopropyl)triethoxysilane (APTES) to design a permeable scaffold material that can additionally promote cell adhesion. Viability assays revealed that the metabolic activity of both 3T3 fibroblasts and HaCaT keratinocytes on bare and silanized AAO pores was comparable to glass controls until 72 h. Interestingly, both cell types showed a reduced proliferation on AAO with collagen nanofibers. Nevertheless, scanning electron and fluorescence microscopy revealed that 3T3 fibroblasts exhibited a well-spread morphology with filopodia attached to the nanoporous surface of the underlying AAO membranes or nanofibrous collagen networks, thus indicating a close interaction with the composites. Keratinocytes, although growing in clusters on bare and APTES-modified AAO, also adhered well on collagen-modified AAO membranes. When in contact with suspensions for 20 h, the AAO membranes successfully prevented bacteria penetration irrespective of the biochemical functionalization. In summary, both functionalization strategies have high potential to specifically control molecular signaling and cell migration to further develop alumina nanopores for wound healing.
在伤口愈合过程中，会发生一系列复杂的细胞和分子事件，这些事件受到拓扑和生化线索的控制。因此，最佳的组织修复需要具有多功能结构和生化特性的支架材料。纳米多孔阳极氧化铝 (AAO) 膜具有良好的生物相容性，同时具有可定制的纳米形貌和抗菌性能，这使它们成为伤口治疗的焦点。然而，尽管具有良好的渗透性，但这种生物惰性陶瓷纳米孔不能主动促进细胞生长，因为它们缺乏生化线索来支持特定的配体-受体相互作用。因此，我们通过用 (3-氨基丙基)三乙氧基硅烷 (APTES) 硅烷化来修饰 AAO 纳米孔的生化特征，用胶原纳米纤维或氨基提供，设计了一种可渗透的支架材料，可进一步促进细胞黏附。活力测定表明，3T3 成纤维细胞和 HaCaT 角质形成细胞在裸 AAO 和硅烷化 AAO 孔上的代谢活性与玻璃对照物相似，直到 72 小时。有趣的是，两种细胞类型在具有胶原纳米纤维的 AAO 上的增殖都减少了。然而，扫描电子显微镜和荧光显微镜显示，3T3 成纤维细胞表现出良好的伸展形态，有丝状伪足附着在下面 AAO 膜的纳米多孔表面或纤维状胶原网络上，这表明与复合材料有密切的相互作用。角质形成细胞虽然在裸 AAO 和 APTES 修饰的 AAO 上呈簇状生长，但也能很好地黏附在胶原修饰的 AAO 膜上。当与悬浮液接触 20 小时时，AAO 膜成功地阻止了细菌渗透，无论生化功能化如何。总之，这两种功能化策略都具有很大的潜力来特异性地控制分子信号和细胞迁移，以进一步开发用于伤口愈合的氧化铝纳米孔。
