Berthelot Ryan, Variola Fabio
Faculty of Engineering, Department of Mechanical Engineering, University of Ottawa, Canada.
Ottawa-Carleton Institute for Biomedical Engineering (OCIBME), Ottawa, Canada.
Biomater Sci. 2025 Feb 11;13(4):946-968. doi: 10.1039/d4bm00792a.
Titanium nanotubular surfaces have been extensively studied for their potential use in biomedical implants due to their ability to promote relevant phenomena associated with osseointegration, among other functions. However, despite the large body of literature on the subject, potential synergistic/antagonistic effects resulting from the combined influence of environmental variables and nanotopographical cues remain poorly investigated. Specifically, it is still unclear whether the nanotube-induced variations in cellular activity are preserved across different biochemical contexts. To bridge this gap, this study systematically evaluates the combined influence of nanotopographical cues and environmental factors on human MG63 osteoblastic cells. To this end, we capitalized on a triphasic anodization protocol to create nanostructured surfaces characterized by an average nanotube inner diameter of 25 nm (NT1) and 82 nm (NT2), as well as a two-tiered honeycomb (HC) architecture. A variable glucose content was chosen as the environmental modifier due to its well-known ability to affect specific functions of MG63 cells. Alkaline phosphatase (ALP), viability/metabolic activity and proliferation were quantified to identify the suitable preconditioning window required for dictating a change in behaviour without significantly damaging cells. Successively, a combination of immunofluorescence, colorimetric assays, live cell imaging and western blots quantified viability/metabolic activity and cell proliferation, migration and differentiation as a function of the combined effects exerted by the nanostructured substrates and the glucose content. To achieve a thorough understanding of MG63 cell adaptation and response, a comparative analysis table that includes and systematically cross-analyzes all variables from this study was used for interpretation and discussion of the results. Taken together, we have demonstrated that all surfaces mitigate the negative effects of high glucose. However, nanotubular topographies, particularly NT2, elicit a more beneficial outcome in high glucose in respect to untreated titanium. In addition, while NT1 surfaces are associated with the most stable cellular response across varying glucose levels, the NT2 and HC substrates exhibit the strongest enhancement of cell migration, viability/metabolism and differentiation. Moreover, shorter-term processes such as adhesion and proliferation are favored on untreated titanium, while anodized samples support later-term events. Lastly, the role of anodized surfaces is dominant over the effects of environmental glucose, underscoring the importance of carefully considering nanoscale surface features in the design and development of cell-instructive titanium surfaces.
由于钛纳米管表面具有促进与骨整合相关现象等多种功能的能力，因此已被广泛研究用于生物医学植入物。然而，尽管关于该主题的文献众多，但环境变量和纳米拓扑线索的综合影响所产生的潜在协同/拮抗作用仍研究不足。具体而言，尚不清楚纳米管诱导的细胞活性变化在不同生化环境中是否得以保留。为填补这一空白，本研究系统评估了纳米拓扑线索和环境因素对人MG63成骨细胞的综合影响。为此，我们利用三相阳极氧化方案制备了纳米结构表面，其特征在于平均纳米管内径为25纳米（NT1）和82纳米（NT2），以及两层蜂窝状（HC）结构。由于葡萄糖众所周知的影响MG63细胞特定功能的能力，因此选择可变葡萄糖含量作为环境调节剂。对碱性磷酸酶（ALP）、活力/代谢活性和增殖进行定量，以确定在不显著损伤细胞的情况下决定行为变化所需的合适预处理窗口。随后，通过免疫荧光、比色测定、活细胞成像和蛋白质印迹的组合，将活力/代谢活性以及细胞增殖、迁移和分化定量为纳米结构底物和葡萄糖含量共同作用的函数。为全面了解MG63细胞的适应性和反应，使用了一个包含并系统交叉分析本研究所有变量的比较分析表来解释和讨论结果。综上所述，我们证明了所有表面都减轻了高葡萄糖的负面影响。然而，纳米管拓扑结构，特别是NT2，在高葡萄糖环境中相对于未处理的钛产生了更有益的结果。此外，虽然NT1表面在不同葡萄糖水平下与最稳定的细胞反应相关，但NT2和HC底物表现出对细胞迁移、活力/代谢和分化最强的增强作用。此外，未处理的钛有利于诸如黏附和增殖等短期过程，而阳极氧化样品则支持后期事件。最后，阳极氧化表面的作用比环境葡萄糖的影响更占主导地位，这突出了在设计和开发具有细胞指导作用钛表面时仔细考虑纳米级表面特征的重要性。
