State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, PR China; School of Mechanical Engineering, Anyang Institute of Technology, Anyang 455000, PR China.
State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, PR China; State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, PR China.
Mater Sci Eng C Mater Biol Appl. 2020 May;110:110722. doi: 10.1016/j.msec.2020.110722. Epub 2020 Feb 3.
It is known that introducing a porous ceramic coating on titanium (Ti) implant surface fabricated by micro-arc oxidation (MAO) could enhance the differentiation of osteoblasts. However, the osteogenic capacity of MAO-fabricated coating still remains unknown when immune cells especially macrophages are involved. The influence of the inflammatory microenvironment and the co-influence of the inflammatory microenvironment and surface characteristics of MAO-fabricated coating on osteoblast response need to be explored. In this study, a new in vitro cell culture strategy is proposed by mimicking the biological events happened after implantation based on the recruitment of osteoblasts to biomaterial surfaces to investigate biological performances of MAO-modified Ti surface. It is found that macrophages grown on MAO-modified Ti surface were switched to M1-like phenotype, evidenced by the promoted expressions of inflammatory genes (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β) and production of pro-inflammatory cytokine TNF-α. Moreover, the inflammatory microenvironment created by macrophage/MAO-modified Ti surface interactions could promote the collagen syntheses and matrix mineralization of osteoblast-like cells grown tissue culture plate. When osteoblasts were cultured on MAO-modified Ti surface and cultured by macrophage/MAO-modified Ti surface conditioned medium (CM), the alkaline phosphatase (ALP) activity and collagen synthesis of osteoblast-like cells were promoted. This study suggests that MAO-modified Ti surface is beneficial for osteogenesis at both stages after implantation (before and after osteoblast recruitment to biomaterial surfaces).
已知在通过微弧氧化 (MAO) 制造的钛 (Ti) 植入物表面引入多孔陶瓷涂层可以增强成骨细胞的分化。然而，当涉及免疫细胞尤其是巨噬细胞时，MAO 制造的涂层的成骨能力仍然未知。需要探索炎症微环境的影响以及炎症微环境和 MAO 制造的涂层表面特性对成骨细胞反应的共同影响。在这项研究中，提出了一种新的体外细胞培养策略，通过模拟植入后发生的生物学事件，基于成骨细胞向生物材料表面的募集来研究 MAO 改性 Ti 表面的生物学性能。研究发现，在 MAO 改性 Ti 表面上生长的巨噬细胞被转化为 M1 样表型，这表现在炎症基因（肿瘤坏死因子-α (TNF-α)、白细胞介素-6 (IL-6) 和白细胞介素-1β）的表达增强和促炎细胞因子 TNF-α 的产生。此外，巨噬细胞/MAO 改性 Ti 表面相互作用所产生的炎症微环境可以促进组织培养板上生长的成骨样细胞的胶原蛋白合成和基质矿化。当成骨细胞在 MAO 改性 Ti 表面上培养并在巨噬细胞/MAO 改性 Ti 表面条件培养基 (CM) 中培养时，成骨样细胞的碱性磷酸酶 (ALP) 活性和胶原蛋白合成得到促进。这项研究表明，MAO 改性 Ti 表面有利于植入后（在成骨细胞募集到生物材料表面之前和之后）的两个阶段的成骨。
