Titanium and its alloys have been widely used in orthopedic and dental implants because of their excellent properties. However, implant failures still occur due to implant-associated bacterial infections. Therefore, proper surface modification of titanium and its alloys is necessary. In this work, commercial pure titanium plates were modified with graphene oxide (GO) which was used to load minocycline hydrochloride. Gram-positive Staphylococcus aureus (S. aureus) and Streptococcus mutans (S. mutans) and Gram-negative Escherichia coli (E. coli) were used to investigate the antibacterial activity of the samples. Human gingival fibroblast (HGF) cells were applied to assess the cytocompatibility of the various samples. To investigate cell adhesion and cell surface coverage in the presence of bacteria, the coculture of HGF cells and S. aureus was performed. The results indicated that the GO-modified titanium surface could inhibit the growth of the bacteria which had direct contact with GO, while it could not affect the bacteria without direct contact of GO. Minocycline hydrochloride on the GO-modified titanium surface (M@GO-Ti) showed a slow release behavior and exhibited excellent antibacterial activity with the synergistic effect of contact-killing and release-killing by GO and minocycline hydrochloride, respectively. In the coculture process with the presence of S. aureus, HGF cells on M@GO-Ti demonstrated the best cell viability and cell surface coverage among all the samples.

中文翻译：

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氧化石墨烯负载在钛上的盐酸米诺环素：出色的抗菌平台，具有接触杀灭和释放杀灭的协同作用

钛及其合金由于其优异的性能已被广泛用于整形外科和牙科植入物中。但是，由于植入物相关的细菌感染，仍然会发生植入物失败。因此，必须对钛及其合金进行适当的表面改性。在这项工作中，用氧化石墨烯（GO）修饰了商用纯钛板，该氧化石墨烯用于加载盐酸米诺环素。革兰氏阳性金黄色葡萄球菌（S. aureus）和变形链球菌（S. mutans）和革兰氏阴性大肠杆菌（E. coli））用于研究样品的抗菌活性。将人牙龈成纤维细胞（HGF）细胞用于评估各种样品的细胞相容性。为了研究细菌存在下的细胞粘附和细胞表面覆盖率，HGF细胞和金黄色葡萄球菌的共培养被执行了。结果表明，GO修饰的钛表面可以抑制与GO直接接触的细菌的生长，而对没有GO直接接触的细菌不会产生影响。盐酸米诺环素在GO修饰的钛表面（M @ GO-Ti）上表现出缓慢的释放行为，并具有优异的抗菌活性，并分别具有GO和盐酸米诺环素的接触杀灭和释放杀灭的协同作用。在金黄色葡萄球菌存在下的共培养过程中，在所有样品中，M @ GO-Ti上的HGF细胞表现出最佳的细胞活力和细胞表面覆盖率。