For biomedical applications, a number of ceramic coatings have been investigated, but the interactions with the components of living system remain unexplored for oxycarbonitride coatings. While addressing this aspect, the present study aims to provide an understanding of the biocompatibility of novel SiC_xN_yO_z coatings that could validate the hypothesis that such coatings may not only enhance the cell–material interaction by re-endothelialization but also can help to reduce bacterial adhesion and activation of blood cells. This work reports the physicochemical properties, hemocompatibility, endothelialization, and antibacterial properties of novel amorphous SiC_xN_yO_z coatings deposited on commercial pure titanium (Ti) by radiofrequency (RF) magnetron sputtering at varied nitrogen (N₂) flow rates. A comparison is made with diamond-like carbon (DLC) coatings, which are clinically used. The surface roughness, surface wettability, nanoscale hardness, and surface energy of SiC_xN_yO_z coatings were found to be dependent on the nitrogen (N₂) flow rate. Importantly, the as-deposited SiC_xN_yO_z coatings exhibited much better nanoscale hardness and scratch resistance than DLC coatings. Furthermore, Raman spectroscopy analysis of the SiC_xN_yO_z coating deposited on Ti showed a change in the graphitic/disordered carbon content. Cytocompatibility and hemocompatibility properties of the as-deposited SiC_xN_yO_z coating were evaluated using the Mus musculus lymphoid endothelial cell line (SVEC4-10) and rabbit blood in vitro. WST-1 assay analysis showed that these coatings, when compared to DLC, exhibited a better proliferation of endothelial cells, which can potentially result in improved surface endothelialization. Furthermore, qualitative and quantitative analyses of immunofluorescence images revealed a dense cellular layer of SVEC4-10 on SiC_xN_yO_z coatings, deposited at 15 and 30 sccm nitrogen flow rates. As far as compatibility with rabbit blood is concerned, the hemolysis of the SiC_xN_yO_z coatings was less than 4%, with slightly lower values for coatings deposited without N₂ flow. The SiC_xN_yO_z coatings support less platelet adhesion and aggregation, with no signature of morphological deformation, as compared to the uncoated titanium substrate or DLC coatings. Furthermore, SiC_xN_yO_z coatings were also found to be effectively extending the blood coagulation time for a period of 60 min. The antimicrobial study of as-deposited SiC_xN_yO_z coatings on E. coli and S. aureus bacteria revealed the effective inhibition of bacterial proliferation after 24 h of culture. An attempt has been made to explain the cyto- and hemocompatibility properties with antimicrobial efficacy of coatings in terms of the variation in the coating composition and surface energy. Taken together, we conclude that SiC_1.3N_0.76O_0.87 coating having a roughness of 17 nm and a surface free energy of 54.0 ± 0.7 mN/m can exhibit the best combination of hardness, elastic modulus, scratch resistance, cytocompatibility, hemocompatibility, and bactericidal properties.

中文翻译：

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SiC _x N _y O _z涂层增强内皮化和杀菌活性并减少血细胞活化

对于生物医学应用，已经研究了许多陶瓷涂层，但是对于碳氧氮化物涂层，仍未探索与生物系统各组分的相互作用。在解决此问题的同时，本研究旨在提供对新型SiC _x N _y O _z涂层的生物相容性的理解，该涂层可以验证以下假设：此类涂层不仅可以通过重新内皮化增强细胞与材料的相互作用，而且可以帮助减少细菌粘附和激活血细胞。这项工作报告了新型无定形SiC _x N _y O _z的理化特性，血液相容性，内皮化和抗菌特性通过射频（RF）磁控溅射在变化的氮气（N ₂）流速下沉积在商用纯钛（Ti）上的涂层。对临床上使用的类金刚石碳（DLC）涂层进行了比较。发现SiC _x N _y O _z涂层的表面粗糙度，表面润湿性，纳米级硬度和表面能取决于氮（N ₂）流量。重要的是，沉积后的SiC _x N _y O _z涂层比DLC涂层具有更好的纳米级硬度和耐刮擦性。此外，SiC _x N _y O _z的拉曼光谱分析沉积在Ti上的涂层显示出石墨/无序碳含量的变化。使用家鼠小肠淋巴样内皮细胞系（SVEC4-10）和兔血在体外评估沉积的SiC _x N _y O _z涂层的细胞相容性和血液相容性。WST-1分析分析表明，与DLC相比，这些涂层具有更好的内皮细胞增殖能力，这可能会导致表面内皮化的改善。此外，对免疫荧光图像的定性和定量分析表明，SiC _x N _y O _z上有一层致密的SVEC4-10细胞层。涂层，以15和30 sccm的氮气流速沉积。就与兔血的相容性而言，SiC _x N _y O _z涂层的溶血度小于4％，没有N ₂流动时沉积的涂层的溶度略低。与未涂覆的钛基材或DLC涂层相比，SiC _x N _y O _z涂层支持较少的血小板粘附和聚集，没有形态学变形的迹象。此外，SiC _x N _y O _z还发现涂层可有效延长凝血时间60分钟。对在大肠杆菌和金黄色葡萄球菌上沉积的SiC _x N _y O _z涂层进行的抗菌研究表明，培养24小时后，有效抑制了细菌的增殖。已经尝试根据涂层组成和表面能的变化来解释具有抗菌功效的涂层的细胞和血液相容性。综上所述，我们得出的结论是SiC _1.3 N _0.76 O _0.87 粗糙度为17 nm，表面自由能为54.0±0.7 mN / m的涂层可以显示硬度，弹性模量，耐刮擦性，细胞相容性，血液相容性和杀菌性能的最佳组合。