Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av. Limeira, 901, Piracicaba, São Paulo 13414-903, Brazil.
Institute of Science and Technology, São Paulo State University (UNESP), Av. Três de Março, 511, Sorocaba, São Paulo 18087-180, Brazil.
Mater Sci Eng C Mater Biol Appl. 2020 May;110:110657. doi: 10.1016/j.msec.2020.110657. Epub 2020 Jan 25.
Photofunctionalization mediated by ultraviolet (UV) rays changes the physico-chemical characteristics of titanium (Ti) and improves the biological activity of dental implants. However, the role of UV-mediated photofunctionalization of biofunctional Ti surfaces on the antimicrobial and photocatalytic activity remains unknown and was investigated in this study. Commercially pure titanium (cpTi) discs were divided into four groups: (1) machined samples without UV light application [cpTi UV-]; (2) plasma electrolytic oxidation (PEO) treated samples without UV light application [PEO UV-]; (3) machined samples with UV light application [cpTi UV+]; and (4) PEO-treated samples with UV light application [PEO UV+]. The surfaces were characterized according to their morphology, roughness, crystalline phase, chemical composition and wettability. The photocatalytic activity and proteins adsorption were measured. For the microbiological assay, Streptococcus sanguinis was grown on the disc surfaces for 1 h and 6 h, and the colony forming units and bacterial organization were evaluated. In addition, to confirm the non-cytotoxic effect of PEO UV +, human gingival fibroblast (HGF) cells were cultured in a monolayer onto each material surface and the cells viability and proliferation evaluated by a fluorescent cell staining method. PEO treatment increased the Ti surface roughness and wettability (p < 0.05). Photofunctionalization reduced the hydrocarbon concentration and enhanced human blood plasma proteins and albumin adsorption mainly for the PEO-treated surface (p < 0.05). PEO UV+ also maintained higher wettability values for a longer period and provided microbial reduction at 1 h of bacterial adhesion (p = 0.012 vs. PEO UV-). Photofunctionalization did not increase the photocatalytic activity of Ti (p > 0.05). Confocal microscopy analyses demonstrated that PEO UV+ had no cell damage effect on HGF cells growth even after 24 h of incubation. The photofunctionalization of a biofunctional PEO coating seems to be a promising alternative for dental implants as it increases blood plasma proteins adsorption, reduces initial bacterial adhesion and presents no cytotoxicity effect.
紫外线（UV）介导的光功能化改变了钛（Ti）的物理化学特性，并提高了牙科植入物的生物活性。然而，生物功能 Ti 表面的 UV 介导光功能化在抗菌和光催化活性方面的作用尚不清楚，本研究对此进行了探讨。将商用纯钛（cpTi）圆盘分为四组：（1）未经 UV 光应用的机械加工样品[cpTi UV-]；（2）未经 UV 光应用的等离子体电解氧化（PEO）处理样品[PEO UV-]；（3）经 UV 光应用的机械加工样品[cpTi UV+]；和（4）经 UV 光应用的 PEO 处理样品[PEO UV+]。根据形貌、粗糙度、晶体相、化学成分和润湿性对表面进行了表征。测量了光催化活性和蛋白质吸附。对于微生物分析，将血链球菌在圆盘表面生长 1 小时和 6 小时，并评估菌落形成单位和细菌组织。此外，为了确认 PEO UV+的非细胞毒性作用，将人牙龈成纤维细胞（HGF）单层培养在各材料表面，并通过荧光细胞染色法评估细胞活力和增殖。PEO 处理增加了 Ti 表面的粗糙度和润湿性（p<0.05）。光功能化降低了碳氢化合物浓度，并增强了人血浆蛋白质和白蛋白的吸附，主要是对 PEO 处理的表面（p<0.05）。PEO UV+还保持了较长时间的高润湿性值，并在 1 小时的细菌黏附时提供了微生物减少（p=0.012 与 PEO UV-相比）。光功能化没有增加 Ti 的光催化活性（p>0.05）。共聚焦显微镜分析表明，即使孵育 24 小时后，PEO UV+对 HGF 细胞生长也没有细胞损伤作用。生物功能 PEO 涂层的光功能化似乎是牙科植入物的一种有前途的替代方法，因为它增加了血浆蛋白质的吸附，减少了初始细菌黏附，并且没有细胞毒性作用。
