Unlike the native surface of the implant material (Ti6Al4V), oxidation with H${}_2$O${}_2$ leads to increased binding of the effective antimicrobial agent poly(hexamethylene) biguanide [PHMB]. However, treating with NaOH instead results in an even higher PHMB mass coverage. After oxidation with H${}_2$O${}_2$, strong differences in the PHMB adsorption capability between polished and corundum-blasted surfaces appear, indicating a roughness dependence. After NaOH treatment, no such effect was observed. The wetting properties of specimens treated with either H${}_2$O${}_2$ or NaOH prior to PHMB exposure clearly varied. To unravel the nature of this interaction, widespread in silico and in vitro experiments were performed. Methods: By X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurements and MD simulations, we characterized the interplay between the polycationic antimicrobial agent and the implant surface. A theoretical model for PHMB micelles is tested for its wetting properties and compared to carbon contaminated TiO${}_2$. In addition, quantitation of anionic functional group equivalents, the binding properties of PHMB with blocked amino end-group, and the ability to bind chlorhexidine digluconate (CHG) were investigated. Ultimately, the capability of osteoblasts to build calcium apatite, and the activity of alkaline phosphatase on PHMB coated specimens, were determined. Results: Simulated water contact angles on carbon contaminated TiO${}_2$ surfaces and PHMB micelle models reveal little influence of PHMB on the wetting properties and point out the major influence of remaining and recovering contamination from ambient air. Testing PHMB adsorption beyond the critical micelle concentration and subsequent staining reveals an island-like pattern with H${}_2$O${}_2$ as compared to an evenly modified surface with NaOH. Both CHG and PHMB, with blocked amino end groups, were adsorbed on the treated surfaces, thus negating the significant influence of PHMB’s terminal groups. The ability of osteoblasts to produce calcium apatite and alkaline phosphatase is not negatively impaired for PHMB mass coverages up to 8$\mathrm{g}$/specimen. Conclusion: Differences in PHMB adsorption are triggered by the number of anionic groups and carbon contaminants, both of which depend on the specimen pre-treatment. With more PHMB covering, the implant surface is protected against the capture of new contamination from the ambient air, thus building a robust antimicrobial and biocompatible surface coating.

中文翻译：

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通过 NaOH 处理改善抗菌剂聚（六亚甲基）双胍在 Ti-Al-V 合金上的吸附以及质量覆盖和污染对细胞相容性的影响

与植入材料的天然表面 (Ti6Al4V) 不同，用 H 氧化${}_2$哦${}_2$导致有效抗菌剂聚（六亚甲基）双胍 [PHMB] 的结合增加。然而，用 NaOH 处理反而会导致更高的 PHMB 质量覆盖率。用H氧化后${}_2$哦${}_2$，抛光和刚玉喷砂表面之间的 PHMB 吸附能力出现很大差异，表明粗糙度依赖性。NaOH 处理后，没有观察到这种效果。用 H 处理的试样的润湿性能${}_2$哦${}_2$PHMB 暴露前的 NaOH 或 NaOH 明显不同。为了解开这种相互作用的本质，进行了广泛的计算机和体外实验。方法：通过 X 射线光电子能谱、扫描电子显微镜、水接触角测量和 MD 模拟，我们表征了聚阳离子抗菌剂和植入物表面之间的相互作用。测试了 PHMB 胶束的理论模型的润湿性能，并与碳污染的 TiO2 进行了比较${}_2$. 此外，还研究了阴离子官能团等价物的定量、PHMB 与封闭氨基端基的结合特性以及结合二葡萄糖酸氯己定 (CHG) 的能力。最终，确定了成骨细胞构建钙磷灰石的能力，以及碱性磷酸酶对 PHMB 涂层标本的活性。结果：在碳污染的二氧化钛上模拟水接触角${}_2$表面和 PHMB 胶束模型显示 PHMB 对润湿性能的影响很小，并指出了从环境空气中残留和回收污染物的主要影响。测试超过临界胶束浓度的 PHMB 吸附和随后的染色显示出具有 H 的岛状图案${}_2$哦${}_2$与用 NaOH 均匀改性的表面相比。具有封闭氨基端基的 CHG 和 PHMB 都吸附在处理过的表面上，从而消除了 PHMB 端基的显着影响。对于高达 8 的 PHMB 质量覆盖，成骨细胞产生钙磷灰石和碱性磷酸酶的能力不会受到负面影响$\mathrm{G}$/标本。结论：PHMB 吸附的差异是由阴离子基团和碳污染物的数量引发的，这两者都取决于样品的预处理。有了更多的 PHMB 覆盖层，植入物表面可以防止从环境空气中捕获新的污染物，从而构建强大的抗菌和生物相容性表面涂层。