Biofilm Formation and Removal on Osseointegrated Implant Materials

The skin/percutaneous interface of osseointegrated (OI) implants is susceptible to infection, which can be devastating to patients causing excess pain, increased morbidity, and may require implant removal. Novel distal femoral OI implants with binary nitride coatings have been developed in Europe with little physiological modeling to collect microbiological evidence of resistance to bacterial attachment. This in vitro study evaluated a Ti-6Al-4V alloy coated with TiNbN and treated with low plasticity burnishing (LPB) to assess attachment and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) under conditions that modeled a physiological environment. Washability of the material was also assessed and compared to standard Ti-6Al-4V alloy materials with a polished (“Color Buff”) or non-polished finish (“Satin Finish”). It was hypothesized that TiNbN/LPB treatments would resist bacterial adhesion and biofilm formation to a greater degree than the other two materials, and also have a higher degree of bacterial removal following a clinically-relevant wash regimen. Material types were exposed to a constant flow of Brain Heart Infusion Broth containing MRSA and were analyzed using bacterial quantification, surface coverage analysis, and SEM imaging. Quantification data showed no difference in bacterial attachment amongst the varying material types, and the wash regimen likewise did not result in significant differences. Surface coverage and SEM analysis confirmed results. The wash regimen led to a reduction of approximately 3 log10 reduction in bacteria for all material types. Though the results did not support the hypothesis that a TiNbN coating/LPB treatment might resist bacterial attachment/biofilm formation to a greater degree than other alloys, or have less bacteria after cleaning, results did support the potential importance of a daily wound-hygiene regimen at the skin/implant interface OI materials. This data set included all the bacterial quantification from this study.

骨整合（osseointegrated, OI）植入物的皮肤/经皮界面易受感染，此类感染会给患者带来剧烈疼痛、加重并发症负担，甚至可能需要取出植入物，后果极为严重。欧洲已研发出带有二元氮化物涂层的新型股骨远端骨整合植入物，但相关生理学建模及细菌附着抗性的微生物学证据收集工作仍较为匮乏。本体外研究评估了经TiNbN涂层处理并结合低塑性抛光（low plasticity burnishing, LPB）的Ti-6Al-4V合金，在模拟生理环境的条件下，耐甲氧西林金黄色葡萄球菌（methicillin-resistant Staphylococcus aureus, MRSA）在其表面的附着与生物膜形成情况。同时评估了该材料的可清洗性能，并与表面经抛光（"Color Buff"）或未抛光（"Satin Finish"）的标准Ti-6Al-4V合金材料进行对比。本研究提出如下假说：TiNbN涂层结合LPB处理的材料，相比另外两种材料，能更有效地抵抗细菌黏附与生物膜形成，且在经过临床相关的清洗方案后，细菌清除率更高。将各材料组置于持续流动的含MRSA脑心浸液肉汤中，通过细菌定量分析、表面覆盖度分析及扫描电子显微镜（SEM）成像进行检测。定量检测结果显示，不同材料组的细菌附着量无显著差异，清洗方案同样未带来显著的细菌清除差异。表面覆盖度分析与SEM成像结果验证了上述结论。所有材料组经清洗方案处理后，细菌载量均降低约3 log₁₀。尽管本研究结果未支持“TiNbN涂层结合LPB处理可更有效地抵抗细菌附着与生物膜形成，或清洗后残留细菌更少”的假说，但结果证实了皮肤/植入物界面的日常伤口护理方案对骨整合材料的潜在重要性。本数据集包含了本研究中所有的细菌定量检测数据。