Biomedical associated infections (BAI) are difficult to treat and may even lead to amputation and death, especially after the emergence of drug-resistant bacteria. The aim of this study was to harness the potential synergistic effects of multiple bactericidal agents to endow polyetheretherketone (PEEK) with the ability of achieving full eradication of planktonic and adherent bacteria while maintaining acceptable biocompatibility. In this work, a mussel inspired, silver nanoparticles (AgNPs) incorporated silk fibroin (SF)/gentamicin sulfate (GS) coating was constructed upon porous PEEK surface. The obtained coating greatly enhanced the bactericidal efficiency to Gram-positive bacteria and Gram-negative bacteria. The number of bacteria survived in the culture medium after treated with this coating was 10⁶ fold lower than that survived after treated with PEEK sample, while the number of viable bacteria adhered to this coating was 10⁵ lower than that adhered to PEEK sample. Furthermore, release of Ag⁺ and GS increased with decreasing pH, indicating great potential of this coating to be a “smart” bacteria-triggered self-defensive coating. Meanwhile, this functional coating shows favorable cytocompatibility and osteogenic ability. The mechanism behind this dual function is also partially revealed. Expectedly, this “smart” dual function coating can give a promise for PEEK to become a solution to increasingly deteriorated BAI.

Statement of significance

In this study, a mussel inspired, silver nanoparticles (AgNPs) incorporated silk fibroin (SF)/gentamicin sulfate (GS) coating was constructed upon porous polyetheretherketone (PEEK) surface. This design was aimed to provide a solution to the increasingly deteriorated biomedical associated infections (BAI). Actually, this design endowed PEEK with dual function: bacteria-triggered synergistic bactericidal effect and improved osteogenic ability. The combination of silver and GS exhibited synergistic bacteria killing effect on both Gram-positive and Gram-negative bacteria, which showed 10⁶ times higher in releasing-killing and 10⁵ times higher in anti-adhesion than that of untreated PEEK. Furthermore, release of bactericidal agents increased with decreasing pH, indicating great potential of this coating to be a bacteria-triggered self-defensive coating. More interestingly, this study revealed the mechanism of synergistic effect between silver and GS.

中文翻译：

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赋予聚醚醚酮协同杀菌作用并提高成骨能力

生物医学相关感染（BAI）难以治疗，甚至可能导致截肢和死亡，尤其是在耐药细菌出现后。这项研究的目的是利用多种杀菌剂的潜在协同作用，赋予聚醚醚酮（PEEK）以完全消除浮游细菌和附着细菌的能力，同时保持可接受的生物相容性。在这项工作中，在多孔PEEK表面上构建了贻贝启发的，掺有丝素蛋白（SF）/硫酸庆大霉素（GS）涂层的银纳米颗粒（AgNPs）。所获得的涂层极大地提高了对革兰氏阳性细菌和革兰氏阴性细菌的杀菌效率。用该涂层处理后在培养基中存活的细菌数为10 ⁶比用PEEK样品处理后存活的细菌低1倍，而附着在该涂层上的活细菌的数量比附着在PEEK样品上的细菌少10 ⁵。此外，随着pH值的降低，Ag ⁺和GS的释放增加，表明该涂层具有成为“智能”细菌触发的自防御涂层的巨大潜力。同时，该功能涂层显示出良好的细胞相容性和成骨能力。双重功能背后的机制也被部分揭示。可以预期，这种“智能”双功能涂层可以为PEEK成为日益恶化的BAI的解决方案提供希望。

重要声明

在这项研究中，在多孔聚醚醚酮（PEEK）表面上构建了贻贝启发的，掺有丝素蛋白（SF）/硫酸庆大霉素（GS）的银纳米颗粒（AgNPs）涂层。该设计旨在为日益恶化的生物医学相关感染（BAI）提供解决方案。实际上，这种设计赋予了PEEK双重功能：细菌触发的协同杀菌作用和提高的成骨能力。银和GS的组合表现出协同的细菌上革兰氏阳性和革兰氏阴性细菌，其显示10杀灭作用⁶更高倍于释放杀灭和10 ⁵抗粘连性是未经处理的PEEK的三倍。此外，杀菌剂的释放随pH值的降低而增加，表明该涂层具有很大的潜力成为细菌触发的自卫涂层。更有趣的是，这项研究揭示了银与GS之间协同作用的机制。