There is a consensus that the prevention of wound infection should be achieved in the following ways: (1) closing the wound to protect it from extra infection; (2) an antibacterial agent that could kill endogenous bacteria. However, existing bulk two-dimensional antibacterial materials show inefficient adhesion to wounds with complex morphology and thus cause the prevention of wound closure. Reducing the thickness of bulk two-dimensional materials to less than 100 nanometres endows them with great flexibility, which could allow them to adhere to wounds with complex morphology by only physical adhesion. Herein, a broad-spectrum and efficient antimicrobial peptide (AMP) was introduced to biocompatible methacrylated gelatine (GelMA) with multiple modification sites, which served as an inner antibacterial layer. After being combined with a biodegradable and good mechanical poly-l-lactide (PLLA) outer layer through plasma-treatment-assisted spin coating, we finally constructed bilayered antibacterial nanosheets with a thickness of approximately 80 nm. These bilayered nanosheets possess good adhesion to surfaces with complex topography and thus achieve better wound closure than other bulk two-dimensional materials. Moreover, this AMP-grafted conjugation shows minimal cytotoxicity compared with Ag⁺ antibacterial agents, and the antibacterial rate of nanosheets is dependent on the graft rate of AMP. We suggest that this bilayered antibacterial nanosheet might be an advanced anti-infection dressing for wound treatment in clinical settings.

中文翻译：

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用于复杂形貌伤口抗感染的双层纳米片

人们普遍认为应通过以下方式来预防伤口感染：（1）闭合伤口以保护其免受额外感染；（2）可以杀死内源性细菌的抗菌剂。然而，现有的散装二维抗菌材料对具有复杂形态的伤口显示出低效的粘附性，因此导致伤口闭合的预防。将二维大块材料的厚度减小到不到100纳米，可以使它们具有很大的柔韧性，这可以使它们仅通过物理粘附即可粘附具有复杂形态的伤口。在此，将广谱和有效的抗菌肽（AMP）引入具有多个修饰位点的生物相容性甲基丙烯酸明胶（GelMA），用作内部抗菌层。在通过等离子处理辅助旋涂与可生物降解的良好机械聚乳酸（PLLA）外层结合后，我们最终构建了厚度约为80 nm的双层抗菌纳米片。这些双层纳米片对具有复杂形貌的表面具有良好的附着力，因此与其他块状二维材料相比，伤口闭合效果更好。此外，与Ag相比，这种AMP嫁接的缀合物显示出最小的细胞毒性⁺抗菌剂，纳米片的抗菌率取决于AMP的接枝率。我们建议这种双层抗菌纳米片可能是用于临床环境中伤口治疗的高级抗感染敷料。