As the barrier between the human body and the outside world, the skin is vulnerable to pathogenic microorganisms, especially when suffering from skin injuries such as burns. Staphylococcus aureus remains the most common type of bacteria that infects humans, and the surging drug resistance poses a major threat to the treatment of these infections. Here we report the development of antibacterial photodynamic peptides (APPs) that are constructed based on the covalent conjugation of an antibacterial peptide and the photosensitizer chlorin e6 (Ce6). Peptide conjugation significantly increases the photo-stability of Ce6, while retaining its ROS generation capability under photo-irradiation. The APPs combine the antibacterial activity of the peptide and the photodynamic therapy of Ce6, and under the assistance of mild laser irradiation, can eradicate bacterial infection and inhibit the formation of bacterial biofilms ex vivo. One of the APPs, (GKRWWKWWRR)₂KGGK(Ce6)G, AMP₂-Ce6, with Ce6 conjugated with the dimeric peptide, showed exceptional antibacterial activity with an MIC₉₀ value around 3.2 μM without photo-irradiation and <0.1 μM with short light treatment. Supported by a hydrogel matrix composed of gelatin and recombinant human collagen III protein (rhCol III) mimicking the extracellular matrix of skin cells, AMP₂-Ce6 efficiently accelerated the healing rate of wounds and improved the quality of wound healing in mice infected with Staphylococcus aureus. Altogether, here we report the development of antibacterial photodynamic peptides, which together with a regenerative matrix material exhibit an added effect against staphylococcal skin infection. This composite material holds promise as a new type of wound dressing material for skin infection and wound healing.

中文翻译：

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用于葡萄球菌皮肤感染的抗菌光动力肽

作为人体与外界之间的屏障，皮肤容易受到病原微生物的侵害，尤其是在遭受皮肤灼伤等灼伤时。金黄色葡萄球菌细菌仍然是感染人类的​​最常见细菌，耐药性的急剧上升对这些感染的治疗构成了重大威胁。在这里，我们报告了基于抗菌肽和光敏剂二氢卟酚e6（Ce6）的共价结合而构建的抗菌光动力肽（APPs）的开发。肽结合显着提高了Ce6的光稳定性，同时在光辐照下仍保持其ROS生成能力。该APP结合了该肽的抗菌活性和Ce6的光动力疗法，并在轻度激光照射的辅助下，可以根除细菌感染并抑制离体细菌生物膜的形成。其中一个应用程序（GKRWWKWWRR）₂ KGGK（Ce6）G，AMP具有Ce6与二聚体肽缀合的_2- Ce6表现出卓越的抗菌活性，无光照射的MIC ₉₀值约为3.2μM，短光处理的MIC ₉₀值为<0.1μM。在明胶和模仿皮肤细胞胞外基质的重组人胶原蛋白III蛋白（rhCol III）组成的水凝胶基质的支持下，AMP ₂ -Ce6有效地加速了伤口的愈合速度并改善了感染金黄色葡萄球菌的小鼠的伤口愈合质量。总而言之，我们在此报告了抗菌光动力肽的开发，该肽与再生基质材料一起显示出对抗葡萄球菌皮肤感染的附加作用。这种复合材料有望作为一种新型的伤口敷料用于皮肤感染和伤口愈合。