A near-infrared (NIR) light-triggerable thermo-sensitive hydrogel-based drug reservoir that can realize on-demand antibiotics release and hyperthermia-assisted bacterial inactivation was prepared to combat bacterial infection and promote wound healing. The drug reservoir was fabricated by mixing ciprofloxacin (Cip, a potent antibiotic)-loaded polydopamine (PDA) nanoparticles (NPs) and glycol chitosan (GC) to form an injectable hydrogel (PDA NP-Cip/GC hydrogel, abbreviated as Gel-Cip). On the one hand, the positive charge of GC and the adsorbability of PDA NPs made bacteria be readily trapped on the surface of Gel-Cip. On the other hand, the Gel-Cip exhibited minimal leakage under physiological conditions, but could boost Cip release upon NIR light irradiation. Meanwhile, NIR light irradiation could activate the photothermal PDA NPs, and the generated local hyperthermia induced the destruction of the bacterial integrity, leading to bacterial inactivation in a synergistic way. Moreover, the exceptional bacterial killing activity and outstanding wound healing ability of the system were also verified by the S. aureus-infected mouse skin defect model. Taken together, the light-activatable hydrogel-based platform allows us to release antibiotics more precisely, eliminate bacteria more effectively, and inhibit bacteria-induced infections more persistently, which will advance the development of novel antibacterial agents and strategies.

中文翻译：

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使用基于热敏水凝胶的药物库来对抗细菌感染，可释放近红外光可控的按需抗生素。

可以实现按需释放抗生素和热辅助细菌灭活的近红外（NIR）光触发热敏水凝胶基药物储库，旨在对抗细菌感染并促进伤口愈合。通过将载有环丙沙星（Cip，一种有效的抗生素）的聚多巴胺（PDA）纳米颗粒（NPs）和乙二醇壳聚糖（GC）混合以形成可注射的水凝胶（PDA NP-Cip / GC水凝胶，缩写为Gel-Cip）来制备药物储库）。一方面，GC的正电荷和PDA NPs的吸附性使细菌易于捕获在Gel-Cip的表面上。另一方面，Gel-Cip在生理条件下表现出最小的泄漏，但是在近红外光照射下可以促进Cip释放。同时，近红外光照射可以激活光热PDA NPs，并且产生的局部高温导致细菌完整性的破坏，从而以协同方式导致细菌失活。此外，金黄色葡萄球菌感染的小鼠皮肤缺损模型也证实了该系统优异的细菌杀灭活性和出色的伤口愈合能力。总之，基于光活化水凝胶的平台使我们能够更精确地释放抗生素，更有效地消除细菌，更持久地抑制细菌引起的感染，这将推动新型抗菌剂和策略的发展。金黄色葡萄球菌感染的小鼠皮肤缺损模型也证实了该系统优异的细菌杀伤活性和出色的伤口愈合能力。总之，基于光活化水凝胶的平台使我们能够更精确地释放抗生素，更有效地消除细菌，更持久地抑制细菌引起的感染，这将推动新型抗菌剂和策略的发展。金黄色葡萄球菌感染的小鼠皮肤缺损模型也证实了该系统优异的细菌杀伤活性和出色的伤口愈合能力。总之，基于光活化水凝胶的平台使我们能够更精确地释放抗生素，更有效地消除细菌，更持久地抑制细菌引起的感染，这将推动新型抗菌剂和策略的发展。