Multidrug resistance of bacteria has led to the invalidation of traditional therapies using antibiotics and has formed a huge threat to human health. Therefore, promising antibacterial therapies are urgently demanded. Nitric oxide (NO) has attracted much attention in the field of antibacterial agents, and novel antibacterial materials based on NO are being developed rapidly. In this work, we first proposed a carbon dot (CDs)-based and NO-releasing platform for antibacterial application. Here, the chitosan-graft-poly(amidoamine) dendrimer (CPA) was used to synthesize fluorescent CDs via one-step hydrothermal carbonization, and CPA-CDs were successfully prepared, followed by loading NO with the formation of N-diazeniumdiolate (NONOate). The resultant CPA-CDs/NONOate displayed 3.5 times the NO content of the CPA copolymer. Due to their stable photoluminescence, the super-resolution bacterial imaging ability of CPA-CDs/NONOate was observed. Moreover, excellent in vitro and in vivo antibacterial effects were demonstrated against Pseudomonas aeruginosa, where bacterial viability and biofilm were significantly reduced. Further, in vivo assays proved the theranostic activity of CPA-CDs/NONOate in curing rats’ wounds with serious bacterial infection. Importantly, these NO-releasing CDs possessed outstanding in vivo and in vitro biocompatibilities. This study provided a multifunctional strategy, providing a foundation for fast bacterial detection and precise antibacterial treatments.

中文翻译：

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具有高一氧化氮有效载荷的荧光碳点，可实现有效的抗菌活性和细菌成像

细菌的多药耐药性导致使用抗生素的传统疗法失效，对人类健康形成巨大威胁。因此，迫切需要有前景的抗菌疗法。一氧化氮（NO）在抗菌剂领域备受关注，基于NO的新型抗菌材料正在迅速发展。在这项工作中，我们首先提出了一种基于碳点 (CDs) 的 NO 释放平台，用于抗菌应用。在这里，壳聚糖接枝聚（酰胺胺）树枝状大分子（CPA）用于通过一步水热碳化合成荧光CDs ，成功制备了CPA-CDs，然后负载NO并形成N-diazeniumdiolate (NONOate)。所得的 CPA-CDs/NONOate 显示出是 CPA 共聚物中 NO 含量的 3.5 倍。由于其稳定的光致发光，观察到 CPA-CDs/NONOate 的超分辨率细菌成像能力。此外，对铜绿假单胞菌具有出色的体外和体内抗菌作用，其中细菌活力和生物膜显着降低。此外，体内试验证明了 CPA-CDs/NONOate 在治疗患有严重细菌感染的大鼠伤口方面的治疗诊断活性。重要的是，这些释放 NO 的 CD在体内和体外都具有出色的表现。生物相容性。该研究提供了一种多功能策略，为快速细菌检测和精确抗菌治疗提供了基础。