School of Biomedical Engineering, Research and Engineering Center of Biomedical Materials, Anhui Medical University, Hefei 230032, China.
School of Food and Biological Engineering, Hefei University of Technology, Hefei 230009, China.
Acta Biomater. 2022 Sep 1;149:359-372. doi: 10.1016/j.actbio.2022.06.031. Epub 2022 Jun 30.
Nanozymes are effective antibiotics that use reactive oxygen species (ROS) produced by Fenton/Fenton-like reactions to kill bacteria. However, its activity is still not satisfactory and requires large amounts of hydrogen peroxide (HO) with side effects on normal tissues. Herein, ultrasmall VC nanodots (NDs) are successfully constructed by the liquid-phase exfoliation method for photothermal-catalytic synergistic antibacterial treatment. The prepared VC NDs are horseradish peroxidase (HRP)-like nanozymes that can efficiently catalyze HO to produce a large amount of ROS. Unlike traditional HRP-like nanozymes, VC NDs can have a good catalytic effect under slightly acidic conditions (pH=5.5). Moreover, VC NDs have good near-infrared (NIR) absorption and high photothermal conversion efficiency (PTCE, 50.39%), which can be used for photothermal treatment (PTT) of bacteria. In addition, the mild photothermal effect can further enhance the HRP-like catalytic activity of VC NDs, thereby further enhancing the antibacterial performance of VC NDs. In vitro results show that VC NDs can effectively eradicate Escherichia coli (E. coli, gram-negative) and methicillin-resistant Staphylococcus aureus (MRSA, gram-positive) under laser irradiation and the presence of HO, possessing spectral antibacterial properties. More importantly, VC NDs display satisfactory therapeutic effects on wounds infected by MRSA in vivo, and their toxicity is negligible, suggesting that they may have great potential for application as powerful and safe antibacterial agents. This work presents a practical antibacterial strategy by combining PTT and catalytic therapy to achieve efficient treatment of bacteria-infected wounds. STATEMENT OF SIGNIFICANCE: (1) Ultrasmall VC NDs were prepared by the liquid-phase exfoliation method. (2) VC NDs showed good photothermal, catalytic properties. (3) VC NDs achieved satisfactory photothermal-catalytic synergistic antibacterial treatment.
纳米酶是一种有效的抗生素，它利用芬顿/类芬顿反应产生的活性氧物质（ROS）来杀死细菌。然而，其活性仍然不尽如人意，需要大量的过氧化氢（HO），并且对正常组织有副作用。在此，通过液相剥离法成功构建了用于光热-催化协同抗菌治疗的超小 VC 纳米点（NDs）。所制备的 VC NDs 是辣根过氧化物酶（HRP）样纳米酶，可有效地催化 HO 产生大量的 ROS。与传统的 HRP 样纳米酶不同，VC NDs 在略酸性条件（pH=5.5）下也能有良好的催化效果。此外，VC NDs 具有良好的近红外（NIR）吸收和高光热转换效率（PTCE，50.39%），可用于细菌的光热治疗（PTT）。此外，温和的光热效应可以进一步增强 VC NDs 的 HRP 样催化活性，从而进一步增强 VC NDs 的抗菌性能。体外结果表明，在激光照射和 HO 存在的情况下，VC NDs 可以有效地消除大肠杆菌（E. coli，革兰氏阴性）和耐甲氧西林金黄色葡萄球菌（MRSA，革兰氏阳性），具有广谱抗菌特性。更重要的是，VC NDs 在体内对 MRSA 感染的伤口表现出令人满意的治疗效果，其毒性可以忽略不计，这表明它们可能具有作为强大而安全的抗菌剂的巨大应用潜力。本工作提出了一种实用的抗菌策略，通过结合 PTT 和催化治疗来实现对细菌感染伤口的有效治疗。
