Xu Xiaomu, Liu Bo, Wu Haiyan, Zhang Yichi, Tian Xinyuan, Tian Jijing, Liu Tianlong
Laboratory of Veterinary Pathology and Nanopathology, College of Veterinary Medicine, China Agricultural University, No. 2 West Road Yuanmingyuan, Beijing 100193, China.
Nanomaterials (Basel). 2021 Dec 14;11(12):3394. doi: 10.3390/nano11123394.
Bacterial infections in wounded skin are associated with high mortality. The emergence of drug-resistant bacteria in wounded skin has been a challenge. Toluidine blue (TB) is a safe and inexpensive photosensitizer that can be activated and used in near-infrared photodynamic therapy to effectively kill methicillin-resistant (MRSA). However, its aggregation-induced quenching effect largely affects its clinical applications. In this study, TB nanoparticles (NPs) were synthesized using an ultrasound-assisted coating method. Their physicochemical and biological properties were studied and evaluated by scanning electron microscopy and Fourier-transform infrared spectroscopy. The TBNPs had a broad-spectrum antibacterial activity against Gram-positive bacteria (MRSA) and Gram-negative bacteria (). In addition, MTT, hemolysis, and acute toxicity tests confirmed that TBNPs had good biocompatibility. The TBNPs exhibited a high photodynamic performance under laser irradiation and efficiently killed and MRSA through generated reactive oxygen species, which destroyed the cell wall structure. The potential application of TBNPs in vivo was studied using an MRSA-infected wound model. The TBNPs could promote wound healing within 7 days, mainly by reducing the inflammation and promoting collagen deposition and granulation tissue formation. In conclusion, the TBNPs offer a promising strategy for clinical applications against multiple-drug resistance.
伤口皮肤中的细菌感染与高死亡率相关。伤口皮肤中耐药细菌的出现一直是个挑战。甲苯胺蓝（TB）是一种安全且廉价的光敏剂，可被激活并用于近红外光动力疗法以有效杀灭耐甲氧西林金黄色葡萄球菌（MRSA）。然而，其聚集诱导猝灭效应在很大程度上影响其临床应用。在本研究中，采用超声辅助包衣法合成了TB纳米颗粒（NPs）。通过扫描电子显微镜和傅里叶变换红外光谱对其理化和生物学性质进行了研究和评估。TBNPs对革兰氏阳性菌（MRSA）和革兰氏阴性菌具有广谱抗菌活性。此外，MTT、溶血和急性毒性试验证实TBNPs具有良好的生物相容性。TBNPs在激光照射下表现出高光动力性能，并通过产生的活性氧有效杀灭大肠杆菌和MRSA，从而破坏细胞壁结构。使用MRSA感染的伤口模型研究了TBNPs在体内的潜在应用。TBNPs可在7天内促进伤口愈合，主要是通过减轻炎症并促进胶原蛋白沉积和肉芽组织形成。总之，TBNPs为针对多重耐药性的临床应用提供了一种有前景的策略。
