Department of Pharmaceutical Analysis, School of Pharmacy, Fujian Medical University, Fuzhou 350122, China.
Department of Orthopedic Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, China.
Colloids Surf B Biointerfaces. 2019 Jul 1;179:17-27. doi: 10.1016/j.colsurfb.2019.03.042. Epub 2019 Mar 19.
Antimicrobial resistance is becoming more and more serious and has become a potential hazard to human life and health. The fabrication of some new antibacterial substances against resistant bacteria is demanded. With the wide application and research of carbon nanomaterials, nitrogen-doped carbon quantum dots (NCQDs) were synthesized by a one-step chemical route herein. The particle size of NCQDs in the range of 2-5 nm were characterized by transmission electron microscopy (TEM), atomic force microscopy, and dynamic light scattering. The functional groups and optical properties of NCQDs were investigated by UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Disk-diffusion tests showed that the NCQDs had specific antibacterial activity against Staphylococcus. TEM showed that the NCQDs could destroy the cell structure of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) but could not combat Escherichia coli. The antibacterial mechanism may be that positively charged NCQDs firstly interacted with the negatively charged bacteria, and then specifically anchored on some specific sites on the surface of Staphylococcus. The NCQDs were applied to treat wounds infected with MRSA and showed the same therapeutic effect as vancomycin. Photomicrographs of hematoxylin-eosin-stained histological sections showed that the NCQDs at concentrations effectively killing S. aureus and MRSA caused negligible toxicity to the main rat organs, including heart, liver, spleen, lung, and kidney. Thus, the NCQDs can be developed as a promising antibacterial agent for Staphylococcus. And the NCQDs are likely to treat local infections caused by Staphylococcus clinically, especially S. aureus and MRSA.
抗菌耐药性日益严重，已经成为人类生命健康的潜在威胁。因此，人们迫切需要研发一些针对耐药菌的新型抗菌物质。随着碳纳米材料的广泛应用和研究，本文采用一步化学法合成了氮掺杂碳量子点（NCQDs）。透射电子显微镜（TEM）、原子力显微镜和动态光散射表明 NCQDs 的粒径在 2-5nm 范围内。紫外-可见吸收光谱、X 射线光电子能谱和傅里叶变换红外光谱研究了 NCQDs 的官能团和光学性质。圆盘扩散试验表明 NCQDs 对金黄色葡萄球菌具有特定的抗菌活性。TEM 表明 NCQDs 可以破坏金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌（MRSA）的细胞结构，但不能对抗大肠杆菌。抗菌机制可能是带正电荷的 NCQDs 首先与带负电荷的细菌相互作用，然后特异性地锚定在金黄色葡萄球菌表面的某些特定部位。NCQDs 被用于治疗感染 MRSA 的伤口，其治疗效果与万古霉素相同。苏木精-伊红染色组织学切片的光镜照片显示，有效杀死金黄色葡萄球菌和 MRSA 的 NCQDs 浓度对大鼠的主要器官（包括心、肝、脾、肺和肾）几乎没有毒性。因此，NCQDs 可以作为一种有前途的治疗金黄色葡萄球菌的抗菌剂。NCQDs 可能在临床上用于治疗由金黄色葡萄球菌引起的局部感染，尤其是金黄色葡萄球菌和 MRSA。
