College of Food Science, Northeast Agricultural University, Harbin, 150030, China.
Department of Chemistry, Northeast Agricultural University, Harbin, 150030, China.
J Nanobiotechnology. 2021 Dec 28;19(1):456. doi: 10.1186/s12951-021-01211-w.
Carbon dots (CDs) are widely used in cell imaging due to their excellent optical properties, biocompatibility and low toxicity. At present, most of the research on CDs focuses on biomedical application, while there are few studies on the application of microbial imaging.
In this study, B- and N-doped carbon dots (BN-CDs) were prepared from citric acid, ethylenediamine, and boric acid by microwave hydrothermal method. Based on BN-CDs labeling yeast, the dead or living of yeast cell could be quickly identified, and their growth status could also be clearly observed. In order to further observe the morphology of yeast cell under different lethal methods, six methods were used to kill the cells and then used BN-CDs to label the cells for imaging. More remarkably, imaging of yeast cell with ultrasound and antibiotics was significantly different from other imaging due to the overflow of cell contents. In addition, the endocytosis mechanism of BN-CDs was investigated. The cellular uptake of BN-CDs is dose, time and partially energy-dependent along with the involvement of passive diffusion. The main mechanism of endocytosis is caveolae-mediated.
BN-CDs can be used for long-term stable imaging of yeast, and the study provides basic research for applying CDs to microbiol imaging.
由于其优异的光学性质、生物相容性和低毒性，碳点（CDs）被广泛应用于细胞成像。目前，CDs 的研究大多集中在生物医学应用上，而关于微生物成像的应用研究较少。
本研究采用微波水热法，以柠檬酸、乙二胺和硼酸为原料制备了 B、N 共掺杂碳点（BN-CDs）。基于 BN-CDs 对酵母的标记，可以快速识别酵母细胞的死活，并能清晰观察其生长状态。为了进一步观察不同致死方法下酵母细胞的形态，采用 6 种方法杀死细胞，然后用 BN-CDs 对细胞进行标记成像。更值得注意的是，由于细胞内容物溢出，超声和抗生素处理的酵母细胞成像与其他方法明显不同。此外，还研究了 BN-CDs 的内吞作用机制。BN-CDs 的细胞摄取呈剂量、时间和部分能量依赖性，同时涉及被动扩散。内吞作用的主要机制是网格蛋白介导的。
BN-CDs 可用于酵母的长期稳定成像，该研究为将 CDs 应用于微生物成像提供了基础研究。
