Background: Understanding the biocompatibility and biointeractions of nano-carbon quantum dots (nano-CQDs) in vitro and in vivo is important for assessing their potential risk to human health. In the previous research, the physical properties of CQDs synthesized by the laser ablation in liquid (LAL) method were analyzed in detail; however, possible bioapplications were not considered.
Materials and Methods: CQDs were prepared by LAL and characterized by atomic force microscopy, fluorescence lifetime, absorption spectrum, Fourier-transform infrared spectroscopy, and dynamic light scattering. Their biocompatibility was evaluated in vitro using assays for cytotoxicity, apoptosis, and biodistribution and in vivo using immunotoxicity and the relative expression of genes. Cells were measured in vitro using fluorescence-lifetime imaging microscopy to analyze the biointeractions between CQDs and intracellular proteins.
Results: There were no significant differences in biocompatibility between the CQDs and the negative control. The intracellular interactions had no impact on the optical imaging of CQDs upon intake by cells. Optical imaging of zebrafish showed the green fluorescence was well dispersed.
Conclusion: We have demonstrated that the CQDs have an excellent biocompatibility and can be used as efficient optical nanoprobes for cell tracking and biomedical labeling except for L929 and PC-3M cells.



中文翻译：

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碳量子点：光学成像生物相容性和生物相互作用的体外和体内研究。


背景：了解纳米碳量子点（nano-CQD）在体外和体内的生物相容性和生物相互作用对于评估其对人类健康的潜在风险非常重要。前期研究对液体激光烧蚀（LAL）法合成的CQDs的物理性质进行了详细分析；然而，没有考虑可能的生物应用。

材料和方法： CQD 采用 LAL 制备，并通过原子力显微镜、荧光寿命、吸收光谱、傅里叶变换红外光谱和动态光散射进行表征。它们的生物相容性在体外使用细胞毒性、细胞凋亡和生物分布测定进行评估，在体内使用免疫毒性和基因的相对表达进行评估。使用荧光寿命成像显微镜在体外测量细胞，以分析 CQD 和细胞内蛋白质之间的生物相互作用。

结果： CQD 与阴性对照之间的生物相容性没有显着差异。细胞内相互作用对细胞摄取后 CQD 的光学成像没有影响。斑马鱼的光学成像显示绿色荧光分散良好。

结论：我们已经证明，CQD 具有优异的生物相容性，可用作除 L929 和 PC-3M 细胞外的细胞追踪和生物医学标记的有效光学纳米探针。