Mesenchymal stem cells (MSCs) hold great potential for tissue engineering and regeneration medicine. However, for clinical use, MSCs may be detrimental due to their uncertain fate during the transplantation. It is therefore highly desirable to develop biocompatible nanomaterials to integrate cell fate regulation with monitoring for MSC-based therapy. Herein, we employ recently developed citric acid-based carbon dots (CDs) and their derivatives (Et-IPCA) for labeling and tracking of rat bone marrow mesenchymal stem cells (rBMSCs). We further investigate their biocompatibility and effects on the osteogenic differentiation of rBMSCs. These highly fluorescent probes provide labeling of rBMSCs by internalization without affecting cell viability or inducing apoptosis when the concentration is lower than 50 μg mL⁻¹. Importantly, the presence of the CDs and Et-IPCA facilitates high-efficiency osteogenic differentiation of rBMSCs by promoting osteogenic transcription and enhancing matrix mineralization. Compared to Et-IPCA, CDs considerably provide long-term tracking and promote the differentiation of rBMSCs toward osteoblasts through the ROS-mediated MAPK pathway. Taken together, our results consistently demonstrate that carbon dots are capable of both tracking and enhancing the osteogenic differentiation of MSCs. This study sheds new light on the potential of carbon dots as a bifunctional tool in the thriving field of MSC-based therapy.

中文翻译：

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用于追踪和促进间充质干细胞成骨分化的碳点†

间充质干细胞（MSCs）在组织工程和再生医学中具有巨大的潜力。但是，对于临床使用，MSC可能会因其在移植过程中的命运不确定而有害。因此，非常需要开发生物相容性纳米材料，以将细胞命运调控与基于MSC的治疗监测相结合。在这里，我们采用最近开发的柠檬酸基碳点（CDs）及其衍生物（Et-IPCA）标记和跟踪大鼠骨髓间充质干细胞（rBMSCs）。我们进一步研究了它们的生物相容性和对rBMSCs成骨分化的影响。当浓度低于50μgmL ^-1时，这些高荧光探针可通过内化作用标记rBMSC，而不会影响细胞生存力或诱导细胞凋亡。重要的是，CD和Et-IPCA的存在通过促进成骨转录和增强基质矿化作用，促进了rBMSC的高效成骨分化。与Et-IPCA相比，CD可通过ROS介导的MAPK途径提供长期跟踪并促进rBMSC向成骨细胞的分化。两者合计，我们的结果一致证明碳点能够跟踪和增强MSC的成骨分化。这项研究揭示了碳点作为基于MSC的疗法蓬勃发展的一种双功能工具的潜力。