Alendronate-derived carbon dots for bioimaging and effective osteoblastic differentiation induction and promotion

Carbon dots (CDs) belong to zero-dimensional carbon-based nanomaterials, which are promising in various biomedical applications including imaging, biosensing and drug delivery. In this work, we have synthesized novel fluorescent CDs (Alen-CDs) derived from alendronate, an anti-osteoporosis drug, through a one-step hy-drothermal method. The ability of Alen-CDs for fluorescent imaging was evaluated via in vitro cellular bio-imaging. In addition, the capability of Alen-CDs to induce in vitro osteoblastic differentiation was investigated by alkaline phosphatase staining, activity test and alizarin red staining. As demonstrated, Alen-CDs was effective for in vitro fluorescent imaging without obvious toxicity. Also, Alen-CDs promoted the survival of rat bone marrow mesenchymal stem cells and stimulated osteoblastic differentiation. In conclusion, Alen-CDs are a new type of nanomaterial with good biocompatibility and fluorescent properties. Alen-CDs could be applied as a potential probe for bioimaging and a promising nanodrug for bone regeneration as well as the combination to be used as a theranostic agent.