Calcium and phosphorus co-doped carbon dots enhance osteogenic differentiation for calvarial defect repair in situ

Calvarial bone defect remains a clinical challenge due to the lack of efficient osteo-inductive agent. Herein, a novel calcium and phosphorus codoped carbon dot (Ca/P-CD) for bone regeneration was synthesized using phosphoethanolamine and calcium gluconate as precursors. The resultant Ca/P-CDs exhibited ultra-small size, stable excitation dependent emission spectra and favorable dispersibility in water. Moreover, Ca/P-CDs with good biocompatibility rapidly entered the cytoplasm through endocytosis and increased the expression of bone differentiation genes. After mixing with temperature-sensitive hydrogel, Ca/P-CDs were injected in situ into calvarial defect and promoted the repair of bone injury. These Ca/P-CDs provide a new treatment method for the bone repair and should be expended the application in the biomedical fields.