Promotion of bone osteogenic and regeneration by resveratrol-derived carbon dots in inflammatory environments via a one-step hydrothermal method

Abstract

In the context of bone fractures, local inflammation complicates the healing process, adversely affecting the recovery of bone defects. This inflammatory response impedes the regenerative potential of stem cells and induces the differentiation of macrophages into the M1 type, thereby inhibiting bone regeneration. To address this issue, we synthesized carbon dots (CDs) using resveratrol and citric acid. These CDs demonstrated excellent water solubility and retained the anti-inflammatory properties of resveratrol. In an inflammatory environment co-cultured with resveratrol carbon dots (RES-CDs), we observed a reduction in inflammatory factors such as iNOS and an increase in anti-inflammatory factors like CD206. Alkaline phosphatase (ALP) activity, Alizarin Red staining, and immunofluorescence assays indicated that MC3T3 cells produced more calcium nodules after co-culture with RES-CDs, along with enhanced expression of bone formation factors BMP-2 and ALP. Additionally, real-time polymerase chain reaction (qRT-PCR) and immunofluorescence analysis demonstrated that RES-CDs could induce bone tissue proliferation and differentiation by upregulating ALP, BMP-2, OCN, and OPN. In a rat cranial defect model, RES-CDs promoted tissue healing and bone proliferation at weeks 1 and 4 post-surgery. These findings underscore the potential of resveratrol carbon dots in promoting bone tissue healing while mitigating inflammation, thereby offering a promising approach for nanocomposite materials in tissue repair.