Although a promising strategy, the mesenchymal stem cell (MSC)‐based therapy of cartilage defects is sometimes accompanied with chronic inflammation during the remodeling status, which may hinder cartilage regeneration. During this process, the inflammatory cytokine tumor necrosis factor α (TNFα) plays an important role and may be a potential target. In this study, we investigated the effect of
Tnfα
RNA interference by introducing a functional and highly safe carbon dot (CD)‐SMCC nanovector synthesized by bioconjugation of CDs with a protein crosslinker, sulfosuccinimidyl‐4‐(N‐maleimidomethyl) cyclohexane‐1‐carboxylate (sulfo‐SMCC), as the vehicle of the silenced TNFα (si
Tnfα
) on chondrogenesis of MSCs. The results showed that CD‐SMCC displayed intense fluorescence with well‐dispersed and positively charged properties, which favored effective binding and delivering of si
Tnfα
into the MSCs. CD‐SMCC‐si
Tnfα
nanoformula also exhibited considerably high transfection efficiency and nearly no cytotoxicity, which is preferred over commercial polyethyleneimine. Interference of
Tnfα
by CD‐SMCC‐si
Tnfα
markedly promoted the chondrogenesis of MSCs, as indicated by upregulating cartilage‐specific markers. Furthermore, in vivo exploration indicated that CD‐SMCC‐si
Tnfα
transfected MSCs accelerated cartilage regeneration. In conclusion, this study demonstrated that in combination with the novel CD‐SMCC nanovector, targeting
Tnfα
may facilitate stem cell‐based therapy of cartilage defects.
stem cells translational medicine
2019;8:724&736