Polyethylene glycol modified PAMAM dendrimer delivery of kartogenin to induce chondrogenic differentiation of mesenchymal stem cells.

Partly PEGylated polyamidoamine (PAMAM) dendrimer was used as the nanocarrier for the cytoplasmic delivery of kartogenin (KGN) to induce chondrogenic differentiation of mesenchymal stem cells (MSCs). Here, KGN was conjugated to the surface of PAMAM and the end group of polyethylene glycol (PEG) to obtain PEG-PAMAM-KGN (PPK) and KGN-PEG-PAMAM (KPP) conjugate, respectively. The effects of PPK and KPP on the in vitro chondrogenic differentiation of MSCs were evaluated. KPP induced higher expression of chondrogenic markers than PPK and free KGN. In particular, after treatment of KPP, CBF β nuclear localization intensity was significantly increased, indicating enhanced efficacy of chondrogenesis. The fluorescein labeled PEG-PAMAM was capable to persist in the joint cavity for a prolonged time of both healthy and osteoarthritis (OA) rats. Thus, PEG-PAMAM could be a useful nanocarrier for intra-articular (IA) delivery of drug to treat OA.