Engineering PDA-coated CM-CS nanoparticles for photothermo-chemotherapy of osteosarcoma and bone regeneration

After an osteosarcoma excision, recurrence and bone defects are significant challenges for clinicians. Combination therapy based on a nanoparticle-based drug delivery system shows great promise in osteosarcoma therapy. In this study, we designed a multifunctional chitosan (CS) nanoparticle , which combined photothermal therapy (PTT) with chemotherapy to synergistically enhance osteosarcoma therapy and bone repair . Curcumin (CM) loaded CS nanoparticles were prepared through ionotropic gelation method and were further functionalized with polydopamine (PDA) coating to form CS-CM-PDA nanoparticles (CCPNPs). The CCPNPs displayed pH- and near-infrared (NIR)- responsive CM release behavior. In vitro anti-cancer results indicated that CCPNPs possessed a long-term stable anti-cancer effect compared to pure CM. The presence of the NIR irradiation combined with CCPNPs resulted in a dramatic decrease in MG-63 osteosarcoma cell viability in 10 min compared with the pure CCPNPs at the concentration of 500 μg/mL. Meanwhile, in vitro study demonstrated that CCPNPs induced MG-63 cell apoptosis via downregulating the expression of Bcl-2 and upregulating the expression levels of Bax and Caspase-3. Besides, CCPNPs could positively induce the proliferation of MC3T3-E1 osteoblast cells in vitro . These results suggested that CCPNPs with bifunctional osteosarcoma therapy and bone repair may be an excellent candidate for local cancer therapy and bone regeneration .