In vitro and in vivo chemo-phototherapy of magnetic TiO2 drug delivery system formed by pH-sensitive coordination bond.

To achieve tumor-specific delivery of doxorubicin, TiO2 @Fe3 O4 /PEI/delivery of doxorubicin conjugates were designed and synthesized. Fe3 O4 could act as magnetically responsive carriers and enhance the visible light photodynamic activities of TiO2 Delivery of doxorubicin was conjugated via coordination bond. The drug release rate at pH 5.2 was much faster than that at pH 7.4, due to pH-sensitive coordination bond. Besides, TiO2 @Fe3 O4 /PEI/delivery of doxorubicin showed high antitumor efficacy combining with phototherapy, good bio-safety, higher cellular uptake with an external magnetic field, and less toxicity in vitro and in vivo. These results suggested that TiO2 @Fe3 O4 /PEI/delivery of doxorubicin may be promising for high tumor treatment efficacy with minimal side effects in future.