An in-vitro study of enzyme-responsive Prussian blue nanoparticles for combined tumor chemotherapy and photothermal therapy.

In the development of advanced photothermal therapy (PTT), there is an unmet demand for constructing novel multifunctional agent for efficient cancer therapy in a synergic manner. In this study, a system based on gelatin-stabilized Prussian blue nanoparticles with conjugated doxorubicin (PB@Gel-DOX NPs) is proposed for combined photothermal therapy and enzyme-responsive drug release for tumor destruction. Monodispersed PB@Gel-DOX NPs (55.7±4.8 nm) are synthesized using citric acid and gelatin-DOX as surface capping agent and protective colloid, respectively, which can be used as a promising NIR-light absorber with high photothermal conversion efficiency for PTT. Furthermore, the drug-loaded carriers are stable in physiological environment and drug release can be successfully triggered in the presence of gelatinase. The efficacy of combining photothermal therapy and chemotherapy is evaluated by cell viability assay in vitro. This proof-of-concept study shows that such versatile drug delivery system has a good potential for the next generation of multifunctional platforms for cancer therapy.