Implantable composite fibres with Self-supplied H2O2 for localized chemodynamic therapy

The anticancer efficacy of chemodynamic therapy (CDT) is considerably restrained by the inadequate content of H2O2 within tumor microenvironment (TME), unexpected oxidation of Fenton agents and low targeting efficiency of particulate therapeutic platforms. Herein for the first time, an implantable CDT platform was designed and synthesized by combining Fe-0 nanocrystal embedded mesoporous silica nanoparticles (FeMSN) and PCL-gelatin fibres (PG fibres), denoted as FeMSN@PG fibres. FeMSN was fabricated via in situ reduction of ferrous ions within the mesopores of MSNs, and assembled at the surface of electrospun PG fibres by electrostatic interaction to form a fibrous mesh. The findings reflected that, in an acid condition, FeMSN nanoparticles can liberate from the composite fibres, and be effectively uptaken by 4T1 cancer cells. The FeMSN released may react with oxygen to generate H2O2 in the acidic microenvironment, and subsequently transform H2O2 to intracellular hydroxyl radicals, inducing enhanced cell-killing effect. By implanting the composite fibres locally at the tumor site of mice, promoted anticancer efficacy was observed with comparison of the intratumoral-injected FeMSN nanoparticles. This study suggests that FeMSN@PG composite fibres can serve as a potential localized PDT platform for effective antitumor purposes, which may spark a series of follow-on investigations for localized cancer therapeutic technology.