Near-infrared and ultrasound triggered Pt/Pd-engineered cluster bombs for the treatment of solid tumors.

ABSTRACT

Owing to the dense extracellular matrix and high interstitial fluid pressure in the tumor microenvironment, methods which enhance the permeation and retention of nano drugs into liver tumors remain unsatisfactory for successful tumor treatment. We designed a near-infrared (NIR)- and ultrasound (US)-triggered Pt/Pd-engineered "cluster bomb" (Pt/Pd-CB) which actively penetrates liver cancer cell membranes and achieves photothermal and sonodynamic therapy (SDT). The physical forces generated by the fast expansion and collapse of perfluoropentane nanodroplets eject "sub bombs" (Pt/Pd nanoalloys) into liver cancer cells upon activation by NIR and US. Pt/Pd nanoalloys can then convert H2O2 into O2 to alleviate hypoxia and boost SDT efficiency while exhibiting a highly efficient photothermal response under NIR irradiation. Our findings might especially be promising for the treatment of solid tumors.