A switchable NO-releasing nanomedicine for enhanced cancer therapy and inhibition of metastasis.

Clinical chemotherapy for cancer is limited by the physiological barrier of tumors, resulting in low drug delivery to tumors, poor efficacy of drugs and inability to block tumor metastasis. Here we developed an intelligent switchable nitric oxide (NO)-releasing nanoparticle, IPH-NO, which loads a photosensitizer (IR780) and the chemotherapy drug paclitaxel (PTX) into NO donor-S-nitrosated human serum albumin (HSA-NO). NO exhibits two effects based on its concentration: enhancement of chemotherapy by increasing the enhanced permeability and retention (EPR) effect at low concentrations and direct killing of cancer cells at high concentrations.