Photothermally driven degradable nanomissile for single-wavelength phototherapy and hypoxia-activated chemotherapy

Viscous tumour tissue seriously affects the effective delivery of nanodrugs and reduces their anti-tumour effect. In order to solve this problem, a nanomotor (Cy7@ZIF-8@TPZ) for penetrating tumour tissue was synthesized. A new amphiphilic molecule Cy7 was designed and synthesized to wrap ZIF-8 loaded with TPZ to obtain the final nanomotor. The synthesized Cy7 can not only realize photodynamic therapy (PDT) and photothermal therapy (PTT) simultaneously under single-wavelength illumination, but also promote the movement of nanoparticles through thermal drive. Through the targeting ability of Cy7 and the enhanced permeability and retention (EPR) effect, the nanomotor can conduct directional deep puncture under illumination. The oxygen continuously consumed by PDT further activates hypoxia-activated chemotherapy, and the combined PTT/PDT/hypoxia-activated CT therapy greatly enhances the anti-tumour efficacy of Cy7@ZIF-8@TPZ. In addition, light-degradable Cy7, acid-degraded ZIF-8 and hypoxia-activated TPZ greatly reduce the side effects of nanomotors.