Nanomedicines for combining chemotherapy and sonodynamic therapy (SDT) have enormous potential in squamous cell carcinoma treatment. However, the therapeutic efficacy of noninvasive SDT is severely limited because the generation of reactive oxygen species (ROS) by sonosensitizers is highly dependent on the levels of intracellular excess glutathione (GSH) in the tumor cells. To overcome this barrier, a red blood cell (RBC) membrane-camouflaged nanomedicine consisting of GSH-sensitive polyphosphoester (SS-PPE) and ROS-sensitive polyphosphoester (S-PPE) was designed for the simultaneous delivery of the sonosensitizer hematoporphyrin (HMME) and chemotherapeutic agent docetaxel (DTXL) for effectively enhanced antitumor efficacy. In vitro and in vivo studies demonstrated that HMME-driven ROS generation under ultrasound (US) inhibited SCC7 cell proliferation and accelerated DTXL release to further kill tumor cells via the hydrophobic-hydrophilic transition of the nanoparticle core. Meanwhile, the disulfide bond of SS-PPE effectively consumes GSH to prevent ROS consumption. This biomimetic nanomedicine provides GSH depletion and amplified ROS generation capabilities to achieve a novel synergistic chemo-SDT strategy for squamous cell carcinomas.
Keywords: chemo-sonodynamic therapy; glutathione depletion; head and neck cancer; oxidative stress; red blood cell membrane.