Tumor-microenvironment activated duplex genome-editing nanoprodrug for sensitized near-infrared titania phototherapy

Near-infrared (NIR)-light-triggered nanomedicine, including photodynamic therapy (PDT) and photothermal therapy (PTT), is growing an attractive approach for cancer therapy due to its high spatiotemporal controllability and minimal invasion, but the tumor eradication is limited by the intrinsic anti-stress response of tumor cells. Herein, we fabricate a tumor-microenvironment responsive CRISPR nanoplatform based on oxygen-deficient titania (TiO 2- x ) for mild NIR-phototherapy. In tumor microenvironment, the overexpressed hyaluronidase (HAase) and glutathione (GSH) can readily destroy hyaluronic acid (HA) and disulfide bond and releases the Cas9/sgRNA from TiO 2- x to target the stress alleviating regulators, i.e. , nuclear factor E2-related factor 2 (NRF2) and heat shock protein 90 α (HSP90 α ), thereby reducing the stress tolerance of tumor cells. Under subsequent NIR light illumination, the TiO 2- x demonstrates a higher anticancer effect both in vitro and in vivo . This strategy not only provides a promising modality to kills cancer cells in a minimal side-effects manner by interrupting anti-stress pathways but also proposes a general approach to achieve controllable gene editing in tumor region without unwanted genetic mutation in normal environments.