Nano-enabled photosynthesis in tumours to activate lipid peroxidation for overcoming cancer resistances.

Apoptosis dysregulation is an important mechanism responsible for the intrinsic and acquired resistance of melanoma, which necessitates the exploration of oncological treatments to activate nonapoptotic cell death. Herein, we developed nano-enabled photosynthesis in tumours to activate lipid peroxidation and ferroptosis to overcome melanoma resistance. Controlled photosynthesis was conducted in tumours to construct a hyperoxic microenvironment with photosynthetic microcapsules (PMCs), which were prepared by encapsulating cyanobacteria and upconversion nanoparticles in alginate microcapsules and driven by external near infrared photons. The combination of PMCs and X-rays evoked lipid peroxidation, Fe release, glutathione peroxidase 4 suppression, glutathione reduction and ferroptosis in melanoma cells and xenografts. Consequently, the intrinsic and acquired resistance in melanoma could be overcome by the combined treatment, which further inhibited tumour metastases and improved the survival rate of melanoma-bearing mice. Overall, the development of nano-enabled photosynthesis in tumours will inspire the exploration of oncological treatments.