Platelet-derived exosomes hybrid liposomes facilitate uninterrupted singlet oxygen generation to enhance breast cancer immunotherapy

The development of strategies to maintain the long-term presence of reactive oxygen species in tumor sites remains an urgent issue to be addressed. Here, we design platelet exosome hybrid liposome nanovesicles (named platelet-derived exosome hybrid liposomes co-loaded with DPDPy and chloroperoxidase [DCHL]) co-loading aggregation-induced emission (AIE) photosensitizers and chloroperoxidases to facilitate uninterrupted singlet oxygen ( 1 O 2 ) generation for enhancing breast cancer immunotherapy. When DCHL enters tumor cells, it lyses under external laser irradiation, thus releasing AIE photosensitizers (DPDPy) and chloroperoxidase. Subsequently, chloroperoxidase utilizes hydrogen peroxide (H 2 O 2 ) and chloride to synthesize HClO, and, as a second step, HClO reacts with H 2 O 2 to form 1 O 2 . Therefore, uninterrupted 1 O 2 generation is achieved. The experimental results show that DCHL plus light can lead to systemic immune response, increase the proportion of central memory T cells and tumor-infiltrating T cells, and thereby delay tumor recurrence and rechallenge. Overall, the DCHL system provides a good idea for the design of tumor treatment system.