Immunomodulatory hybrid bio-nanovesicle for self-promoted photodynamic therapy

Thylakoid (Tk) membranes are of unique superiority in photodynamic therapy (PDT) because they not only carry abundant chlorophylls containing photosensitizer porphyrin but also can produce O₂. However, the current therapeutic performance of Tk is dramatically limited because of their poor tumor targeting and inefficient O₂ production. Here, we report an immunomodulatory bio-nanovesicle of Tk membranes fused with M1 macrophage-derived extracellular vesicles (M1 EV) for efficient PDT of tumors. The hybrid nanovesicle Tk@M1 was prepared by squeezing the Tk membranes of spinach with M1 EV. The systemic study confirmed that Tk@M1 can not only actively accumulate in tumors but also effectively regulate the inactive immune microenvironment of tumors. Such activated “hot” tumors significantly enhance the PDT efficacy of Tk@M1 attributed to the increased O₂ from catalase catalyzed decomposition of augmented H₂O₂, providing a novel idea about constructing natural systems for effective tumor treatment. [Figure not available: see fulltext.]