Microneedle patch-involved local therapy synergized with immune checkpoint inhibitor for pre- and post-operative cancer treatment

The metastasis and recurrence of cancer post-surgery remain the major reasons for treatment failures. Herein, a photo-immune nanoparticle decorating with M1 macrophage membrane (BD@LM) is designed based on the inflammatory environment after surgical resection. By loading photosensitizer black phosphorus quantum dots (BPQDs) and chemotherapeutics doxorubicin (DOX) in BD@LM nanoparticles, an effective chemophototherapy-mediated immunogenic cell death of tumor cells is triggered, subsequently leading to the maturation of dendritic cells for further immune cascade. Moreover, by accommodating BD@LM in a dissolvable microneedle patch, the skin barrier is directly broken for efficacious delivery of BD@LM into solid tumors, which boosts the effectiveness of aPD-L1-based checkpoint blockade therapy. Consequently, the growth of both orthotopic and post-surgical breast tumor and melanoma is significantly inhibited. Specifically, an effective T cell activation accompanied with dramatic inhibition of immunosuppressive cells is observed. Meanwhile, the proportion of memory T cells remarkably grows after proposed treatment, indicating the establishment of a long-term immune memory effect for prevention of second tumor attack. Altogether, this work offers a meaningful strategy by combining photo-immune-inspired nanoparticles with microneedle patches for boosting aPD-L1-based tumor immunotherapy.