Micro/nano system-mediated local treatment in conjunction with immune checkpoint inhibitor against advanced-Stage malignant melanoma

Abstract

Tumor relapse and metastasis become a big challenge in treating malignant melanoma because conventional therapeutic options often fail to eradicate the tumor residue after surgical resection, posing huge threat to human health. Herein, a feasible strategy is developed for fighting crafty melanoma pre- and postsurgery. Specifically, nitric oxide (NO)-carried micelles (NOM) are designed by conjugating S-nitrosoglutathione (GSNO) with poly(2-ethyl-2-oxazoline)-b-poly(D, L-lactide) (PEOz-b-PLA) to form amphipathic polymer, which can self-assemble into pH-sensitive micelle to encapsulate chemotherapeutic drug paclitaxel (PTX). By further loading PTX@NOM into the needle tips of dissolvable microneedle (MN) patch, a local synergistic strategy is achieved for combating melanoma via easy insertion. Meanwhile, due to the immunomodulatory ability of NO by inducing the immunogenic cell death (ICD) of tumor cells and polarizing M2-like tumor-associated macrophages (TAMs) into antitumoral M1-like type, the “cold” immune microenvironment of melanoma is effectively remodeled. When combining with aPD-L1-based immune checkpoint blockade therapy, the treatment outcome of aPD-L1 is dramatically boosted, which not only suppresses primary tumor growth, but also inhibits the notorious post-operative melanoma recurrence and metastasis. Overall, this local strategy mediated by nanoparticle-loaded MN patch expands the therapeutic regimen for melanoma treatment in clinic.