Nanomedicine delivery systems remodel the immunosuppressive microenvironment of colorectal cancer: synergistic strategies and mechanisms of targeted immune checkpoint inhibitors

Colorectal cancer (CRC) is a highly prevalent malignancy worldwide. Traditional treatments, including surgery, chemotherapy, and radiotherapy, have limited efficacy in advanced-stage patients, therefore innovative strategies are urgently needed. Targeted immunotherapy and nanomedicine, as emerging therapeutic directions, offer new possibilities to address this therapeutic impasse. This review systematically summarizes the current application of targeted immunotherapy (immune checkpoint inhibitors, CAR-T cell therapy, and tumor vaccines) in CRC, as well as the research progress of nanomedicine (e.g., liposomes, polymeric nanoparticles, and metal nanoparticles) in drug delivery, immunomodulation, and combination therapy. By analyzing the latest research findings, this review explores the synergistic mechanisms of these two approaches, the clinical challenges, and future development directions, aiming to provide a theoretical basis and practical guidance for the precision treatment of CRC.