Chimeric antigen receptor (CAR) immune cell therapies have revolutionized oncology, particularly in hematological malignancies, yet their efficacy against solid tumors remains limited due to challenges such as dense stromal barriers and immunosuppressive microenvironments. With advancements in nanobiotechnology, researchers have developed various strategies and methods to enhance the CAR cell efficacy in solid tumor treatment. In this Review, we first outline the structure and mechanism of CAR-T (T, T cell), CAR-NK (NK, natural killer), and CAR-M (M, macrophage) cell therapies and deeply analyze the potential of these cells in the treatment of solid tumors and the challenges they face. Next, we explore how biomaterials can optimize these treatments by improving the tumor microenvironment, controlling CAR cell release, promoting cell infiltration, and enhancing efficacy. Finally, we summarize the current challenges and potential solutions, emphasize the effective combination of biomaterials and CAR cell therapy, and look forward to its future clinical application and treatment strategies. This Review provides important theoretical perspectives and practical guidance for the future development of more effective solid tumor treatment strategies.
Keywords: CAR immune cell; biomaterials; delivery strategies; immunotherapy; solid tumors.