Abstract

The tumor microenvironment (TME) plays a pivotal role in cancer initiation, progression, metastasis, and 
therapeutic resistance. It comprises a dynamic and complex network of tumor cells, stromal cells, immune cells, 
extracellular matrix (ECM), cytokines, and blood vessels that collectively support tumor growth. Conventional 
cancer therapies often fail to address the multifaceted nature of the TME, resulting in limited efficacy and 
relapse. Nanotechnology offers an innovative platform to precisely modulate the TME by reprogramming its 
components and restoring antitumor immunity. This review provides a comprehensive analysis of the current 
advances in nanotechnology-based strategies for TME modulation, including normalization of tumor 
vasculature, remodeling of the ECM, reprogramming of tumor-associated macrophages (TAMs), targeting 
cancer-associated fibroblasts (CAFs), alleviating hypoxia, and modulating immunosuppressive pathways. We 
also discuss the design considerations of nanocarriers, such as size, surface charge, and targeting ligands, which 
enhance their accumulation and retention in the tumor site. Furthermore, we highlight the integration of 
nanotechnology with emerging therapies such as immune checkpoint inhibitors, CAR-T cells, and tumor 
vaccines to achieve synergistic effects. Despite promising preclinical results, challenges remain in translating 
these approaches to the clinic due to heterogeneity of the TME, nanotoxicity concerns, and regulatory hurdles. 
Future perspectives call for the development of multifunctional, stimuli-responsive, and personalized 
nanomedicine to achieve efficient TME reprogramming and improved cancer outcomes.