Cancer treatment remains challenging due to the complexity of the tumor microenvironment, which promotes tumor heterogeneity and contributes to the development of multidrug resistance, ultimately hindering drug delivery and reducing therapeutic efficacy. In recent years, biomimetic nanocarriers have emerged as promising tools to address these challenges. Among them, cancer cell membrane (CCM)-coated nanoparticles (CCM-NPs) have attracted increasing attention due to their unique advantages, including homologous targeting, prolonged circulation mediated by self-recognition, and enhanced tumor penetration. Moreover, CCM-NPs can serve as versatile platforms for tumor vaccines by leveraging their inherent tumor-associated antigens and immunomodulatory potential. By leveraging CCMs to functionalize NPs, researchers have developed innovative approaches to improve drug delivery, enhance tumor immunotherapy, and optimize cancer vaccine efficacy. Despite these advancements, a comprehensive review summarizing the latest progress in CCM-based biomimetic nanocarriers for tumor treatment is lacking. This review integrates recent advances in CCM-NPs for targeted drug delivery and cancer vaccination, and discusses their fabrication, characterization, mechanisms and applications across multiple cancer types, which provides timely insights to guide their future development in precision tumor therapy.

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous subtype lacking effective targeted therapies. Its tumor microenvironment (TME) exhibits distinct features, including acidity, redox imbalance, elevated reactive oxygen species (ROS), and hypoxia, which provide exploitable triggers for targeted drug delivery. Stimuli-responsive polymeric nanocarriers have emerged as promising platforms that enable spatiotemporally controlled and site-specific therapeutic release in response to these endogenous cues, as well as exogenous stimuli such as temperature and light. These systems improve drug accumulation, penetration, and therapeutic efficacy while reducing systemic toxicity. Unlike previous reviews that broadly discuss nanocarriers in cancer therapy, this review focuses on the structure–function relationships of TME-responsive polymeric systems in TNBC and their translational limitations. We summarize recent advances in pH-, redox-, ROS-, hypoxia-, photo- and temperature-responsive polymers, highlighting their design strategies and therapeutic applications. Key challenges, including stimulus heterogeneity, limited in vivo validation, and clinical translation barriers, are also discussed. This review provides a concise framework for the rational design of programmable, multi-responsive polymeric nanomedicines for TNBC therapy.