Recent Advances in Nanomedicine for Modulating Intratumoral Bacteria in Cancer Therapy

Cancer is a critical global public health issue, and conventional therapies (surgery, chemotherapy, and radiotherapy) are limited by adverse effects and tumor resistance. Emerging evidence underscores the role of intratumoral bacteria in exacerbating tumor progression, metastasis, and therapeutic resistance via the modulation of cancer cell dynamics and the tumor microenvironment. These bacteria also present translational potential as diagnostic, therapeutic, and prognostic targets. However, antibiotic-based strategies to reduce the bacterial burden often disrupt the commensal microbiota, induce resistance, and compromise therapeutic efficacy. Nanomedicines, characterized by enhanced biocompatibility, targeted delivery, and minimal systemic toxicity, have emerged as precision therapeutic modalities for intratumoral bacterial modulation. By eliminating pathogenic bacteria, reprogramming the immunosuppressive tumor microenvironment, and synergistically enhancing antitumor responses, nanoplatforms offer transformative potential in oncology. This review systematically summarizes recent advances in nanomedicine-based strategies for regulating intratumoral bacteria. On the basis of the composition of nanocarriers, nanomedicines are categorized into three major classes: polymeric nanoparticles, lipid-based and biorelated nanomaterials, and inorganic nanomaterials, and their potential clinical applications are discussed. By highlighting these advances, this review offers new perspectives and innovative strategies for improving cancer therapy.