Recent advances and clinical challenges of phototherapeutic nanoparticles in cancer monotherapy or combination therapy

In the past decades, phototherapy has been explored in the field of cancer treatment owing to its advantages of high selectivity, excellent efficiency, and negligible drug resistance. Phototherapy relies on agents that generate hyperthermia or reactive oxygen species to allow specific targeting and tumor ablation. However, mono-phototherapy only shows modest efficiency, which cannot fight recalcitrant tumors completely and is usually accompanied by recurrence or metastasis, especially in clinics. Therefore, combining other therapeutic strategies (e.g., chemotherapy, radiotherapy, immunotherapy, gene therapy, anti-angiogenesis therapy, sonodynamic therapy, gas therapy, chemodynamic therapy, and starvation therapy) or novel modifications with phototherapy greatly increases clinical therapeutic potential and opens new horizons in oncology treatment. This review outlines the latest advances in phototherapeutic-based nanoparticles to fight cancer and their preclinical and clinical developments. First, cancer mono-phototherapy is summarized. Subsequently, phototherapy strategies combined with other therapeutic methods are reviewed. Finally, major challenges and perspectives of cancer phototherapy are discussed. This review provides a detailed introduction to cancer phototherapy and the combination strategies that promote significant remediation for future clinical translation.