Light-guided tumor diagnosis and therapeutics: From nanoclusters to polyoxometalates

Malignant tumors, with the characteristics of easy metastasis and recurrence, are a serious threat to health of mankind. It is urgent to develop promising clinical cancer targeted agents with combination of rapid diagnosis and efficient therapies. Compared with the conventional photosensitizing agents, the recent advances of nanoagents based on transition metal-oxide clusters possess unique structural and electronic properties, greatly improving cancer survival rate, meanwhile, keeping high contrast imaging. This review provides a brief introduction of metal-oxide clusters, including both nanoclusters to molecular clusters, specifically polyoxometalates (POMs). Subsequently, biocompatibility of metal-oxide clusters is emphasized from aspects of endocytosis, macropinocytosis, and phagocytosis. Through the classification of late and early transition metals oxide clusters, recent outcomes of light-guided nanoagents are represented with their intriguing chemical and optical properties in their diagnosing and photochemotherapy performance. It shed light on the summary of next generation multifunctional cancer targeting agents’ developments as well as outlook of materials selection trends and research direction in the future.