Prussian Blue Nanoparticle: From a Photothermal Conversion Agent and a Drug Delivery System, to a Bioactive Drug

Nanomedicine is an interdisciplinary science that involves chemistry, materials, physics, engineering, biology, and medicine. The main focus of nanomedicine is on drug carriers: how to improve drug efficacy and reduce side effects. In order to further improve the synergistic and detoxifying effects of nanomedicines, scientists have adopted a multifunctional integration strategy. However, versatility brings complex components and ignores the synergistic effects between components. The lack of in-depth research on the bioactivities of nanocarriers hinders the development and clinical translation of nanomedicine. In the past decade, scientists have gradually discovered that nanomaterials show excellent bioactivities, becoming an enormous treasure trove for disease prevention and treatment. Among numerous bioactive materials, Prussian blue (PB) is a clinical antidote approved by the US Food and Drug Administration, showing excellent biosafety. However, clinically approved PB owns many drawbacks, and it is difficult to satisfy the requirements of disease prevention and treatment. When the size reduces to the nanoscale, nano PB shows both unique properties of nanomaterials and the enhancement of its performance and bioactivities. Due to its easy-to-regulate structure and rich iron suspended bonds, nano PB may be a potential drug delivery system. Electron transition in the Fe-CN-Fe structure endows nano PB with strong absorbance in the near-infrared region, becoming a potential photothermal conversion agent. Furthermore, due to its rich redox potential and catalytic activities, nano PB may be a bioactive drug with a great translational clinic prospect. In this Account, we describe our exploration of nano PB as a photothermal conversion agent, a drug delivery system and a bioactive drug in the prevention and treatment of disease over the past decade. We first summarize the application of nano PB as a photothermal conversion agent and a drug delivery system in the treatment of cancer, and then focus on our recent progress in the application of nano PB as a bioactive drug in the prevention and treatment of diseases (such as tumors, neurodegeneration, cerebrovascular disease, bone-related degenerative disease, gastrointestinal disease, and skin lesions). Finally, we look forward to the open challenges and future developments in this rapidly developing field. We hope this Account will help readers understand nano PB not only as a photothermal conversion agent and drug carrier but also as a bioactive drug, thus realizing its great potential in disease prevention and treatment. These studies also provide a research paradigm for bioactive nanomaterials. As our and other teams continue to explore this promising material, the unique characteristics of bioactive nanomaterials represented by nano PB may bring further exciting developments in disease prevention and treatment.