Nanosized Cerium Phosphate: Synthesis Methods, Morphology, and Potential Applications in Biomedicine

The growing field of nanobiotechnology could provide an alternative platform for the development of new therapeutic agents. A potential means for achieving these goals are nanoparticles of rare-earth metals, for example, nanoceria. According to the results of numerous in vitro and in vivo studies, not only oxide forms of lanthanides can demonstrate a pharmacological effect. A promising nano-object for biomedical application is cerium phosphate, which exhibits both properties characteristic of cerium dioxide and its own unique properties, due to the diversity of morphology. However, at present, a unified methodological approach has not been formulated that would make it possible to formulate principles for obtaining a compound with specified properties. This review was conducted on using the international databases PubMed, PubChem, Scopus and Google Scholar, and included original studies and reviews. The literature describes the preparation of cerium phosphate nanoparticles by the hydrothermal, chemical precipitation, microwave, and sol-gel methods. It was established that reaction temperature, pH value of the medium, use of organic solvents, ratio of reagents, and precursors have a direct influence on the size, shape, and structure of the obtained nano-object, making it possible to synthesize nanospheres, nanorods, and nanoneedles by regulating these parameters. In addition, the strategy of obtaining nano-objects with specified properties can be implemented by using excipients of predominantly polymer nature. The use of auxiliary substances is capable both of exerting a stabilizing effect and improving adherence to the nanoscale range, and of influencing pharmacological activity. The literature describes the possibility of using cerium phosphate as a redox-active, regenerative, antibacterial, sunscreen, and antitumor agent. However, the insufficient amount of data on the toxicological profile, as well as the results of in vivo studies, remains a significant limitation for the introduction of cerium phosphate into clinical practice. Thus, the purpose of the present review is to identify patterns that make it possible to formulate recommendations for the synthesis of cerium phosphate with specified properties, to assess factors affecting its suitability for use in biomedicine, and to consider its prospects and limitations.