Capping Agents for Selenium Nanoparticles in Biomedical Applications.

Selenium nanoparticles (Se NPs) have many biomedical applications as both therapeutic agents and delivery systems. The bio-functionality and toxicity of Se NPs are defined by their size, morphology, and surface chemical composition, which are associated with the capping layer on the surface of NPs. Capping agents can modify the characteristics of NPs and make them appropriate candidates for biomedical use. They play a critical role in preventing over-growth and aggregation of NPs, which is one of the major obstacles in NPs preparation. Capping agents stabilize the NPs interface, where is in contact with the surrounding medium and are responsible for the physicochemical and biological properties of NPs. A wide range of compounds with different sources can be used as capping agents for Se NPs synthesis to improve their pharmacokinetics and pharmacodynamics. Each capping agent has its unique characteristics leading to a particular NP formation. In this narrative review, different types of capping agents based on their sources and their effects on physicochemical and biological aspects of Se NPs are discussed. [ABSTRACT FROM AUTHOR]