Review on bio-selenium nanoparticles: Synthesis, protocols, and applications in biomedical processes

Abstract Selenium, a vital trace element for all living beings, significantly contributes to metabolic processes. In the past two decades, owing to their excellent bioavailability, low toxicity, and compatibility with living organisms, selenium nanoparticles (SeNPs) have gained significant attention in the realm of biological applications. SeNPs can be formed through various techniques, but biologically synthesized SeNPs have superior biocompatibility with living systems. Moreover, biosynthesized SeNPs (bio-SeNPs) have been proven to have superior antioxidant, antiproliferative, and immunostimulatory potential compared with SeNPs produced using both chemical and physical techniques. The primary aim of this overview article is to focus on bio-SeNPs derived from several biological sources, including bacteria, algae, fungi, and plants, and highlight key biological and medical roles, such as antidiabetic, antimicrobial, hepatoprotective, immunostimulating, protection against oxidative damage, and chemotherapeutic properties.