Morphological and physicochemical characteristics, biological functions, and biomedical applications of diatom frustule

Abstract

Diatoms are the most important contributors to marine primary production, and their most distinctive feature is the silicified cell wall, known as frustule. Recent years, abundant evidences demonstrate that frustule is essential for diatoms metabolic activities, such as nutrients uptake, protection against ultraviolet radiation, deterrent to predation, resistance to parasites, light harvesting, CO2 capture, and position control. Besides that, due to the uniform composition of silica, internal hollow structure, multilayer porous valve, high thermal stability, and functionally active surface, frustule, as the most exquisite biosilica in the earth, also shows huge potentiality in biomedical field serving as promising bionanomaterials. Considering that the architecture features and physicochemical properties of frustule underlie its biological functions and biomedical applications, therefore, this review starts from the morphological and physicochemical characteristics, and then introduces the biological functions and biomedical applications of the frustule.