Biomedical applications of cationic clay minerals

Clay minerals have been a subject of interest owing to their ready availability in nature, a wide range of applications in various industries, and particularly their current and potential biomedical applications. They have been widely used for curative and protective purposes by humans since ancient times. Cationic clay minerals possess specific physicochemical characteristics such as high surface reactivity (high adsorption, cation exchange, colloidal or swelling capacity), good rheological behavior, high acid-absorbing capacity, and high dispersibility in water, which renders them suitable for various biomedical applications. Only a few reviews have exclusively discussed the biomedical applications of clay minerals, and to our knowledge, there is no updated review focusing on cationic clay minerals and their applications in pharmaceuticals, cosmetics, and regenerative medicine. In this review, we provide a brief introduction on natural, synthetic, and hybrid cationic clay minerals followed by a detailed discussion about their applications in biological systems.