Natural and Synthetic Clay Minerals in the Pharmaceutical and Biomedical Fields

Clay minerals are historically among the most used materials with a wide variety of applications. In pharmaceutical and biomedical fields, their healing properties have always been known and used in pelotherapy and therefore attractive for their potential. In recent decades, the research has therefore focused on the systematic investigation of these properties. This review aims to describe the most relevant and recent uses of clays in the pharmaceutical and biomedical field, especially for drug delivery and tissue engineering purposes. Clay minerals, which are biocompatible and non-toxic materials, can act as carriers for active ingredients while controlling their release and increasing their bioavailability. Moreover, the combination of clays and polymers is useful as it can improve the mechanical and thermal properties of polymers, as well as induce cell adhesion and proliferation. Different types of clays, both of natural (such as montmorillonite and halloysite) and synthetic origin (layered double hydroxides and zeolites), were considered in order to compare them and to assess their advantages and different uses.