Functionalized nanoclays in bioactive materials

The therapeutic potential of natural clays has long been known and used as a remedy for various ailments. Due to their thin layered structure, charged, biocompatiblity and specific compositions, nanoclays are an emerging class of two-dimensional (2D) biomaterials of interest. Nano-layered silicates, are gaining ground due to their unique properties, including tunable surface chemistry, controlled drug release, chemical stability, high elastic modulus, efficient adsorption and good cation exchange capacity. The members of the nanoclay family can be easily functionalized, which significantly improves the mechanical performance of nanocomposites and offer bioactive capabilities. These nanoclays have been investigated for various biomedical applications, including drug carriers for antibiotics, antihypertensives, antipsychotics and anticancer drugs. Due to their non-toxicity, they have also been explored for wound healing, bone cement, tissue engineering and enzyme immobilization. Further, nanoclays have the potential to contribute significantly to the advancement of diagnostic technologies, personalized and regenerative medicine. Therefore, the primary objective of this review is to present an up-to-date scenario of recent breakthroughs in understanding the classification of nanoclay, nanocomposites, their application in various biomedical fields, and the effect of nanoclay on cellular responses. In addition, new and emerging applications and potential avenues for research will be highlighted. Nanoclay has been the subject of extensive investigation in various fields, and biomedical research makes up the majority. In this review, different applications of nanoclay have been discussed viz., development of diagnostic tools in form of sensors, enzyme immobilizers, targeted drug delivery systems, and cementing material for tissue and bone engineering.