2D layered nanomaterials for therapeutics delivery.

Two-dimensional (2D) nanomaterials are ultrathin, layered materials with a high surface-to-volume ratio that can deliver various therapeutics including small-molecule drugs, peptides, and large proteins. Their high surface area allows for high therapeutic loading and sustained therapeutic release over time. Some 2D nanomaterials respond to external stimuli, providing control over triggered or on-demand therapeutic release. 2D nanomaterials explored for biomedical applications include carbon-based (graphene), nanoclays, black phosphorous, layered double hydroxides, metal organic frameworks, covalent organic framework, 2D metal carbides and nitrides, transition metal dichalcogenides, transition metal oxides, polymer nanosheets, and hexagonal boron nitride. Most of these nanomaterials are biocompatible and degrade into nontoxic products, which is advantageous for therapeutic delivery systems. In this article, we will evaluate these nanomaterials for therapeutic delivery. We will highlight some of their unique physical and chemical characteristics, discuss their biological stability, and investigate their ability to deliver various therapeutics. Recent developments in 2D nanomaterials as drug delivery systems will also be discussed.