The application and modification of biocompatible and biodegradable natural polymers, specifically alginate, cellulose, chitosan, collagen, dextran, fibrin, gelatin, and hyaluronic acid, are crucial to providing promising therapeutic effects appropriate to physiological conditions. In this case, natural polymers have been shown to be more acceptable than other biomaterials to obtain effective novel micro- and nanoformulations. However, there are some clinical limitations, such as low water solubility and half-life, which may be improved by formulations of these biomaterials with synthetic polymers, specifically in the nanoscale. To this end, this review has explored both advances and limitations in biopolymer applications in bio-scaffolds, medical implants, and micro- and nanoformulations of therapeutic agents for treating neurodegenerative diseases, diabetes, cancer, and microbial infections.
