Protein Nanoparticles: Promising Platforms for Drug Delivery Applications

The development of drug delivery systems using nanoparticles as carriers for small and large therapeutic molecules remains a rapidly growing area of research. The advantages of using proteins to prepare nanoparticles for drug delivery applications include their abundance in natural sources, biocompatibility, biodegradability, easy synthesis process, and cost-effectiveness. In contrast to several particulate systems like nanoparticles from metallic and inorganic/synthetic sources, the protein nanoparticles do not have limitations such as potential toxicity, large size, accumulation, or rapid clearance from the body. In addition, protein-based nanoparticles offer the opportunity for surface modification by conjugation of other protein and carbohydrate ligands. This enables targeted delivery to the desired tissue and organ, which further reduces systemic toxicity. The use of protein nanoparticles for such applications could therefore prove to be a better alternative to maneuver and improve the pharmacokinetic and pharmacodynamic properties of the various types of drug molecules. In this review, while focusing on the properties of a few proteins such as the silk protein fibroin, we attempt to provide an overview of the existing protein-based nanoparticles. We discuss various methods for the synthesis of this class of nanoparticles. The review brings forth some of the factors that are important for the design of this class of nanoparticles and highlights the applications of the nanoparticles obtained from these proteins.