Protein Nanoparticles in Drug Delivery: Biocompatibility, Functionalization, and Therapeutic Applications

Due to being biocompatible and biodegradable with a wide variety of structural characteristics, protein nanoparticles (PNPs) can act as novel drug delivery vehicles. PNPs can be constructed from the natural proteins: albumin, gelatin, silk fibroin, casein, and ferritin, thus providing several advantages compared to organic polymers and inorganic materials. PNPs can encapsulate a number of types of therapeutic agents (designed to prevent degradation and premature clearance), like proteins, peptides, nucleic acids and small molecules. Moreover, they have a unique surface chemistry that permits functionalizing with other polymers, ligands for targeting, or biomimetic coatings to achieve enhanced circulation time, tissue specificity and uptake. Finally, some of the many attributes of PNPs include: pharmacokinetic and pharmacodynamics profiles that increase the efficacy of therapeutic treatments while decreasing levels of toxicity to healthy tissues. Current fabrication techniques allow for precise regulation of the size, morphology and release kinetics of the PNPs. Protein nanocarriers have demonstrated potential as delivery systems for genes and vaccines, as well as for antimicrobial treatment, cancer treatment, and regenerative medicine. While protein nanocarriers have many advantages, there are still challenges related to lot-to-lot reproducibility, stability, and large-scale manufacturing of the carrier system. This review highlights recent advancements made in regard to the design of protein nanoparticles, their biocompatibility, their functionalization methods, and their therapeutic uses; these advancements demonstrate that protein nanoparticles could potentially serve as safe, efficient, and readily translatable drug delivery systems in the future.