Therapeutic Potential of Protein-Based Polymers as Nanocarriers for Drug Delivery.

INTRODUCTION/OBJECTIVE: Protein-based polymeric nanocarriers are increasingly being investigated as biodegradable, biocompatible systems for drug and gene delivery. This review critically examines major protein-based polymeric nanocarriers and globular proteins, including casein, gelatin, gliadin, collagen, elastin, albumin, silk fibroin, lectins, legumin, ferritin, zein, virus-like particles, silk-like polypeptides, elastin-like polypeptides, and silk-elastin-like protein polymers. METHODS: Relevant studies were identified from major scientific databases using search terms related to protein-based polymeric nanocarriers, drug delivery, protein nanoparticle, recombinant protein polymer, ferritin nanocages, and virus-like particles. Studies were considered if they discussed carrier design, formulation methods, physicochemical characterization, biological performance, clinical translation, patents, or recent developments in protein-based delivery systems. RESULTS: Protein-based polymeric nanocarriers can be classified into five main structural classes: protein nanoparticles, protein micelles, protein nanocages, recombinant protein polymer assemblies, and protein-drug conjugate or fusion systems. Albumin-based nanoparticles remain the most clinically advanced platform, whereas ferritin nanocages and virus-like particles provide structurally defined systems for receptor-mediated targeting. Plant-derived proteins such as casein, zein, and gliadin form polymeric matrices relevant for oral delivery, whereas silk fibroin, collagen, gelatin, and recombinant protein polymers self-assemble into structures that support sustained, local, and stimulus-responsive delivery. DISCUSSION: Despite their potential, protein-based polymeric nanocarriers face several challenges, including protein corona formation, immunogenicity, storage instability, batch variability, scale-up limitations, and regulatory uncertainty. CONCLUSION: Future development should prioritize reproducible manufacturing, safer surface modification, improved stability, and rigorous evaluation of immune responses and translational feasibility.