Role of Pullulan and Pullulan-based Polymeric Nanoparticles in DrugDelivery

The fungus Aureobasidium pullulans produces pullulan, a water-soluble polysaccharide composed of maltotriose units linked by α-1,6 glycosidic bonds. Its unusual physicochemical properties, including high biocompatibility, biodegradability, non-immunogenicity, and ease of chemical modification, make it a promising candidate for creating enhanced drug delivery systems. Pullulan-based polymeric nanoparticles (PNPs) have recently emerged as a promising nanocarrier platform for precise and controlled drug delivery. These nanoparticles can encapsulate a range of pharmaceutical compounds, including small-molecule medications, peptides, proteins, and nucleic acids, thereby improving their stability, solubility, and pharmacokinetic properties. The pullulan backbone's hydroxyl groups serve as reactive sites for functionalisation, allowing the conjugation of targeting ligands (e.g., folic acid, antibodies, peptides), imaging agents, or stimuli-responsive moieties (pH, redox, temperature), enabling site-specific drug delivery and theragnostic applications. Furthermore, their high mucoadhesive properties and ability to cross biological barriers, such as the blood-brain barrier (BBB), enhance their usefulness in challenging therapeutic areas, such as neurological disorders. Despite these promising traits, challenges persist in large-scale production, regulatory approval, and long-term viability. Nonetheless, with ongoing breakthroughs in nanotechnology and polymer chemistry, pullulan-based polymeric nanoparticles provide a feasible and adaptable basis for next-generation drug delivery systems in personalised medicine. This review highlights the significance of pullulan in nanoparticle formulation, discussing its role in stabilizing nanoparticles, controlling drug release, and enhancing biocompatibility. Examine pullulan as a biopolymer for nanoparticle production, detailing its properties, advantages, and potential applications in drug delivery systems.