Abstract
Polymer nanoparticles (PNPs) are compact particulate systems typically ranging from 10 to 1000 nm in size and have emerged as versatile platforms in modern biomedical research. Their growing importance stems from a unique combination of physicochemical properties, including tunable size, surface functionality, high drug loading capacity, and favourable biocompatibility. These features enable PNPs to act as efficient matrix carriers capable of encapsulating, protecting, and co-delivering a wide variety of therapeutic agents, including small molecules, proteins, and nucleic acids, within a single targeted delivery system. One of the key advantages of PNPs lies in their ability to improve both pharmacokinetic and pharmacodynamic profiles of drugs. By controlling drug release, enhancing solubility of poorly water soluble compounds, and reducing premature degradation or clearance, PNP-based systems can increase therapeutic efficacy while minimizing systemic toxicity. Targeting ligands can be incorporated on the nanoparticle surface to promote site-specific drug delivery, further improving treatment outcomes. A range of preparation techniques has been developed for the fabrication of advanced PNPs. These methods are generally classified according to the underlying particle formation mechanism, including polymerization-based approaches that generate nanoparticles directly and techniques that utilize preformed polymers. Advances in nanotechnology and polymer chemistry have enabled precise control over nanoparticle composition, morphology, and surface characteristics, leading to the development of sophisticated colloidal drug delivery systems. The integration of diverse nanomaterials into PNP formulations has further expanded their functional scope, significantly influencing the pharmacological and biopharmaceutical behavior of encapsulated drugs. Owing to their biocompatibility and design flexibility, PNPs have found broad applications in the treatment of cancer, neurodegenerative diseases, central nervous system disorders, and other complex medical conditions. This review elaborates on these aspects, highlighting the potential of PNPs as adaptable and powerful tools in next-generation therapeutic strategies.