Targeted Drug Delivery Using Niosomes: Progress, Obstacles, and Future Directions

Niosomes are carriers that contain non-ionic surfactants in a vesicular form that have been presented as an innovative drug-delivery system of significant versatility due to their structural stability, biocompatibility, and drug loading capacity with various therapeutics. When comparing niosomes to standard liposomes, niosomes exhibit an enhanced physical and chemical stability, cost-effectiveness, and facility for a large-scale manufacture to be both clinically and industrially-relevant. Recent advances in formulation techniques focused on cholesterol, charge inducers, and newer surfactant combinations have initiated new methods of modulating vesicle-size, bilayer rigidity, and loading of attachment drugs, respectively. In addition, surface modifications of niosomes with ligands such as monoclonal antibodies, peptides, aptamers and folic acid, have greatly improved the ability to actively target cellular receptors, further providing site-specific delivery with improved therapeutic efficacy and a decreased potential for systemic toxicity. The inclusion of stimuli-responsive components such as pH-sensitive polymers, redox-reactive linkers, and thermoresponsive lipids have also afforded the development of smart niosome systems to trigger drug release according to pathological indicators. These characteristics have enabled niosomal applications across diverse disease models, such as solid tumors, fungal and bacterial infections, dermatological diseases, and neurological disorders. Apart from these encouraging characteristics, various translational challenges are still present, such as instability of the vesicles during storage, quick clearance in vivo, batch-to-batch reproducibility, and regulatory ambiguities. Novel strategies like PEGylation, freeze-drying, hybridization with biodegradable polymers, and utilization of scalable processes are being explored to resolve these issues. This review provides an integrative overview of recent research directions, challenges, and prospects of niosome-based targeted delivery, highlighting technological advancement as well as translational relevance. The observations made in this review will be useful for researchers, formulation scientists, and drug developers aiming to develop next-generation, patient-specific nanocarrier systems with superior specificity, safety, and clinical relevance.