Nanotechnology-Enabled Drug Delivery Systems: Molecular Design, Therapeutic Applications, and Future Perspectives

Abstract

Nanotechnology-enabled drug delivery systems offer new ways to improve the solubility, stability, targeting, release, and intracellular transport of therapeutic agents. This review examines how molecular composition, particle size, morphology, surface charge, rigidity, drug–carrier interactions, and surface functionalisation shape nanocarrier behaviour across biological environments. Major lipid-based, polymeric, inorganic, biological, biomimetic, and hybrid platforms are compared in relation to payload compatibility, pharmacokinetics, pharmacodynamics, and therapeutic performance. The review also evaluates passive and active targeting, biological barrier navigation, organelle-specific delivery, and stimuli-responsive release. Applications are discussed across cancer, infectious disease, vaccination, neurological disorders, cardiovascular and metabolic conditions, inflammatory and autoimmune diseases, and ocular, pulmonary, and transdermal therapy. Particular attention is given to the delivery of proteins, peptides, messenger RNA, small interfering RNA, microRNA, monoclonal antibodies, and genome-editing components. Despite major advances, clinical translation remains limited by variable protein corona formation, immune responses, toxicity, formulation instability, manufacturing complexity, inconsistent scale-up, and regulatory uncertainty. Future progress will depend on standardised evaluation, predictive human-relevant models, biomarker-guided treatment, artificial intelligence-assisted design, biodegradable materials, and continuous manufacturing. Integrating molecular engineering with pharmacological performance, safety, clinical need, and industrial feasibility is essential for converting advanced nanocarriers into reliable and accessible pharmaceutical products with measurable therapeutic advantages over conventional formulations and clear benefits for diverse patient populations in clinical practice.