Nanocarriers in Drug Delivery: Advances in Targeting Mechanisms, Therapeutic Applications, and Future Perspectives

Nanocarriers have emerged as a transformative approach in modern drug delivery systems, addressing the limitations of conventional therapeutic methods such as poor bioavailability, lack of specificity, and systemic toxicity. These nanoscale systems, typically ranging from 1 to 1000 nm, enable efficient drug encapsulation, controlled release, and targeted delivery to diseased tissues. The mechanisms of drug targeting passive, active, and stimuli-responsive—are discussed in detail, highlighting their role in enhancing therapeutic efficacy and minimizing off-target effects. Furthermore, the wide-ranging applications of nanocarriers in cancer therapy, neurological disorders, infectious diseases, ocular delivery, gene therapy, and vaccine delivery are explored. Despite their important rewards, trials such as toxicity concerns, stability issues, large-scale manufacturing difficulties, and regulatory barriers remain critical obstacles to clinical translation. Recent advances, including smart nanocarriers, hybrid systems, biomimetic approaches, and AI-assisted formulation design, are paving the way for next-generation nanomedicine. Future perspectives emphasize the role of nanocarriers in precision medicine, multifunctional therapeutics, and improved regulatory frameworks. Overall, nanocarriers represent a promising platform for improving therapeutic outcomes and advancing personalized healthcare.