Nanoparticles in Targeted Cancer Therapy: Current Platforms, Resistance-Modulating Mechanisms, Clinical Translation, and Future Challenges

Cancer is one of the leading causes of death and morbidity, with a complicated pathophysiology. There are several conventional cancer therapies, including chemotherapy, radiation therapy, and immunotherapy. However, there are major challenges to effective cancer treatment, including cytotoxicity, lack of selectivity, and multidrug resistance. Nanoparticle-based drug delivery methods have emerged as an effective method to circumvent these constraints by facilitating targeted and precisely controlled drug delivery. Considering all of these facts, there has been a huge increase in demand in recent years for the development of innovative approaches for effective cancer treatment. Nanoparticles not only solve the limitations of conventional cancer therapy but also overcome multidrug resistance. The literature review illustrates that nanoparticles may accumulate in tumour tissues through the Enhanced Permeability and Retention (EPR) effect caused by abnormal tumor vasculature and impaired lymphatic drainage. Still, the degree of EPR-mediated accumulation varies significantly among patients and tumor types, and it may be less predictable in clinical circumstances than pre-clinical research implies. Ligand-mediated active targeting can enhance cellular uptake, whereas nanoparticle-based drug delivery methods may improve drug bioavailability, minimize systemic toxicity, and also help in overcoming multidrug resistance. In spite of these improvements, challenges related to stability, scalability, clinical translation, and regulatory approval remain substantial. Future advances in nanoparticle design and precision nanomedicine are expected to accelerate the development of safer, more efficient, and clinically feasible targeted cancer therapy.