Exosomes as Precision Nanocarriers: A Next-generation Approach to Targeted Cancer Therapy

Exosomes, nanosized extracellular vesicles (30-150 nm) secreted by almost all cell types, have emerged as promising natural nanocarriers for precision drug delivery in cancer therapy. Their unique biological properties-including inherent biocompatibility, stability in circulation, ability to traverse biological barriers such as the blood-brain barrier, and intrinsic cell-targeting potential-position them as superior alternatives to synthetic nanoparticles. This review critically explores recent advances in exosome-based drug delivery systems, emphasizing their biogenesis, isolation technologies, and engineering strategies for enhanced therapeutic cargo loading, targeting, and controlled release. We highlight cutting-edge approaches employing exosomes to deliver chemotherapeutics, siRNA, and microRNAs for tumor-specific therapy, alongside their role in modulating tumor angiogenesis, immune responses, and drug resistance mechanisms. Furthermore, the review discusses current translational challenges, including heterogeneity in exosome populations, scalability of production, standardization of isolation and characterization methods, and safety concerns in clinical applications. Finally, we provide future perspectives on integrating exosome-based therapies with next-generation nanomedicine and immunotherapy platforms to achieve personalized, targeted, and minimally invasive cancer treatment. Harnessing the natural advantages of exosomes may pave the way toward clinically viable, precision-engineered nanomedicines capable of revolutionizing oncology therapeutics.