Current trends in exosomes as therapeutic drug delivery systems

Exosomes have garnered significant interest in biomedical research due to their potential therapeutic applications. They are extracellular vesicles secreted by cells, distinguished by a lipid bilayer membrane that encases various biological substances, including nucleic acids and proteins, within their lumen or lipid bilayer. They offer several advantages, like superior compatibility and targeted delivery capability, enabling innovative therapeutic development and efficient drug transport across cellular barriers, including the BBB. They also provide long circulation times, low toxicity, and protection from degradation. They play critical roles in cell communication, tissue repair, facilitating immune response, modulating inflammation, homeostasis, transferring molecules between cells, and specifically homing to tumor sites. Techniques such as microfluidic-based isolation and surface modification are advancing the production of clinical-grade exosomes. Exosomes have shown potential in delivering drugs for a wide range of diseases, including cancer, neurological disorders, infectious diseases, and cardiovascular issues. Challenges such as low yield during isolation, difficulty in large-scale production, heterogeneity of exosome populations, and maintaining stability during storage hinder their practical use. Multidisciplinary research is needed to overcome these limitations and unlock their potential in early disease detection and therapy, with future applications expected in advanced drug delivery, diagnostic biomarkers, and disease prognosis. Regulatory considerations, including rigorous preclinical and clinical trials, are crucial for translating these innovations into approved therapies. This review highlights the emerging development of exosomes in therapeutic drug delivery systems. The loading technique is discussed in a detailed manner through which the drugs are attached to exosomes and delivered to the target site.