From conventional to cutting-edge: Exosomes revolutionizing nano-drug delivery systems

To address challenges encountered by conventional drug delivery systems (DDS) such as easy degradation, poor utilization, and low loading rates, researchers have been endeavoring to develop novel nano-DDS for several years. However, most current nano-DDS are synthesized from non-carbon-based biomaterials in vitro, leading to issues with lower biocompatibility and in vivo metabolic toxicity. There is therefore an urgent need for a drug delivery material that surpasses both conventional DDS and existing nano-DDS to meet optimal drug delivery requirements. Exosomes (Exos) are nanoscale extracellular vesicles secreted by various cells, sourced from carbon-based biological origins with excellent biocompatibility and low immunogenicity. Their nanoscale size and surface-specific recognition proteins enable advantages such as targeted drug delivery, controlled local release, and resistance to degradation. Moreover, serving as intercellular messengers in normal physiological processes, Exos are increasingly investigated for novel nano-DDS applications. However, challenges remain regarding drug loading capacity, potential side effects, and safety in biomedical applications, which somewhat restrict their widespread use. This review systematically summarizes the biological origin and functions of Exos, their transformative impact on traditional DDS, the advancement of novel nano-DDS, and discusses the significant advantages and potential limitations of Exos in drug delivery. It underscores Exos’ superiority as a novel DDS over traditional and other nano-DDS, highlighting their efficient, safe, and sustainable attributes, while acknowledging critical considerations for their application in the burgeoning field of nanomedicine.