The Application of Engineered Exosomes in Tumour Therapy: Challenges and Prospects from Design to Clinic

Exosomes are nanoscale extracellular vesicles naturally secreted through the endosomal pathway. It plays a vital role in intercellular communication, appearing as promising nano-carriers for cancer therapy. Advantages include low immunogenicity, biocompatibility, natural targeting ability, and capacity to cross biological barriers, making them attractive platforms for precision oncology. Recent advances in nanotechnology and synthetic biology have enabled the engineering of exosomes to enhance drug loading, targeting specificity, and therapeutic efficacy. Strategies include endogenous loading by modifying donor cells and exogenous loading through biological or chemical manipulation. Despite their promise, challenges remain in large-scale production, standardisation, quality control, and in vivo pharmacokinetics. Innovative purification techniques such as microfluidic immunochips have enhanced isolation efficiency and diagnostic capabilities. Clinical applications of engineered exosomes are expanding, with early trials demonstrating their potential in drug delivery, reversing drug resistance, and cancer vaccination. These findings underscore the potential of engineered exosomes as a next-generation multifunctional therapeutic platform. This paper reviews the latest developments in the design, engineering, purification, and clinical application of exosomes in oncology, highlights current challenges, and discusses prospects for their translation into clinical practice.