Engineering exosomes for cancer therapy - Modification technologies and subcellular targeting strategies: A review

Exosomes are secreted lipid bilayer vesicles of 30-150 nm in diameter. Their low immunogenicity, excellent biocompatibility, and inherent targeting capability make them a promising drug delivery vehicle for cancer therapeutics. However, the use of natural exosomes is still challenging for therapeutic applications, including limited targeting precision and drug-loading efficiency, necessitating engineered modification strategies to optimize their performance. To further enhance exosome targeting capacity, recent studies have explored precision delivery strategies targeting subcellular structures such as lysosomes, nuclei, mitochondria, and the endoplasmic reticulum, thereby improving exosome therapeutic potential. This review systematically summarizes the core advantages of exosomes as drug carriers, elaborates on their engineering modification methods, and highlights recent advances in strategies to improve exosomes targeting of subcellular structures to enhance antitumor efficacy. The review aims to provide a theoretical foundation and technical guidance for developing exosome-based precision therapies for cancer.