Chemotherapeutic Loading and Delivery of Patient-Derived Extracellular Vesicles Are Influenced by Colorectal Cancer Disease Stage and Protein Corona

Background/Objectives:

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with poor outcomes in advanced stages and significant limitations in current chemotherapy regimens due to systemic toxicity. Extracellular vesicles (EVs) have emerged as promising natural drug delivery vehicles, offering the potential for targeted, less toxic therapies. This study investigates the feasibility of using autologous, patient-derived EVs as a delivery system for the chemotherapeutic agent doxorubicin, focusing on how disease stage and the EV protein corona influence loading and delivery efficiency.

Methods:

EVs were isolated from plasma and tissue samples of CRC patients at different disease stages, as well as from healthy controls, demonstrating successful isolation and characterisation of EVs, with distinct profiles across different sources.

Results:

Doxorubicin loading into EVs was significantly higher in CRC patient-derived EVs compared to healthy controls, and tissue-derived EVs yielded higher quantities of drug-loaded particles. Delivery of doxorubicin-loaded EVs to recipient CRC cell lines (SW480 and SW620) revealed that disease stage impacts both EV uptake and drug delivery, with late-stage EVs showing reduced uptake and delivery efficiency. The protein corona, known to coat circulating EVs, was found to influence drug loading and delivery. Pre-treatment of cell line-derived EVs with plasma proteins enhanced EV uptake but reduced doxorubicin loading and subsequent delivery, particularly when using plasma from healthy volunteers.

Conclusions:

These findings underscore the importance of EV source and protein corona composition in optimising drug delivery strategies. Our results suggest that autologous, patient-derived EVs hold potential as a targeted drug delivery system for CRC, but highlight the need for further optimisation of EV isolation, loading methods, and understanding of how disease progression affects EV functionality. This approach could ultimately reduce systemic toxicity and improve therapeutic outcomes for CRC patients.