Specific Binding of Cancer-derived Exosomes to Synthetic Carbon Beads – Implication for Adjuvant and Neoadjuvant Cancer Treatment

Extracellular vesicles (exosomes) can mediate intercellular communication. In cancer patients, exosomes are central to intercellular communication between cancer cells and non-malignant cells within the tissue niche, and at distant regions. This type of communication influences the biology of the cancer and treatment response. This study tested the hypothesis that carbon beads, 150–500 μm in size with pore size about 27 nm, can capture exosomes from the plasma of cancer patients, and from a glioblastoma cell line (T98G). The challenge to addressing the hypothesis is the relatively larger size of exosomes, 50–120 nm, to be captured within the carbon pore. This study tested plasma from a patient with ovarian cancer and two breast cancer patients, HER2+ and triple negative for hormone receptor (TNBC), and released exosomes from T98G cells. This study showed exosomes from ovarian plasma binding to a specific synthetic carbon, C529. Similar binding did not occur with plasma from age-matched healthy controls. GBM exosomes also bound to C529 but the repertoire of carbon was broader. TNBC exosomes showed low affinity for the identified carbon. However, exosomes from HER2+ breast cancer were able to bind to the carbon beads. In total, this study showed binding of exosomes from cancer plasma to C529 carbon. The results of these findings are discussed in the context of potential treatment, and they provide future direction for studies to examine carbon beads as adjuvant or neoadjuvant treatment for cancer.