Indocyanine green-loaded exosomes for image-guided glioma nano-therapy

Abstract Glioblastoma multiforme (GBM) is the most aggressive and deadliest type of brain tumor with a > >th he most aggressive and deadliest type of brain tumor witnear-infrared fluorescent dye, but it is hard to directly target brain tumor. Therefore, our study aimed to develop a new carrier for ICG to accurately visualize cancer tissue during surgery. Exosomes were isolated from culture U-87 MG cells, then loaded with Indocyanine green (ICG) and conjugated with RGERPPR peptide (RGE) (R-exo-ICG). The parameters of R-exo-ICG were analyzed and injected into tumor-bearing nude mice to evaluate its anti-tumor effect. R-exo-ICGs were nano size, and completely released ICG within 24 h. RGE modification increased cell uptake of exosomes, and induced cell apoptosis through activating Caspase 3 signaling pathway after laser irradiation. Moreover, R-exo-ICG was largely accumulated in the brain tumor in vivo, and inhibited tumor growth in tumor-bearing mice. RGE-conjugated exosomes that loaded ICG could target brain tumor in mice and significantly inhibited tumor growth in mice, which suggested that R-exo-ICG might serve as a novel approach for GBM treatment.