Exosomes are extracellular vesicles produced by all cells with a remarkable ability to efficiently transfer genetic material, including exogenously loaded siRNA, to cancer cells. Here, researchers at MD Anderson Cancer Center report on a bioreactor-based, large-scale production of clinical-grade exosomes employing good manufacturing practice (GMP) standards. A standard operating procedure was established to generate engineered exosomes with the ability to target oncogenic Kras (iExosomes). The clinical-grade GMP iExosomes were tested in multiple in vitro and in vivo studies to confirm suppression of oncogenic Kras and an increase in the survival of several mouse models with pancreatic cancer. The researchers perform studies to determine the shelf life, biodistribution, toxicology profile, and efficacy in combination with chemotherapy to inform future clinical testing of GMP iExosomes. Collectively, this report illustrates the process and feasibility of generating clinical-grade exosomes for various therapies of human diseases.
GMP-grade production of MSC-derived exosomes
(A) The number of exosomes, quantified by NanoSight, produced by 6 consecutive 48-hour isolations (harvests) of MSC-conditioned media from the bioreactor. (B) Particle size distribution analysis using NanoSight. (C) Correlation between the number of exosomes and exosomal protein from the bioreactor harvests (Pearson correlation test). Data shown in A–C are representative of the same data, obtained from the same bioreactor experiment (Bioreactor run 1) (see also Supplemental Figure 5A). (D) Representative TEM of exosomes from each of the 6 consecutive bioreactor harvests. Scale bar: 100 nm.