Purified exosomes are bioactive

MSCs are uniques in that they do not express certain cellular marker antigens and thus manage to evade attack by the immune system. This ability means that they could be administered therapeutically. Exosomes secreted by MSCs share this same property and may also be used in vivo without needing to suppress the recipient's immune system. Additionally, MSCs and their exosomes have been observed to be drawn towards damaged tissue and assist in repair. Engineering MSC-derived exosomes could potentially be a method of delivering biomolecules to target disease.

Based on previous findings (McCready J., et al., 2010), adipocyte-derived mesenchymal stem cell exosomes when added to cells in a wound healing assay accelerate the wound healing process. To model this study, MDA-MB-231 breast cancer cells were seeded in a 6 well culture dish and allowed to grow to 80% confluency. The cell monolayer was wounded vertically using a sterile 1 ml pipet tip to create a clear area depleted of cells. This is referred to as the "wound" in the wound healing or scratch assay. After the wound was introduced, images of the cells adjacent to the wound were captured immediately, then after 2 and 4 hours. Control cells were treated with PBS, and test cells were treated with exosomes isolated from adipocyte-derived mesenchymal stem cells (about 3x10^11 exosomes). The data below show that SBI's adipocyte-derived mesenchymal stem cell purified exosomes (cat# EXOP-140A-1) are bioactive and also mediate the acceleration of wound healing in this assay.