Isolation and Identification of Adipose Stem Cell Exosomes and the Study of Its Potential as Drug Delivery Carrier In Vitro

Most small molecule anticancer drugs have high lipophilicity and low water solubility, which is often regarded as a key obstacle to their development and clinical applications. A variety of nano-size drug carriers, like liposomes, has been developed for solubilizing these drugs. Naturally secreted by cells, exosomes have good biocompatibility and are considered as “natural liposomes.” Exosomes released by mesenchymal stem cells (MSCs) not only have the properties like the ones generated by other cells but may also possess many therapeutic bioactive factors uniquely secreted by stem cells. In the present study, exosomes secreted by murine adipose stem cells (mASCs) were isolated, identified, and characterized. Its potential as drug delivery carrier and its biological effects on hepatoma cells and normal liver cell lines were explored in vitro. The data indicated that mASC exosomes separated by our improved sequential filtration method have particle size distribution in 30–150 nm, positively expresses TSG101, CD63, CD9, GADPH, and negatively expresses calnexin. The exosomes of mASCs obtained by this method could be taken up by cells and inhibit the cell activity of hepatoma cells HepG2, while enhance the normal cell activity of THLE-2. The results suggest that ASC exosomes are ideal potential drug delivery carriers and have the prospect of applications in carcinoma treatments.