Harvesting stem cell exosomes from herringbone microfluidic bioreactor for wound healing

Stem cell exosomes have attracted increasing attention in effective wound treatment, while their mass production are still challenging. In this paper, we proposed a novel herringbone microfluidic bioreactor with cell microcarriers integration for batch-preparation of stem cell exosomes. The microfluidic device was designed with parallel herringbone microgrooves on the top and a microcolumn array at the bottom, which provided a controllable fluidic environment for stem cells culturing on the gelatin methacryloyl (GelMA) microcarriers and for exosomes secretion from these cells. Thus, it was demonstrated that the yield of exosomes by this bioreactor was much higher compared with traditional flask cell culture. Besides, bone mesenchymal stem cells (BMSCs) exosomes harvested from the bioreactor under fluidic stimulation expressed an excellent promoting effect on wound healing. These features indicated that the present microfluidic chip integrated with microcarriers possesses great potential for harvesting exosomes for different biomedical applications.