Microfluidic isolation of highly pure embryonic stem cells using feeder-separated co-culture system

Engineered artificial tissues from stem cells show great potential in regenerative medicine, disease therapies and organ transplantation. To date, stem cells are typically co-cultured with inactivated feeder layers to maintain their undifferentiated state, and to ensure reliable cell purity. Herein, we propose a novel microfabricated approach for feeder-separated coculture of mouse embryonic stem (mES) cells on polydimethylsiloxane (PDMS) porous membrane-assembled 3D-microdevice. Normal mouse embryonic fibroblasts (mEFs) without inactivation were specifically co-cultured with mES cells, resulting in the formation of mES cell colonies on spatially controlled co-culture with feeder layers. An excellent undifferentiated state was confirmed by the expressions of Nanog, octamer binding protein 4 (Oct-4) and alkaline phosphatase (ALP) after 5 days culture. As a result, with the significant advantages of efficiency and simplicity, pure mES cell populations (a purity of 89.2%) from mEFs co-cultures were easily collected without any further purification or separation.