Controlled release of basic fibroblast growth factor from a water-floatable polyethylene nonwoven fabric sheet for maintenance culture of iPSCs

Basic fibroblast growth factor (bFGF) is an essential supplement for culture media to support the proliferation of human pluripotent stem cells, while preserving their pluripotency. However, it is extremely unstable under cell culture conditions at 37 °C. Therefore, a culture medium supplemented with bFGF needs to be changed every day to maintain an effective concentration of bFGF. This study aimed to create a bFGF-releasing material via simple bFGF adsorption following oxygen plasma treatment by using a water-floatable polyethylene (PE) nonwoven fabric sheet as a bFGF-adsorbent material. Preliminary oxygen plasma treatment enhanced bFGF adsorption onto the sheet by increasing its surface water wettability. Based on the bFGF concentration in the adsorption solution, the resulting bFGF-adsorbed sheet showed different bFGF-release profiles in the culture medium. The bFGF-adsorbed sheet prepared under optimum conditions released bFGF in a sustained manner, maintaining the bFGF concentration in the culture medium of human induced pluripotent stem cells (iPSCs) at ≥10 ng mL(−1) even without medium change for as long as 3 d. The bFGF released from the sheet retained its biological activity to support colony formation of iPSCs while preserving their pluripotency. This type of bFGF-releasing sheet can be used as a new form of bFGF supplement for the culture media of stem cells and would make a significant contribution to stem cell-based research and development.