Detachment of human mesenchymal stem cells from a gold substrate using electric current

Abstract

The control of cell/substrate interactions is important in tissue engineering. In particular, detaching cells from a substrate without causing damage is critical when cell sheet recovering. Adherent cells in tissue culture adhere to a substrate via the extracellular matrix (ECM), and can be detached by denaturation of the ECM. In this work, collagen converted into gelatin by flowing an electric current through the Au substrate. Human mesenchymal stem cells were successfully detached by the electric current, while retaining their viability. In addition, the binding characteristics between the adhesion motif of the ECM and the metal ion-dependent adhesion site (MIDAS) of integrin as well as between the adhesion motif and the Au substrate were investigated using first principle calculations to understand the origins of differences in binding between collagen and gelatin. The binding energy of collagen with the MIDAS was more negative than that with the Au substrate while that of gelatin with the MIDAS was less negative than that with the Au substrate. These calculation results support the experimental finding that the electric current induced denaturation of collagen led to cell detachment. The origins of different binding characteristics were discussed from the perspective of binding states with the oxygen atoms of the carboxyl groups. The cell detachment technique developed in the present work has a potential to be applied to cell sheets recovery without enzymes.