Surface Engineering for Mechanical Enhancement of Cell Sheet by Nano-Coatings

Cell sheet technology is becoming increasingly popular in tissue engineering and regenerative medicine, due to integrity into versatile organ and manageable cell and tissue type from the bank, and no needs of large volume organ for transplantation. Cell sheets have still a room to resolve the mechanical resistance under load-bearing occasion, easy translocation into organ, and prompt shape modulation for regular application in vivo. Herein, a layer-by-layer (LbL) assembly of nanometer scaled film coating method was introduced to inter-planar cell sheet for multilayered cell sheet (M1) and a single cell before sheet formation (M2). Nano-films with collagen and alginate increased mechanical property of cell sheets without altering cell functions, viability, and proliferation. The moduli of triple layered cell sheet (M1) and (M2) were critically enhanced to 109% and 104%, compared to uncoated cell sheet (CON) with mono-layer, while modulus of CON with triple-layers were increased to 43%. LbL assembly to cell sheets offers increased modulus allowing cell sheet engineering to become a potential strategy under load-bearing environment.