Enzymatically crosslinked carboxymethylcellulose-tyramine conjugate hydrogel: cellular adhesiveness and feasibility for cell sheet technology.

An aqueous solution of carboxylmethylcellulose with phenolic hydroxyl groups (CMC-Ph) is gellable within 1 min via a peroxidase-catalyzed oxidative reaction under mild conditions suitable for mammalian cells. In this research, we evaluated cellular adhesion and proliferation on the resultant hydrogel, and the feasibility of the hydrogel as a substrate for cell sheet technology. Within 4 h of seeding, 76.9% of L929 fibroblast cells adhered to the gel and showed similar morphology of spreading to that on cell culture dish. Subsequently, the adherent cells proliferated on the gel and formed a confluent monolayer after 168 h of culture. From the confluent monolayer we could harvest a cell sheet after about 5 min of digestion of the gel using cellulase dissolved in medium at 5 U ml(-1). The cells in the cell sheet showed well-preserved morphology similar to that shown before they were detached from the gel. In addition, the harvested cell sheet readhered and proliferated after being transferred to another culture dish. These results demonstrate that CMC-Ph gel is a good candidate material for obtaining cell sheets.