Electrochemical Imaging of Cell Activity in Hydrogels Embedded in Grid-shaped Polycaprolactone Scaffolds Using a Large-scale Integration-based Amperometric Device.

Tissue engineering requires analytical methods to monitor cell activity in hydrogels. Here, we present a method for the electrochemical imaging of cell activity in hydrogels embedded in printed polycaprolactone (PCL) scaffolds. Because a structure made of only hydrogel is fragile, PCL frameworks are used as a support material. A grid-shaped PCL was fabricated using an excluder printer. Photocured hydrogels containing cells were set at each grid hole, and cell activity was monitored using a large-scale integration-based amperometric device. The electrochemical device contains 400 microelectrodes for biomolecule detection, such as dissolved oxygen and enzymatic products. As proof of the concept, alkaline phosphatase and respiration activities of embryonic stem cells in the hydrogels were electrochemically monitored. The results indicate that the electrochemical imaging is useful for evaluating cells in printed scaffolds.