Seamless signal transduction from live cells to an NO sensor via a cell-adhesive sensing matrix.

A smart live-cell assay was developed as a cellular biosensing system. This system is based on novel tactics: the direct assembly of human cultured cells onto a cell-adhesive sensing matrix. This novel design provides considerable advantages, among them the possibility of capturing molecular signals immediately after they are secreted from living cells. The design also helps preserve all cellular characteristics intact. In this study, a cell-adhesive NO sensing matrix, acting as both an NO-permeable membrane and a cell-adhesive scaffold, was designed using functional polymers and a short peptide sequence derived from extracellular matrix (ECM) proteins. Using the cell-adhesive NO sensing matrix, we constructed a cellular biosensing system based on in situ monitoring of NO released from a human umbilical vein endothelial cell (HUVEC) layer. HUVECs were employed as an organ-functional model of a blood vessel in view of screening vasodilatory substances for clinical purposes. In our novel system, the electrochemical NO sensor is adjacent to the NO-producing cells, which allows the sensing device to achieve superior sensitivity and precise response to a very low number of NO molecules. Our design enables the fixing of the exact distance between the organ-functional model and the chemical sensor without cumbersome manipulations. Consequently, this cellular biosensing system may be readily applicable to high-throughput analysis in the field of drug screening.