The respiratory activity of collagen-embedded living cells was imaged by scanning electrochemical microscopy (SECM) with the objective to study anticancer drug sensitivity. Two kinds of cancer cells, the human erythroleukemia cell line (K562) and its adriamycin-resistant subline (K562/ADM), were immobilized at the array of microholes micromachined on a silicon wafer for comparative characterization of their sensitivity to the anticancer drug, ADM. The results obtained by the SECM method showed correspondence to a conventional colorimetric assay (SDI assay). Furthermore, since the SECM assay is based on the noninvasive measurement of the respiration activity, continuous monitoring of a dose response was possible.

No abstract

The microcontact printing (µCP) is a well-established method to pattern a material of interest using an elastomeric stamp. We have developed two techniques which assist the µCP-based cell-patterning for the controlled growth guidance of cultured neuronal cells on substrates. (i) Contact-transfer of extracellular matrix (ECM) protein on a microelectrode array substrate was achieved by spatially designing the microstamp to allow printing proteins even on the surface having uneven structures, and the differentiated PC12 cells showed selective adhesion and growth in the pre-determined locations on the electrode array. (ii) Cell alignment onto the pre-patterned ECM protein was also succeeded by using the microstructured silicon wafer having a band array of microholes, and the placed PC12 cells extended their axons along the protein pattern. These researches were carried out with the objective to developing a cell-based device based on a cellular network.