The effect of a support composed of polymers based on poly-N-isopropyl acrylamide and poly-t-butyl acrylamide and collagen on human fibroblasts was studied. As the temperature was decreased to 4 degrees C, the polymeric support is converted to a diluted state and cells spontaneously detached from it. The presence of collagen in the support prevented the detachment of cells and increased cell growth. It was shown by microcalorimetry, that in a copolymer-collagen mixture, a microstratification takes place.