Assessment of cell detachment and growth potential of human keratinocyte based on observed changes in individual cell area during trypsinization

In the detachment process of human keratinocyte cells with trypsin, morphological changes of individual cells were observed to estimate the cellular property. The kinetic parameters, alpha(i)/k and delta(i)/k, were proposed as indices concerning the adhesive force of each cell and density of adhesive strength, respectively, and these parameters were determined from the time profiles of cell shrinkage during the trypsinization. The value of alpha(i)/k decreased with detachment process time, t(T), and ultimately entered into a region of alpha(i)/k = 0-4.0 mm s at t(T) = 720 s. The profile of cell detachment could be described in fair agreement with experimental data, by considering that the cells with less than alpha(i)/k = 4.0 mm s were detached ones from the surface. In subsequent cultures of the cells detached during trypsinization, it was found that the cells included in a fraction with small delta(i)/k values exhibited the deteriorated growth potential. It was thus demonstrated that the proposed parameters could be useful measures to predict the adhesive and proliferative abilities of the anchorage-dependent cells. (C) 2003 Elsevier B.V. All rights reserved.