Attachment kinetics of Vero cells onto CT-3 microcarriers

The effects of cell seeding density, microcarrier concentration, agitation speed and age of seeding cells on the rate of cell attachment to the surfac e of CT-3 microcarriers were investigated. It was shown that the attachment followed first-order kinetics. When either the cell seeding density or the microcarrier concentration was increased, the kinetic constant increased d ue to an increase in the probability of collision between cells and microca rriers. However, at higher microcarrier concentrations, the increase in the kinetic constant with increasing microcarrier concentration was not signif icant. Cell attachment was decelerated upon increasing the agitation speed because of the shorter cell-microcarrier contact time. In addition, it was also demonstrated that cell attachment occurred more efficiently when seedi ng cells from the middle or early exponential growth phase were used. The p rocess of cell attachment onto CT-3 microcarriers was investigated, and our results showed that the attachment stage was the rate-limiting step. These results will facilitate the optimization of the Vero cell culture process.