Modulation of cellular growth in vitro by growth factor inactivation with selenium covalently attached to an inert cellulose matrix

We have shown that selenium attached to a matrix is very effective in the production of superoxide radicals. Thus, experiments were carried out to determine whether selenium attached to a covalent cellulose matrix (Se-CM) could inactivate growth factors resulting in the blockage of cellular growth. Selenium as selenocystamine was covalently attached to a surgical sponge which was placed in a 24 well insert which suspended it over cells growing in culture. The cells tested were mouse lens epithelial cells, rabbit corneal epithelial cells and rabbit tenons fibroblasts. We found that the Se-CM pads suspended above the cells could block cellular growth both in the presence of 10% fetal calf serum and purified basic fibroblast growth factor (bFGF). In order to show that the blockage of growth was not due to a direct effect of the superoxide radical on the cells we suspended the Se-CM pad in a solution of FCS. After re moval of the pad we then allowed the solution to set for 10 hours and then used this solution to treat the cells. This solution was unable to stimulate cellular growth. However, if after removal of the pad, growth factor was added back to the solution it was capable of stimulation of cellular growth. Thus, selenium appears to modulate cellular growth by inactivation of growth factors.