A bioassay of thyrotrophin by photografted mammalian cells onto polymeric supports

Viable and functionally responsive human thyroid follicular cells, suspended in a commercial polyester acrylate diluted with tripropyleneglycol diacrylate, photoinitiated, and photocatalyzed with a proprietary photocatalytic system based on a synergic mixture of vanadium (V) t-butoxide and i-propoxide, have been immobilized as monolayers onto polystyrene plates. Bioassay of thyrotrophin in immobilized cell cultures yielded, by log-log plot of the dose–response curve, a slope (0.92 ± 0.02) in close agreement with that (0.91) reported for cells immobilized by physical adsorption. The decisive role of photocatalyst in the photografting procedure has also been shown experimentally. A mechanism is suggested by which cells are anchored, rapidly and with stable chemical bonds, onto one of the two acrylate functions of the monomer–prepolymer mixture, the other one being simultaneously responsible for photochemical grafting onto the support. © 1993 John Wiley & Sons, Inc.