Cell growth on poly(EGDMA/HEMA) based microbeads

Poly(EGDMA/HEMA) copolymeric microbeads were prepared by suspension polymerization. A comonomer, i.e., HEMA, was included in the formula in order to provide functional hydroxyl groups on the microbead surfaces. Toluene was used in the polymerization formulations to introduce porosity into the matrix. Hydroxyl groups were first oxidized with NaIO4, and then two biological molecules, namely collagen and fibronectin were immobilized by using glutaraldehyde. A spacer-arm, i.e., hexamethylene diamine, was also used in some cases. More protein molecules were immobilized onto more swellable microbeads using spacer-arm. Higher amounts of collagen were immobilized, more than fibronectin immobilization. Growth of two cell lines, 3T3 and MDBK, on these microbeads with a wide variety of surface properties was studied in vitro culture media. Growths of both cells even onto the plain microbeads were significant. More cell proliferation occurred with the more swellable microbeads. More cells proliferated on the microbeads carrying fibronectin covalently attached onto the microbeads through spacer-arm molecules. Fibronectin was better than collagen for promoting high proliferation. The mathematical model proposed successfully simulated the growth kinetics.