Attachment of 3T3 and MDBK cells onto poly(EGDMA/HEMA) based microbeads and their biologically modified forms

Poly(EGDMA/HEMA) based microbeads were prepared by suspension polymerization. A comonomer, i.e., 2-hydroxyethylmethacrylate (HEMA) was included in the recipe in order to have 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. Attachment of two cell lines (i.e., 3T3 and MDBK cell lines) on these microbeads with a wide variety of surface properties was studied in vitro culture media. Attachments of both cells even onto the plain microbeads were significant. More cells did attach to more swellable microbeads. Introducing both fibronectin and collagen onto the microbeads caused significant increase in the cell attachment. More cells attached to the microbeads carrying fibronectin covalently attached onto the microbeads through the spacer-arm molecules. Fibronectine was better than collagen for high attachment values. The mathematical model proposed successfully simulated attachment kinetics.