Attachment of 3T3 and MDBK Cells onto PHEMA-Based Microbeads and their Biologically Modified Forms

Polyhydroxyethylmethacrylate (PHEMA) microbeads in a size range of 150-250 μm were prepared by suspension polymerization in an aqueous phase containing magnesium oxide. Hydroxyl groups were oxidized with NaIO₄ and cell adhesive proteins, namely collagen and fibronectin, were immobilized using glutaraldehyde. A spacer-arm, hexamethylene diamine, was used in some cases. Higher amounts of collagen were immobilized, than in fibronectin. The 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. The attachments of both cells, even onto plain microbeads, were significant. Introducing both fibronectin and collagen onto the microbeads caused significant increases in the cell attachment. More cells attached to the microbeads carrying fibronectin covalently attached onto the microbeads through the spacer-arm molecules. Fibronectin was better than collagen for high attachment values. The mathematical model proposed successfully simulated attachment kinetics.