COLLAGEN AND FIBRONECTIN CARRYING PHEMA MICROBEADS AS CELL AFFINITY SORBENTS

PHEMA microbeads, produced by suspension polymerization, were modified by the immobilization of a spacer (hexamethylene diamine, HMDA), and two proteins, collagen or fibronectin. Adsorption of collagen and fibr onectin onto the plain and periodate oxidized PHEMA microbeads were si milar; 0.05-0.1 mg of collagen and 0.04-0.05 mg of fibronectin per g o f polymer, respectively. Collagen and fibronectin immobilization on PH EMA microbeads were studied at different temperatures, time and pH. Th e optimal values for immobilization were 0.1 mg/mL for fibronectin; an d 0.25 mg/mL for collagen at 25 degrees C for fibronectin and 4 degree s C for collagen; pH 7 in 120 min. Both fibroblastic 3T3 and epithelia l MDBK cells were attached to unmodified and modified microbeads. The attachments of both 3T3 and MDBK cells, to the fibronectin and collage n immobilized microbeads were more than 2000 cells per mg of polymer.