A potential cell affinity sorbent: Fibronectin carrying poly(EGDMA/HEMA) microbeads

Both non-swellable and swellable poly(EGDMA/HEMA) microbeads were produced by suspension copolymerization. These microbeads were modified by immobiliz ation of a spacer-arm (hexamethylene diamine, HMDA) and fibronectin. The op timal values for modifications were as follows: the sodium periodate concen tration 1.0 mg ml(-1); the HMDA concentration 4 mg ml(-1); and the glutaral dehyde concentration 0.070 mu g ml(-1). Adsorption of fibronectin onto the plain and periodate-oxidized poly(EGDMA/HEMA) microbeads were very similar, and were 0.025-0.035 mg fibronectin per g polymer, respectively. Fibronect in immobilization on poly(EGDMA/HEMA) microbeads were studied at different temperature, time and pH using single protein solution containing different amount of proteins. The optimal values for immobilizations were as follows : the initial fibronectin concentration 0.1 mg mi; temperature + 25 degrees C; pH 7; the immobilization time 120 min. Both fibroblastic 3T3 and epithe lial MDBK cells were attached to these unmodified and modified microbeads. The attachments of both 3T3 and MDBK cells, especially to the fibronectin-i mmobilized swellable microbeads, were very high. Almost 96% of the 3T3 cell s available in the cell culture medium did attach to these microbeads (2345 +/- 98 cells per mg of polymer).