Modulation of marrow stromal cell function using poly(D,L-lactic acid)-block-poly(ethylene glycol)-monomethyl ether surfaces.

The adhesion of marrow stromal osteoblasts and the adsorption of fetal bovine serum (FBS) proteins to end-capped poly(D,L-lactic acid) 50:50 (PLA50) of molecular weight 17,000 (PLA5017), non-end-capped PLA50 of molecular weight 11,000 (PLA5011h), and a diblock copolymer made of poly(ethylene glycol)-monomethyl ether of molecular weight 5,000 and PLA50 of molecular weight 20,000 (Me. PEG5-PLA20) were investigated. Cell attachment and proliferation on both PLA50 polymers were equally good. The block copolymer did not allow the proliferation of cells. However, the attached cells were highly differentiated and metabolically active in contrast to the cells on PLA50. Moreover, surface analysis studies using electron spectroscopy revealed that FBS proteins adsorbed well from aqueous solutions to the PLA50 surfaces while they adsorbed substantially less to the block copolymer. These results suggest that Me.PEG-PLA block copolymers may be used to regulate protein adsorption and, therefore, cell adhesion by varying the block composition of the copolymer.