Impact of starch content on protein adsorption characteristics in amphiphilic hybrid graft copolymers

Amphiphilic hybrid graft copolymers were synthesized using a graft-to methodology and their protein adsorption profiles studied. Three different hydrophilic side chains were studied: hydroxypropylated high amylose starch, maltodextrin, and polyethylene glycol (PEG). In the high amylose starch compositions, there was a pronounced decrease in protein adsorption with increasing polysaccharide content. As the starch content in the graft copolymers increased from 10 wt% to 53 wt%, BSA protein adsorption decreased by 83% whereas fibrinogen adsorption was reduced by 40%. Comparisons between the starch-containing hybrid polymers and their respective hydrophobic urethane-linked polyesters were also made. Hybrid 53, containing 53 wt% starch, showed a 85% reduction in BSA adsorption and 51% reduction in fibrinogen relative to their urethane-linked polyester backbone controls. Grafting branched high amylopectin-derived maltodextrin to the synthetic polymer backbones also conferred modest protein resistance to the hydrophobic backbone polymer. Lastly, it was found that a high amylose graft structure provided comparable, if not slightly more effective, protein resistance compared to a similarly constructed PEG-containing amphiphilic copolymer.