"Illustrative of polymers suitable for use in the present invention are polyolefins, such as polystyrene, polypropylene, polyethylene, polytetrafluorethylene, polyvinylidene difluoride, and polyvinylchloride; polyethylenimine or derivatives thereof; polyethers, such as polyethyleneglycol; polyesters, such as poly(lactide/glycolide); polyamides, such as nylon; polyurethanes; colestipol and derivativ" . . . .