Synthesis and electropolymerization of phosphorylcholine-containing pyrroles and their hemocompatible properties

A series of N-substituted pyrroles having phosphorylcholine with different methylene chain lengths between pyrrole group and phosphorylcholine group were synthesized and their electropolymerizations were performed in aqueous solution. The methylene chains were trimethylene (n = 3), pentamethylene (n = 5), nonamethylene (n = 9), and undecamethylene (n = 11), for 3-(1-pyrrolyl)propyl-2-(trimethylammonium)ethyl phosphate (5a), 5-(1-pyrrolyl)pentyl-2-(trimethylammonium)ethyl phosphate (5b), 9-(1-pyrrolyl)nonyl-2-(trimethylammonium)ethyl phosphate (5c), and 11-(1-pyrrolyl)undecyl-2-(trimethylammonium)ethyl phosphate (5d), respectively. Although electropolymerized films were produced from all pyrrole derivatives, thick and black polymer films were prepared from 5a, 5b and 5c. The pyrrole derivative with long methylene-chain 5d provided only colorless or slightly blackish thin film. Hemocompatibilities of the polymers from 5a, 5b and 5c were evaluated by platelet rich plasma (PRP) contacting studies and scanning electron microscopy (SEM) observations. The results indicated that these polymers have excellent hemocompatibility.