Semi-interpenetrating polymer networks composed of biocompatible phospholipid polymer and segmented polyurethane

2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers, which have excelle nt biocompatibility, have been receiving increasing attention in biomedical and bioengineering fields; however, the mechanical strength of the hydrate d MPC polymers is not sufficient for use in these fields as a bulk material . Therefore, we hypothesized that a novel material might be realized by rei nforcing the MPC polymer network with segmented polyurethane (SPU). Semi-in terpenetrating polymer networks (IPNs) composed of crosslinked MPC polymer and SPU were prepared. The mechanical properties of the IPN membrane were s ignificantly improved compared with those of the MPC polymer membrane. Thre e-dimensional polymer networks of the MPC polymer in the IPNs were observed after solvent extraction of SPU. An X-ray photoelectron spectrum analysis revealed that the MPC units were exposed on the IPN surface. When the IPN w as alternately soaked in water and ethanol, the swelling ratio was found to be completely reversible and no disintegration of the network structure wa s observed. The permeation coefficient of 1,4-di(2-hydroxyethoxy)benzene th rough the IPN membrane was 1.11 x 10(-7) cm(-2)s(-1). The amount of adsorbe d protein and the number of adherent platelets on the IPN membrane were eff ectively reduced compared with those on SPU. We concluded that IPNs compose d of the MPC polymer and SPU are a new bulk biomaterial, which possesses bo th blood compatibility and good mechanical properties. (C) 2000 John Wiley & Sons, Inc.