title: PDMS-based polyurethanes with MPEG grafts: synthesis, characterization and platelet adhesion study.
abstract: Polyurethane (PU), based on poly(dimethyl siloxane) (PDMS) as a soft segment, with monomethoxy poly(ethylene glycol) (MPEG) grafted onto it, was synthesized as a new polymeric biomaterial for coating PDMS-based biomedical devices. Two different chain extenders, ethylene glycol (EG) and diethyl bis(hydroxymethyl) malonate (DBM), were used for the synthesis of PDMS-based PUs and then MPEG was grafted onto them by allophanate and esterification reactions, respectively. Their molecular structures were confirmed qualitatively and quantitatively using FT-IR and 1H-NMR measurements. PDMS-based PU was more hydrophobic than Pellethane, which is a commercial biomedical-grade poly(ether urethane), due to the PDMS-rich phase at the polymeric surface. However, the incorporation of MPEG in PDMS-based PU induced an increase in hydrophilicity. Analyses of their morphology using dynamic mechanical analysis and differential scanning calorimetry showed that the degree of phase separation increased with the content of hard segments. It also showed that MPEG is compatible with a hard segment consisting of 4,4'-diphenylmethane diisocyanate (MDI) and DBM, while being incompatible with one consisting of MDI and EG. Platelet adhesions with PDMS-based PUs were significantly reduced when compared with Pellethane. It was also observed from a platelet adhesion experiment that the incorportion of MPEG further reduced platelet adhesion. PDMS-based PUs with MPEG grafts, which have few hard segments and a distinct PEG phase, exhibited the least platelet adhesion among the polymer samples tested.
authors.affiliation: Center for Biomaterials and Biotechnology, Department of Materials Science and Engineering, Kwangju Institute of Science and Technology, South Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Park
authors.forename: K D
authors.initials: KD
authors.lastname: Park
authors.forename: Y H
authors.initials: YH
authors.lastname: Bae
mesh_terms: D001672:Biocompatible Materials / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008970:Molecular Weight; D010973:Platelet Adhesiveness / Q000187:drug effects; D011092:Polyethylene Glycols / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry; D011140:Polyurethanes / Q000009:adverse effects / Q000138:chemical synthesis / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D011140:Polyurethanes; C093451:polyurethane polydimethylsiloxane; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol