Segmented Polyurethane Film Research Articles

Strain-induced molecular aggregation states around a crack tip in a segmented polyurethane film under uniaxial stretching

The development of molecular aggregation structures during stretching deformation and local structure mapping around a crack tip of a segmented polyurethane elastomer film were investigated by in situ simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) and by micro-beam WAXD, respectively. Both the hard segment (HS) domain orientation and the strain-induced crystallization of poly(ε-caprolactone) chains were tracked by the WAXD pattern due to the high crystallinity of the symmetric non-bulky aliphatic HS structure. Strain-induced crystallization occurred locally at the vicinity of the crack tip, and the crystallinity immediately decayed in the exterior, whereas the HS domain orientation was observed throughout the stretched film. The mechanisms underlying crack arrest and the mechanical strength of polyurethane elastomer films are associated with the local strain-induced crystallization at the crack tip, the mechanical stability of the HS domains, and the avoidance of local stress concentration through the HS domain orientation.

Transparent and flexible films of new segmented polyurethane nanocomposites incorporated by NH2-functionalized TiO2 nanoparticles

Abstract In this work, TiO 2 nanoparticles are surface modified by NH 2 -terminated organic moieties arised from 4,4′-methylene diphenyl diisocyanate (MDI). These nanoparticles are incorporated into ether-based segmented polyurethane (SPU) matrix. MDI is utilized as monomer together with poly(tetramethylene oxide) (PTMO) comonomer for preparing the final polymer as well. The NH 2 -functionalized TiO 2 nanoparticles are covalently linked to the NCO terminals of the resulting SPU macromolecules during film preparation stage. Therefore, in addition to butylene glycol, these surface modified nanoparticles with enhanced organophilicity could play the role of the second chain extender of NCO-capped SPU macromolecules through formation of urea linkages. Optical and thermal behaviors of the transparent and flexible film (SPU/TiO 2 –MDI) is compared with those of unmodified TiO 2 (SPU/TiO 2 ) and TiO 2 -unloaded SPU films. Though the particle loading is only 5 wt.%, incorporation of TiO 2 and TiO 2 –MDI nanoparticles into the SPU polymer enhances significantly the light absorption in UV region at 300–400 nm. SEM images of the prepared films clearly show a considerable decrease in particle aggregation for TiO 2 –MDI into SPU matrix compared to that of unmodified TiO 2 . TG analyses indicate a one-step decomposition pattern with onset temperatures of about 360 and 380 °C for neat SPU and SPU/TiO 2 –MDI, respectively. Moreover, DTA thermograms of both nanocomposites show obviously two exothermic phase transitions in the thermal range of 330–440 °C.

Effects of Dyeing Temperature and Molecular Structure on the Dye Affinity of Polyurethane Films containing Polyethylene Glycol Segments

The dyeing behavior of segmented polyurethane containing copolymerized polyethylene glycol soft segments was investigated. Four types of segmented polyurethane were prepared by controlling the aggregation of the hard segments and the mobility of polyethylene glycol in the soft segments. Dyeing rate curves and sorption isotherms were obtained for direct dyes at various temperatures along with the swelling ratios of the different segmented polyurethane samples. The sorption of CI Direct Red 28 by these samples is shown to decrease with increasing dyeing temperature, with the swelling ratio of the segmented polyurethane film also decreasing. Changes in the tensile strength of the films before and after dyeing with CI Direct Red 28 are shown to be related to the degree of aggregation of the hard segments, as well as to the amount of dye used.

Hydrolytic degradation of segmented polyurethane copolymers for biomedical applications

The hydrolytic degradation of a series of segmented polyurethane (SPU) copolymers with potential for biomedical use has been investigated. A series of polyurethane copolymers were prepared from 1,6 - diisocyanatohexane (HDI), polycaprolactone diol (PCL), 2,2 - bis(hydroxymethyl) propionic acid (DMPA) and ethylene glycol (EG). The synthesized SPUs have a low soft segment glass transition temperature, a melting temperature around 50 °C, and a significant tailorable hardness for tissue engineering applications. Tensile testing of SPU films at 37 °C in phosphate buffered saline (PBS) indicated that the Young's modulus and elongation of the polyurethane copolymers could be tailored by altering the soft segment block length. All polyurethanes demonstrated hydrolytic degradability, which was measured in PBS solution at 37 °C, and the rate of degradation of the polyurethanes could be somewhat tailored by controlling the soft segment length.

Evaluation of self‐expandable, FK506‐coated, covered stents in canine animal model

This study aimed to evaluate whether drug coating of the recently developed covered SENDAI stents--self-expandable stents covered with segmented polyurethane (SPU) films--reduces neointimal thickening in animal model. FK506, which is one of the most effective immunosuppressants, was used. Bare stents; non-coated, covered stents; and FK506-coated, covered stents were placed bilaterally in the external iliac arteries of beagle dogs. After 1-month observation period, angiography did not show significant stent-induced stenosis. Histological evaluation revealed a completely endothelialized intravascular lumen and the absence of thrombus formation. The area of the intimal thickening induced by the FK506-coated stents was significantly smaller than that induced by the non-coated stents, whereas it was larger in the case of both the covered stents than that in the case of the bare stent. In conclusion, FK506 treatment of the self-expandable, covered stents was confirmed to effectively inhibit intimal thickening, although the SPU film used for covering functioned as a drug carrier in addition to a scaffold for intimal formation.

セグメントポリウレタンにおけるソフトセグメント成分の変化に伴う染色性の変化

The aim of this study is to clarify the dyeing behavior with acid dyes in the segmented polyurethanes with soft segments composed of various ratios of PTMG and PEG components by measuring the dye uptake. Experiments revealed that the higher ratio of PEG component resulted in increasing the hydrophilic property and decreasing the aggregate structure in the segmented polyurethanes. Aqueous dyeing solution, consequently, seemed to adsorb positively into the intra-molecules of polyurethanes.Considering the stress-strain relations and water-swelling characteristics of polyurethane films, the dye affinities of the films before and after dyeing were evaluated. After dyeing, the segmented polyurethane films seemed to losing hydrogen-bonding ability resulting in making the aggregate structure small. It was suggested that the dyestuff molecules were adsorbed in the hard segments of the polymers with some form of bonding.Furthermore, it was observed that the dye adsorption for CI Acid Red 114 was higher than that for CI Acid Red 37 among two kinds of acid dyes applied in this study. It was suggested as follows: (1) CI Acid Red 114 having bulky molecular structure against CI Acid Red 37, ca. 1.6 times in molecular weight, contributed to adsorb into the segmented polyurethanes with van der Waals forces. (2) CI Acid Red 114 molecule modified with formic acid in dyeing bath changing to insoluble form for water adsorbed easily onto the hydrophobic group of the segmented polyurethanes.

Structural characterization and mass transfer properties of dense segmented polyurethane membrane: Influence of hard segment and soft segment crystal melting temperature

AbstractAn attempt has been taken to investigate the microstructure and mass transfer properties of polycaprolactone diol (Mn = 2000 g mol–1, PCL 2000)‐based dense segmented polyurethane (SPU) membrane as a function of hard segment (HS) content. Structure of SPUs were investigated by Fourier transform infrared analysis, wide angle X‐ray diffraction, differential scanning calorimetry, dynamic mechanical thermal analysis, and scanning electron microscopy (SEM). On the other hand, mass transfer properties were measured by equilibrium sorption, dynamic sorption, and water vapor permeability measurements. From the experimental results, it was observed that with the increasing HS content in SPU the percentage crystallinity decreases, whereas the glassy state storage modulus increases. α transition temperature of polyurethane copolymers also increases with increasing HS content. SEM micrograph shows the dense surface structure of SPU films. Mass transfer rate of dense polyurethane membranes decreases with increasing HS content. In contrast, hydrophilic segment and soft segment crystal melting could enhance the mass transfer properties. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers

Structure and Drug Release in a Crosslinked Poly(Ethylene Oxide) Hydrogel

Hydrogels are a continuously expanding class of pharmaceutical polymers designed for sustained or controlled drug release. The structure and intermolecular interactions in such systems define their macroscopic properties. The aim of this study was to investigate the mechanism of swelling, drug impregnation, and drug release from poly(ethylene oxide) (PEO) gel crosslinked by urethane bonds. A combination of SAXS/WAXS/SANS techniques enabled us to determine the phase transition between lamellar and extended gel network, and to apply different descriptions of crystallinity, based on lamellar and crystal lattice structures. It is shown that even low (1-7% w/w) loading of model drugs acetaminophen and caffeine, produced significant disorder in the polymer matrix. This effect was particularly pronounced for acetaminophen due to its specific ability to form complexes with PEO. The drug-release profiles were analyzed using a general cubic equation, proposed for this work, which allowed us to determine the gel hydration velocity. The results indicate that the release profiles correlate inversely with the polymer crystallinity.

Development of Biocompatible Interpenetrating Polymer Networks Containing a Sulfobetaine-Based Polymer and a Segmented Polyurethane for Protein Resistance

Interpenetrating polymer networks (IPNs) were prepared by the modification of a segmented polyurethane (SPU) with a cross-linked sulfobetaine methacrylate (SBMA) polymer. The IPN films that were prepared can effectively resist nonspecific protein adsorption when the distribution of SBMA units within the SPU film is well controlled, and they retain high mechanical strengths inherent from the base SPU films. Furthermore, the zwitterionic and biomimetic nature of sulfobetaine and the ease of SBMA preparation make SBMA-based materials very attractive for a wide range of applications. It is challenging to control the diffusion of highly polar SBMA into the hydrophobic network of SPU. In this study, various parameters governing the formation of IPNs containing SBMA were studied. The chemical composition depth profile of the IPN films was determined by confocal Raman microscopy. The morphology and thickness of these IPN films were examined by atomic force microscopy and scanning electron microscopy. The amount of adsorbed proteins on the IPN films was determined by an enzyme-linked immunosorbent assay. Results show that the amount of adsorbed proteins on the IPN films depends on the incubation conditions, including solvent polarity, incubation time, SBMA monomer ratio, and incubation concentration. It appears that the IPN films prepared in a mixed solvent of higher polarity with long incubation time lead to very low protein adsorption. This study not only introduces a new IPN system containing SBMA, but also provides a fundamental understanding of various parameters governing the formation of IPNs.

Stress response of adherent cells on a polymer blend surface composed of a segmented polyurethane and MPC copolymers

To better understand the effect of 2-methacryloyloxyethyl phosphorylcholine (MPC) copolymer in improving the biocompatibility of segmented polyurethane (SPU), the expression of heat shock protein (HSP) mRNA in HeLa S3 cells adhered on SPU blended with MPC copolymers was measured. Conventionally, MPC copolymers (PMEH) were synthesized by changing the feed ratios of MPC and 2-ethylhexyl methacrylate. X-ray photoelectron spectroscopic analysis of the SPU/PMEH film indicated that the surface concentration of MPC units on the SPU/PMEH film increased with an increase in PMEH composition. HeLa S3 cells were cultured on SPU/PMEH films. The number of adherent cells on the SPU/PMEH films decreased with an increase in the concentration of PMEH. When the PMEH composition was greater than 0.5 wt %, cell adhesion and proliferation decreased markedly. Expressions of HSP27 and HSP47 mRNA were detected using the reverse transcription-polymerase chain reaction (RT-PCR). After incubation for 24 h, both the HSP mRNA expressions in the HeLa S3 cells showed no significant differences among all samples. In HeLa S3 cells that adhered to the SPU film for 48 h, the expressions of HSP27 and HSP47 mRNA increased significantly when compared with those incubated for 24 h. In contrast, the two kinds of mRNA expressions decreased in the HeLa S3 cells that adhered to the SPU/PMEH films for 48 h. From these results, we concluded that PMEH was quite important in suppressing the stress response of adherent HeLa S3 cells. Therefore, SPU/PMEH blend polymers are useful as implantable biomedical materials.

ポリウレタンフィルムの構造と透湿性

Segmented polyurethane is a block copolymer which consists of hard and soft segments. In this study, moisture permeable segmented polyurethane films with different content of polytetramethyleneglycol (PTMG) and polyethyleneglycol (PEG) as soft segment were used. Three parameters of C1, C2 and higher order term Δh calculated by Mooney-Rivlin plots in the stress-strain relationship were measured. It was clarified that these mechanical parameters had relation with structure of films. Higher order term Δh and hydrogen bond concentration of urethane group by FT-IR measurement decreased with increasing PEG content in soft segment. That is to say, aggregate structure of hard segment decreased with increasing PEG content. Low PEG content samples showed transverse orientation in relation to aggregate structure of hard segment at initial state of elongation process. Transverse orientation has correlation with magnitude of aggregate structure. In the case of soft segment, degree of molecular restraint evaluated by dynamic mechanical analysis decreased with increasing PEG content. Aggregate structure grows through hydrogen bond of urethane group in hard segment. Also, it was clarified that aggregate structure was affected by soft segment and its outgrowth was inhibited.

Nano-scale surface modification of a segmented polyurethane with a phospholipid polymer

Nano-scale modification of a segmented polyurethane (SPU) with cross-linked 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer was performed to obtain a biocompatible elastomer. To control the domain size and the depth of the modified layer, various compositions of monomers, including MPC, 2-ethylhexyl methacrylate (EHMA), and glycerol 1,3-diglycerolate diacrylate, were examined. SPU film was immersed in the monomer solution and visible light irradiation was applied to initiate polymerization to the SPU film that was held by mica to condense MPC units at the surface. The surfaces of the obtained film were analyzed by X-ray photoelectron spectroscopy and water contact angle measurement. The surface density of MPC units changed with the monomer concentration, and the density was the highest when the ratio between MPC and EHMA was 7:3. In modified SPU films, 6- to 25-nm MPC unit-enriched domains were observed and the density of these domains gradually decreased with depth. The sizes of the domains depended on the MPC composition in the monomer solution. The mechanical properties of the modified films as evaluated by tensile strength measurement under wet conditions were not significantly different from those of SPU. With increase in the existence of MPC unit-enriched domains on the MEG film surface, platelet adhesion and activation were remarkably reduced compared to the SPU film. This nano-scale surface modification may be a useful technique for applying elastic polymer biomaterials.

Platelet adhesive resistance of segmented polyurethane film surface-grafted with vinyl benzyl sulfo monomer of ammonium zwitterions

Platelet from human plasma adhered on the segmented poly(ether urethane) (SPEU) film grafted with N, N-dimethyl- N-( p-vinylbenyl)- N-(3-sulfopropyl) ammonium (DMVSA) was studied. SPEU films were hydroxylated by potassium peroxosulfate (KPS) and then grafted with DMVSA using ceric ammonium nitrate (CAN) as initiator. The mixing time of hydroxylated SPEU/CAN and the monomer concentration effect on graft polymerization yield were determined by ATR-FTIR. Surface analysis of the grafted films by ATR-FTIR and ESCA confirmed that DMVSA was successfully grafted onto the SPEU film surface. The grafted film possessed a relatively hydrophilic surface, as revealed by water contact angle measurement. The improved blood compatibility of the grafted films was preliminarily evaluated by a platelet-rich plasma adhesion study and scanning electron microscopy, using original SPEU and hydroxylated SPEU films as the controls. The results showed that platelet attachment was decreased greatly on the segmented polyurethane films grafted with DMVSA. This kind of new biomaterials grafted with sulfo ammonium zwitterionic monomers might have potential for biomedical applications.

Fabrication of endothelial progenitor cell (EPC)-seeded intravascular stent devices and in vitro endothelialization on hybrid vascular tissue

Rapid re-endothelialization at an atherosclerotic lesion after balloon inflation or stent deployment may be essential for reducing or preventing local thrombus formation and restenosis. In order to prevent these complications via enhanced rapid re-endothelialization, we fabricated two types of endothelial progenitor cell (EPC)-seeded intravascular stent devices. One was a photocured gelatin-coated metallic stent, and the other was a microporous thin segmented polyurethane (SPU) film-covered stent on which photocured gelatin was coated. Both devices were seeded with ex vivo expanded EPCs obtained from canine peripheral blood. Seeded EPCs formed confluent monolayers onto surfaces of both photocured gelatin-coated stent struts and SPU film, and a majority of cells remained on surfaces of stents after stent expansion. The EPC-seeded stent was expanded in a tubular hybrid vascular medial tissue composed of vascular smooth muscle cells and collagen as an arterial media mimic. After 7-day culture, EPCs, which migrated from the stent struts, proliferated and endothelialized the luminal surfaces of the hybrid vascular medial tissue. This in vitro pilot study prior to in vivo experiments suggests that on-stent cell delivery of EPCs may be novel therapeutic devices for re-endothelialization or endothelium lining or paving at an atherosclerotic arterial wall, resulting in the prevention of on-stent thrombus formation and in-stent restenosis, as well as the rapid formation of normal tissue architecture.

Coaxial double-tubular compliant arterial graft prosthesis: time-dependent morphogenesis and compliance changes after implantation.

In order to reduce the compliance mismatch between the native artery and the artificial graft, we have developed a coaxial double-tubular compliant graft, using multiply micropored segmented polyurethane (SPU) thin films, which mimics the relationship between the intraluminal pressure and vessel internal diameter (P-D) of the native artery (termed "J" curve). The graft was coaxially assembled by inserting a high-compliance inner tube with a heparin-immobilized photocured gelatin coating layer into a low-compliance outer tube with a photocured hydrophilic polymer coating layer. Twenty-eight coaxial double-tubular compliant grafts were implanted into the canine common carotid arteries in an end-to-end fashion for up to 12 months. The overall patency rate was 86% (24/28), and neither rupture nor aneurysmal formation was observed. A neoarterial wall was formed via transanastomotic and transmural tissue ingrowth, resulting in neoarterial tissue formation on the luminal surface and into the intertubular space of the double-tubular graft, accompanied by mainly myofibroblasts and inflammatory cells in the early stage and endothelialization and collagen-rich extracellular matrices in the late stage of implantation. Surrounding-tissue adhesion with the outer tube was prevented by the hydrophilic polymer coating. Although the J curve of the implanted prototype model was preserved 1 month after implantation, the impaired J curves were observed because of tissue ingrowth and tissue adhesion between the outer surface of the inner tube and the surrounding tissues 3 and 6 months after implantation. At 12 months after implantation, however, the implanted coaxial double-tubular graft exhibited high compliance due to biodegradation of the SPU films.

Human endothelial progenitor cell-seeded hybrid graft: proliferative and antithrombogenic potentials in vitro and fabrication processing.

In this article, we show that human endothelial progenitor cells (EPCs) in circulating peripheral blood may be a novel cell source for a cell-incorporated engineered vascular graft. Cultures of human peripheral blood mononuclear cells collected by the density gradient technique developed highly proliferative EPC colonies, which expanded with culture time. The production rates of antiplatelet substances such as endothelial-type nitric oxide synthase and 6-keto-prostaglandin-F(1)-alpha were approximately one-third and approximately one-half of those of mature endothelial cells (ECs), respectively. On the other hand, the tissue-type plasminogen activator production rate of EPCs was almost the same as that of ECs. EPCs were seeded and cultured on a small-diameter compliant graft (inner diameter, 1.5 mm) made of microporous segmented polyurethane film coated with a photo-reactive gelatin layer, and subsequently subjected to hydrodynamic shear stress by ex vivo circulation. EPCs fully covering the graft elongated and aligned themselves with the direction of the flow, resulting in the production of an integrated EPC-engineered graft. These results indicate that EPCs, which have high proliferative potential and high antithrombogenic potential, comparable to those of ECs, are a suitable cell source for cardiovascular tissue engineering.

Fabrication of micropored elastomeric film-covered stents and acute-phase performances.

To prevent thrombus formation in the acute phase and restenosis in the subacute to chronic phase after stenting of atherosclerotic arteries, we developed a covered stent with a micropored elastomeric film, the blood-contacting surface of which was coated with a photocured gelatin layer immobilized with heparin. Segmented polyurethane (SPU) film (30 microm in wall thickness) as a cover material was multiply micropored by excimer laser-directed microprocessing (pore diameter, 30 microm; interpore distance, 125 microm). An aqueous mixed solution of benzophenone-derivatized gelatin and heparin was coated on the micropored SPU film. Upon ultraviolet light irradiation, a thin layer of a gelatin gel immobilized with heparin was formed and simultaneously fixed on the SPU film. The fully covered stents were assembled by wrapping a balloon-expandable stent with gelatin/heparin gel-layered SPU film and subsequently suturing and then gluing. To assess the validity of this covered stent in vivo, "half-covered" stents, in which half at the distal side was covered with the gel-layered SPU film, was implanted in rabbit common carotid arteries (about 3 mm in diameter). After 3 months of implantation, all the half-covered stents (n = 7) were patent. Regardless of the covered or noncovered region of the stents, the entire luminal surface of the stents was fully endothelialized and a thin neointimal tissue was formed. The potential advantages of a covered stent as designed above are discussed.

Newly Designed Compliant Hierarchic Hybrid Vascular Grafts Wrapped with a Microprocessed Elastomeric Film—I: Fabrication Procedure and Compliance Matching

The object of this study was to develop a compliant hybrid vascular graft minimally supported by an elastomeric scaffold for arterial replacement. The hybrid vascular grafts designed were composed of three layers: an inner surface lined with endothelial cells (ECs); a hybrid medial tissue composed of a collagenous gel embedded with smooth muscle cells (SMCs); and an outer layer made of a laser-processed micropored segmented polyurethane (SPU) film with the circular pore size (diameter 150 microm) but different film thickness (50-200 microm) and different pore-to-pore distances (1 or 4 mm). The approximate dimensions of the hybrid vascular graft without the SPU film were as follows: inner diameter, 5 mm; length, 5 cm; thickness, 50 microm. The intraluminal pressure-external diameter relationship was measured by infusion of a phosphate buffer solution into the hybrid vascular graft. Canine carotid arteries and commercially available ePTFE grafts served as controls. Decrease in the thickness of the SPU film and increase in the pore density of the SPU film increased the pressure-dependent distensibility of the hybrid vascular grafts. The thinner the film and higher the pore density, the more compliant was the hybrid graft. The pressure-induced distensibility of the designed hybrid graft was found to be close to that of native carotid arteries.

A New Stent Graft

The use of stents improves the result after balloon coronary angioplasty. Restenosis due to neointimal hyperplasia and proliferation of smooth muscle cells are, however, a concern. In the present report, we studied the prevention of restenosis to allow endothelial cell migration and growth to proceed through micropores using our developed stent graft with micropored segmented polyurethane (SPU) thin film in a normal beagle model. Our developed stent graft was made from Palmaz stent and micropored SPU thin film. The SPU film was arranged into four different micropore densities around the circumference: no micropores, arrangement 4; micropores of 30mum in diameter with an orderly distance of 250mum; (arrangement 1), 500mum; (arrangement 2) and 125mum (arrangement 3) between the neighboring two pores. Micropores were made using the Excimer laser ablation technique. The Palmaz stent was wrapped with micropored film, sutured, and glued with DMF (dimethyl formamide) under aid of a microscope. These stents were placed in the common carotid arteries of beagles (n = 5). They were sacrificed at 1 month, and a histological study and scanning electron microscopy study were performed for evaluation of endoluminal endothelialization. In 10 arteries applied with stent grafts, there was no severe stenosis although it did occur to some extent. All stented arteries were patent. Endothelial cell migration and growth through micropores were observed histologically on micropored SPU thin film in this model, which did not affect the intraluminal diameter. In most non-porous regions, significant thrombi were found between the SPU film and the neointimal layer. On the other hand, in the porous region, little thrombosis was observed except in the lowest density region. In 125mum of distance between two neighboring pores, the neointimal layer was the thinnest, which was suitable for wide intraluminal space after placement of a stent graft. Endothelial cell migration and growth through micropores were confirmed in the animal model using our developed micropored stent graft. The proceeding of their migration was controlled by micropore density under a constant micropore diameter. The stent graft with micropored SPU thin film is promising for the prevention of restenosis due to neointimal hyperplasia.

Platelet adhesion onto segmented polyurethane film surfaces modified by addition and crosslinking of PEO-containing block copolymers

Polyethylene oxide (PEO) surfaces were prepared by the addition of PEO-containing amphiphilic block copolymers as surface modifying additives and of dicumyl peroxide (DCP) as a crosslinking agent in segmented polyurethane (PU). PEO-polypropylene oxide-PEO triblock copolymers (Pluronics) with different PEO chain length (from 0 to 98) were used as the surface modifying additives. The PEO additives in the PU film were then crosslinked to be stably entrapped in the PU matrix. The crosslinking was done by free radicals produced from the decomposition of DCP in the film through heating (120°C) or ultraviolet irradiation (254 nm). The surface properties of the PEO additive-entrapped PU films were investigated by the measurement of water contact angles and electron spectroscopy for chemical analysis. The bulk properties such as water absorption, long-term film stability, and tensile strength and elongation at break, were also investigated. It was observed that addition of a small amount (5 wt% based on PU) of the PEO additives resulted in a considerable change of surface characteristics. The PEO additives were stably entrapped in the PU films by crosslinking of them, without significant changes of bulk properties of the films. From the platelet adhesion test on the prepared PEO additive-containing film surfaces, it was observed that the platelet adhesion on the surfaces decreases with increase in PEO chain length of PEO additives. The film surface containing additive with long PEO chains (chain length of 98) was particularly effective in preventing platelet adhesion. The crosslinking of the PEO additives in PU films did not affect the behavior of platelet adhesion on the surfaces; the films with crosslinked PEO additives showed similar platelet adhesion on the surfaces to the films with uncrosslinked ones.