Improvement of blood compatibility on cellulose dialysis membrane. 2. Blood compatibility of phospholipid polymer grafted cellulose membrane

Preliminary Investigation on Efficacy and Safety of Substance P-Coated Stent for Promoting Re-Endothelialization: A Porcine Coronary Artery Restenosis Model

BACKGROUND

Current polymer-based drug-eluting stents (DESs) have fundamental issues about inflammation and delayed re-endothelializaton of the vessel wall. Substance-P (SP), which plays an important role in inflammation and endothelial cells, has not yet been applied to coronary stents. Therefore, this study compares poly lactic-co-glycolic acid (PLGA)-based everolimus-eluting stents (PLGA-EESs) versus 2-methacryloyloxyethyl phosphorylcholine (MPC)-based SP-eluting stents (MPC-SPs) in in-vitro and in-vivo models.

METHODS

The morphology of the stent surface and peptide/drug release kinetics from stents were evaluated. The in-vitro proliferative effect of SP released from MPC-SP is evaluated using human umbilical vein endothelial cell. Finally, the safety and efficacy of the stent are evaluated after inserting it into a pig's coronary artery.

RESULTS

Similar to PLGA-EES, MPC-SP had a uniform surface morphology with very thin coating layer thickness (2.074 μm). MPC-SP showed sustained drug release of SP for over 2 weeks. Endothelial cell proliferation was significantly increased in groups treated with SP (n = 3) compared with the control (n = 3) and those with everolimus (n = 3) (SP: 118.9 ± 7.61% vs. everolimus: 64.3 ± 12.37% vs. the control: 100 ± 6.64%, p < 0.05). In the animal study, the percent stenosis was higher in MPC-SP group (n = 7) compared to PLGA-EES group (n = 7) (MPC-SP: 28.6 ± 10.7% vs. PLGA-EES: 16.7 ± 6.3%, p < 0.05). MPC-SP group showed, however, lower inflammation (MPC-SP: 0.3 ± 0.26 vs. PLGA-EES: 1.2 ± 0.48, p < 0.05) and fibrin deposition (MPC-SP: 1.0 ± 0.73 vs. PLGA-EES: 1.5 ± 0.59, p < 0.05) around the stent strut. MPC-SP showed more increased expression of cluster of differentiation 31, suggesting enhanced re-endothelialization.

CONCLUSION

Compared to PLGA-EES, MPC-SP demonstrated more decreased inflammation of the vascular wall and enhanced re-endothelialization and stent coverage. Hence, MPC-SP has the potential therapeutic benefits for the treatment of coronary artery disease by solving limitations of currently available DESs.

Polymeric biomaterials: influence of phosphorylcholine polar groups on protein adsorption and complement activation

The introduction to polymeric biomaterials of phosphorylcholine polar groups represents an approach towards the development of materials with improved blood compatibility. In this respect, two biomaterials, one a copolymer of butyl methacrylate and 2-methacryloyloxyethylphosphorylcholine (MPC), (poly(BMA-co-MPC) and the other, MPC-grafted Cuprophan, were examined with respect to their influence on protein adsorption and complement activation. Protein adsorption was studied by measurement of the adsorption of radiolabelled single proteins (albumin and fibrinogen), while complement activation was measured using radioimmunoassay for C3a des Arg. The investigation demonstrated that the polymers containing phosphorylcholine polar groups can achieve a marked reduction in protein adsorption and complement activation and supports the utilization of phosphorylcholine polar groups as a means of improving the compatibility of biomaterials for blood-contacting applications.

Phosphorylation of bio-based compounds: the state of the art

The aim of this review is to present both fundamental and applied research on the phosphorylation of renewable resources, through reactions on naturally occurring functions, and their use in biobased polymer chemistry and applications.

Haemocompatibility of titanium and its alloys

This review outlines the current understanding of the interactions of titanium and its alloys with blood components, and the ways in which surface modification techniques can be used to alter the surface physicochemical and topographical features that determine blood-material interactions. Surface modification of the spontaneously formed titanium oxide surface layer is a highly attractive means of improving haemocompatibility without forgoing the advantageous mechanical and physical properties of titanium and its alloys. A number of surface modification techniques and treatment processes are discussed in the context of enhancing the haemocompatibility of titanium and its alloys, with a view to optimising the clinical efficacy of blood-contacting devices and materials.

Grafting copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) onto pre-irradiated cellulose films

Grafting of 2-methacryloyloxyethyl phosphorylcholine (MPC) and poly(ethylene glycol mathacrylate) (PEGMA) onto cellulose films was performed using the pre-irradiation grafting method. The effects of monomer concentration, solvent system and co-solvent composition, and reaction time on the degree of grafting were determined. The grafted samples were confirmed by FT-IR-ATR spectra. The blood compatibilities of the grafted cellulose were evaluated by platelet-rich plasma contact studies and viewed by scanning electron microscopy; non-grafted cellulose film sample was used as references. As a result, MPC and MPC/PEGMA were grafted on the surface of cellulose films. It was found that fewer platelets adhered to the MPC-grafted surfaces and that they showed less shape variation than the ungrafted references.

Interface of covalently bonded phospholipids with a phosphorylcholine head: characterization, protein nonadsorption, and further functionalization

Surface anchored poly(methylhydrosiloxane) (PMHS) thin films on oxidized silicon wafers or glass substrates were functionalized via the SiH hydrosilylation reaction with the internal double bonds of 1,2-dilinoleoyl-sn-glycero-3-phosphorylcholine (18:2 Cis). The surface was characterized by X-ray photoelectron spectroscopy, contact angle measurements, atomic force microscopy, and scanning electron microscopy. These studies showed that the PMHS top layer could be efficiently modified resulting in an interfacial high density of phospholipids. Grafted phospholipids made the initially hydrophobic surface (θ = 106°) very hydrophilic and repellent toward avidin, bovine serum albumin, bovine fibrinogen, lysozyme, and α-chymotrypsin adsorption in phosphate saline buffer pH 7.4. The surface may constitute a new background-stable support with increased biocompatibility. Further possibilities of functionalization on the surface remain available owing to the formation of interfacial SiOH groups by Karstedt-catalyzed side reactions of SiH groups with water. The presence of interfacial SiOH groups was shown by zeta potential measurements. The reactivity and surface density of SiOH groups were checked by fluorescence after reaction of a monoethoxy silane coupling agent bearing Alexa as fluorescent probe.

Preparation of blood-compatible hollow fibers from a polymer alloy composed of polysulfone and 2-methacryloyloxyethyl phosphorylcholine polymer

Blood-compatible hollow fibers were successfully prepared from a polymer alloy composed of polysulfone (PSf) and the 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. To improve the hydrophilicity, fouling-resistance characteristics, and blood compatibility of the PSf hollow fiber in a hemodialyzer, an MPC polymer that can be blended with PSf was synthesized in order to prepare the polymer alloy (PSf/MPC polymer). The contents of the MPC polymer blended in the PSf were 7 and 15 wt%. The PSf/MPC polymer hollow fiber could be prepared by both wet and dry-wet processing methods. The hollow fiber took an asymmetric structure, that is, the hollow-fiber membrane had a dense skin layer on the porous sponge-like structure. The mechanical strength was higher than that of conventional PSf hollow fibers for hemodialysis. The surface characterization of the PSf/MPC polymer hollow fiber by x-ray photoelectron spectroscopy revealed that the MPC units were concentrated at the surface. The permeability for solutes through the PSf/MPC polymer hollow fibers was measured for 4 h. The permeabilities of both a low-molecular-weight compound and protein were greater than those of the PSf hollow fibers. The amount of adsorbed protein was lower on the PSf/MPC polymer hollow fiber when compared to that of the PSf hollow fiber. Moreover, platelet adhesion was also effectively inhibited on the PSf/MPC polymer hollow fiber. Based on these results, the addition of the MPC polymer to the PSf is a very useful method to improve the functions and blood compatibility of the hollow fiber.

Preparation of non-thrombogenic materials using 2-methacryloyloxyethyl phosphorylcholine

This review addresses the non-thrombogenic characteristics of copolymers based on 2-methacryloyloxyethyl phosphorylcholine (MPC), originally developed by Nakabayashi and colleagues. The hypothesis underlying these developments was that such materials would adsorb phospholipids from blood, yielding surfaces with good natural blood compatibility. Methacrylates were found to have excellent properties for this copolymerisation. The characteristics of the MPC copolymers relevant to the improved blood compatibility were minimisation of protein adsorption through an increase in the amount of free water in the MPC hydrogels, which prevents protein conformational change and increased protein stability in solution. Non-thrombogenicity has been evaluated by in vitro, ex vivo and in vivo procedures. Non-thrombogenic dialysis membranes and a durable glucose biosensor have been developed using this MPC copolymer.

Modification of polymer surfaces: optimization of approaches

Modification of polymer surfaces to achieve a surface with enhanced compatibility is an important means of obtaining improved biomaterials. Techniques are available for altering the hydrophilicity or charge of a surface, attaching macromolecules or attempting to resemble cell membranes. Relevant to the clinical success of a modified surface is the modification procedure and a procedure based on incorporation as opposed to surface treatment has potential advantages. The modification of plasticized vinyl chloride (PVC) by the incorporation of cyclodextrins is described. In comparison to unmodified PVC controls, cyclodextrin incorporation reduced fibrinogen adsorption, with the extent of reduction dependent on the type and quantity of cyclodextrin incorporated.

Protein adsorption-resistant hollow fibers for blood purification

Nonfouling polysulfone (PSf) hollow fiber membranes resistant to protein adsorption and deposition were newly developed by the addition of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer. To improve hydrophilicity, permeability, and nonfouling characteristics of the PSf hollow fiber in a hemodialyzer, we synthesized a MPC polymer which can be blended with PSf for preparing the polymer alloy (PSf/MPC polymer). The composition of the MPC polymer blended in the PSf was in the range between 7.0 and 15 wt%. From the PSf/MPC polymer solution, flat membranes and hollow fibers could be prepared. These membranes took an asymmetric structure, and its mechanical strength was good. The surface characterization of the PSf/MPC polymer hollow fiber membrane by X-ray photoelectron spectroscopy revealed that the MPC units were concentrated at the surface. The permeability for solutes through the PSf/MPC polymer membrane was higher, and the amount of protein adsorbed on the PSf/MPC polymer membrane was lower than those of the PSf membrane. Moreover, platelet adhesion was also effectively inhibited on the PSf/MPC polymer membrane.

Photoinduced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on polyethylene membrane surface for obtaining blood cell adhesion resistance

Phospholipid polymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)], was grafted with polyethylene (PE) membrane using photoinduced polymerization technique to make the membrane resistant to cell adhesion. The water contact angle on the PE membrane grafted with poly(MPC) decreased with an increase in the photopolymerization time. This decrease corresponded to the increase in the amount of poly(MPC) grafted on the PE surface. The same graft polymerization procedure was applied using other hydrophilic monomers, such as acrylamide (AAm), N-vinylpyrrolidone (VPy) and methacryloyl poly(ethylene glycol) (MPEG). These monomers were also polymerized to form grafted chains on the PE membrane, and the grafting was confirmed with X-ray photoelectron spectroscopy. Analysis of amount and distribution of plasma proteins at the plasma-contacting surface of the original and the modified PE membranes were analyzed using immunogold assay. The grafting of poly(MPC) and poly(VPy) on PE membrane reduced the plasma protein adsorption significantly compared with that on the original PE membrane. However, the PE membranes grafted with poly(AAm) or poly(MPEG) did not show any effects on protein adsorption. Platelet adhesion on the original and modified PE membranes from platelet-rich plasma was also examined. A large number of platelets adhered and activated on the original PE membrane. Grafting with poly(AAm) did not suppress platelet adhesion, but grafting with poly(MPC) or poly(VPy) on the PE membrane was effective in preventing platelet adhesion. It is concluded that the introduction of the phosphorylcholine group on the surface could decrease the cell adhesion to substrate polymer.

Chemical modification of silk fibroin with 2-methacryloyloxyethyl phosphorylcholine. II. Graft-polymerization onto fabric through 2-methacryloyloxyethyl isocyanate and interaction between fabric and platelets

2-Methacryloyloxyethyl phosphorylcholine (MPC) was grafted onto silk fabric in a two-step heterogeneous system through the vinyl bonds of 2-methacryloyloxyethyl isocyanate (MOI) modified on the fabric. First, habutae silk fabric was modified with the MOI monomer in anhydrous dimethyl sulfoxide using di-n-butyltin (IV) dilaurate and hydroquinone at 35 degrees C. The saturated weight gain of modified MOI monomer on the fabric was 7.3 wt% versus the original silk. Second, graft polymerization with MPC onto the MOI modified silk was conducted using 2,2'-azo bis[2-(2-imidazolin-2-yl)propane dihydrochloride] (VA-044) as an azo polymerization initiator. The weight of the grafted MPC eventually gained was about 26.0 wt%. The MOI-modified and MPC-grafted silk fabrics were analyzed by Fourier transform infrared (FT-IR) spectroscopy. To confirm the improved biocompatibility of the silk fabric, platelet adhesion was preliminarily tested measuring lactate dehydrogenase. The number of platelets adhering to polyMPC-grafted silk fabric decreased by about one tenth compared to original and MOI-modified silk after 60 min of contact with human platelet-rich plasma (1.0 x 10(6) platelets cm(-2)).

The effect of the chemical structure of the phospholipid polymer on fibronectin adsorption and fibroblast adhesion on the gradient phospholipid surface

The interaction between biocomponents and the polyethylene (PE) surface modified with poly[omega-methacryloyloxyalkyl phosphorylcholine (MAPC)] was considered taking into account the surface characteristics, i.e., density, mobility, and orientation of the poly(MAPC). The PE surface, grafted gradually with the poly(MAPC) was prepared by corona irradiation method. The amount of peroxide produced on the PE surface which was determined with 1,1-diphenyl-2-picryl-hydrazyl, increased with an increase in the energy of the corona. The surface density of the poly(MAPC) was increased with an increase in the amount of the peroxides produced by the corona irradiation. The orientation and mobility of the poly(MAPC) grafted on the PE surface was evaluated with 1,6-diphenyl-1,3,5-hexatriene. The orientation of the poly[6-methacryloyloxyhexyl phosphorylcholine (MHPC)] which has six methylene chains between the phospholipid polar group and the backbone was higher than that of other poly(MAPC)s. The mobility of the poly(MAPC) decreased with an increase in the methylene chain length in the MAPC unit. The fibronectin adsorption on the gradient PE sheet grafted with poly(MAPC) was determined with enzyme-labeled immunoassay. The amount of adsorbed fibronectin on the PE grafted with poly[2-methacryloyloxyethyl phospohorylcholine(MPC)] and poly(MHPC) decreased with an increase in their surface density. Especially, the PE sheet grafted with the poly(MHPC) was effectively reduced compared with other poly(MAPC)s. On the poly[10-methacryloyloxydecyl phosphorylcholine (MDPC)], there is a minimum amount of adsorbed fibronectin. The fibronectin adsorption pattern on the PE sheet grafted with poly(MAPC) was quite different from the chemical structure of the MAPC unit. The human normal diploid fibroblasts (WI-38 cells) were cultured on the gradient PE sheet grafted with poly(MAPC) changing the concentration of seeded WI-38 cells. The adhesion behavior of the WI-38 cells was different depending on the concentration of the seeded WI-38 cells. When the concentration was low, the number of the adherent WI-38 cells had the same tendency as fibronectin adsorption. The gradient PE sheet grafted with the poly(MHPC) effectively reduced WI-38 cells adhesion even when the concentration of the WI-38 cells was high. The biocompatibility of polymer surfaces can be improved by highly oriented phosphorylcholine group.

Improvement of blood compatibility on cellulose hemodialysis membrane: IV. Phospholipid polymer bonded to the membrane surface

To improve the surface blood compatibility on a cellulose hemodialysis membrane, 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers with a phospholipid polar group were immobilized on the surface through covalent bonding. The MPC polymers had a carboxylic group, which can react with hydroxyl groups on the cellulose membrane, and were synthesized by conventional radical polymerization. The reaction between the MPC polymers and the cellulose membrane was carried out in a heterogeneous system using a condensation reagent. Surface analysis of the modified membrane by X-ray photoelectron spectroscopy revealed the immobilization of the MPC polymer on the surface. The mechanical strength and permeability for a solute of the membrane did not change even after the modification. The modified cellulose membrane was blood-compatible, as determined by the prevention of adhesion, deformation, and aggregation of platelets after contact with platelet-rich plasma. Based on these results, it is concluded that the MPC polymers may be a useful material for improving the blood compatibility of cellulose hemodialysis membranes.

Biocompatibility in cardiopulmonary bypass

Recent advances in surgical techniques and perfusion technology allow cardiac operations to be performed routinely with low mortality rates. However, patients undergoing cardiac operations with cardiopulmonary bypass (CPB) are still associated with bleeding disorders, thrombotic complications, massive fluid shifts, and the activation of blood components that are collectively known as the whole body inflammatory response. In this review, the effect of cardiopulmonary bypass on various humoral and cellular components of blood is examined. Blood activation caused by interaction with artificial materials of extracorporeal circuit and by material-independent stimuli is discussed. Methods to control blood activation during and after cardiopulmonary bypass are described. These include surface modification of extracorporeal circuit, control of flow dynamics in the circuit, pharmacological intervention, and the use of extracorporeal devices to remove inflammatory mediators. Recent findings on the effects of heparin-coated circuits on inflammatory response and clinical outcome are reviewed. It appears that the causes of inflammatory response to cardiopulmonary bypass are multifactorial and that an integrated strategy is needed to control and eliminate the negative effects of CPB.

Permeability and blood compatibility properties of chitosan-poly(ethylene oxide) blend membranes for haemodialysis

Chitosan-poly(ethylene oxide) (PEO) blend membranes, using different molecular weights of PEO, were developed for improved permeability and blood compatibility. The equilibrium hydration increased from 44.7% for chitosan to 62.5% for chitosan-PEO blend membranes when the molecular weight of PEO was 10,000 (10K) or higher. An increase in the hydration of PEO blend membranes was due to intermolecular association between PEO and chitosan chains. Scanning electron microscopy showed that chitosan-PEO membranes were highly porous with size ranging from 50 to 80 nm in diameter observed in membranes made with PEO10K. Electron spectroscopy for chemical analysis suggested an increase in PEO on the membrane surface with increasing molecular weight in the blend. The permeability coefficient of urea increased from 5.47 x 10(-5) cm2 min-1 in chitosan to 9.86 x 10(-5) cm2 min-1 in chitosan-PEO10K membranes. The increase in permeability coefficient could be either due to an increase in the hydrophilicity or the high porosity of the membranes. Although chitosan-PEO membranes did not prevent serum complement activation, platelet adhesion and activation were significantly reduced. Chitosan-PEO blend membranes, therefore, appear to be beneficial in improving the permeability of toxic metabolites and in reducing the thrombogenicity for haemodialysis.

Improvement of blood compatibility on cellulose dialysis membrane. III. Synthesis and performance of water-soluble cellulose grafted with phospholipid polymer as coating material on cellulose dialysis membrane

To improve the surface blood compatibility on a cellulose hemodialysis membrane, a blood compatible polymer with a phospholipid polar group, poly[2-methacryloyloxyethyl phosphorylcholine(MPC)], was immobilized on the surface through the coating of a water-soluble cellulose grafted with poly(MPC) (MPC-grafted cellulose, MGC). The MGC was synthesized by graft copolymerization of MPC on a water-soluble cellulose using cerium ion as an initiator. The coating process on the cellulose membrane with an aqueous solution of the MGC was convenient, and the MGC on the surface was not significantly detached even after immersion in water. The permeability and mechanical strength of the membrane coated with the MGC did not decrease compared with the original membranes. The MGC-coated cellulose membrane was blood compatible, as determined by the prevention of platelet adhesion and aggregation after contact with platelet-rich plasma. From these results, it is concluded that the MGC may be a useful material for improving the blood compatibility of the cellulose hemodialysis membrane.

Selective adhesion of platelets on a polyion complex composed of phospholipid polymers containing sulfonate groups and quarternary ammonium groups

We investigated the effects of electrical charges on cell-polymer interactions of poly[2-methacryloyloxyethyl phosphorylcholine(MPC)-co-n-butyl methacrylate (BMA)] (PMB) having excellent blood compatibility, by copolymerizing anionic or cationic methacrylates with MPC and BMA. A polyion complex (PIC) composed of anionic and cationic MPC copolymers was also prepared. When the cell adhesion on these polymer surfaces from rabbit whole blood was evaluated, we observed a considerable reduction in cell adhesion on the MPC copolymers compared with that on poly(BMA), even when the MPC copolymer was electrically charged. On the other hand, many platelets selectively adhered to the PIC surface from whole blood, but the adherent platelets maintained a discoid shape. The amount of adenosine triphosphate (ATP) in platelets adherent on the PMB or the PIC from a platelet-rich plasma (PRP) was more than 75% of that in the original PRP, which indicated that the activity of these platelets remained high. However, in the platelets adherent to poly(BMA), only a small amount of ATP remained. Protein adsorption on the polymer surface from human plasma was investigated using a gold-colloid-labeled immunoassay against albumin gamma-globulin, and fibrinogen. Many of these proteins adsorbed on poly(BMA), whereas a small amount of protein was observed on the MPC copolymers that had an electrical charge. Albumin adsorption and suppression of gamma-globulin and fibrinogen adsorption were found on the PIC. Therefore, the introduction of electrical charges in the PMB did not have an adverse effect on cell adhesion and protein adsorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of hemocompatibility on a cellulose dialysis membrane with a novel biomedical polymer having a phospholipid polar group

To improve surface hemocompatibility on cellulose hollow fibers for hemodialysis, newly designed hemocompatible polymers with a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers, were introduced on the surface through two different methods: direct grafting of MPC on the surface, or coating of a water-soluble cellulose grafted with MPC. The MPC was polymerized using cerium ion as an initiator in the cellulose hollow fibers, and the poly(MPC) chains were grafted directly on the surface. Another modification of the cellulose hollow fibers was attempted by coating them with a water-soluble graft copolymer composed of a poly(MPC) side chain and a cellulose backbone. The coating process from an aqueous solution of the graft copolymer was very convenient, and the graft copolymer on the surface was not detached even after water circulated into the hollow fibers. These cellulose hollow fibers modified with MPC polymers displayed excellent hemocompatibility such as prevention of blood cell adhesion and aggregation after contact with blood without an anticoagulant. The permeability of the hollow fibers did not decrease as a result of these modifications. From these results, it is clearly suggested that introduction of the MPC units was effective for improving the hemocompatibility of the hollow fibers for hemodialysis.

Biomaterials for blood-contacting applications

Consideration of biomaterials for blood-contacting applications should take into account blood-biomaterial interactions, factors influencing the blood response and evaluation procedures. Examination of blood-biomaterial interactions indicates that relevant features are protein adsorption, platelet reactions, intrinsic coagulation, fibrinolytic activity, erythrocytes, leucocytes and complement activation. Factors influencing the blood response to a biomaterial in clinical application are the biomaterial structure, the presence of an antithrombotic agent, the patient status as determined by the disease and drug therapy, and the nature of the application. Evaluation options for biomaterials are clinical, in vivo, ex vivo and in vitro, with ex vivo and in vitro procedures relevant for biomaterial development.

Hemocompatibility on graft copolymers composed of poly(2-methacryloyloxyethyl phosphorylcholine) side chain and poly(n-butyl methacrylate) backbone

To improve the hemocompatibility on hydrophobic biomedical materials by a simple coating technique, graft copolymers composed of a hydrophilic side chain with phospholipid polar groups and a hydrophobic backbone were synthesized. The hydrophilic chain had phospholipid polar groups, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)], and the hydrophobic backbone was poly[n-butyl methacrylate (BMA)]. Because the graft copolymers obtained could dissolve in ethanol, they could be used as a coating material. When the poly(MPC-graft-BMA) was coated onto a poly(BMA) membrane, the composition of the MPC units on the surface was maintained in the bulk graft copolymer even after immersion in water. Protein adsorption on the membrane coated with the graft copolymer from human plasma detected by a gold-colloid labeled immunoassay was drastically decreased compared with that on glass and the original membrane. Moreover, blood cell adhesion, activation, and aggregation on the membrane after contact with human citrated whole blood were suppressed by the coating of the graft copolymer. These results clearly show that the poly(MPC-graft-BMA) is a suitable material for improving hemocompatibility on the biomedical devices because of its protein adsorption and cell adhesion resistant properties.