Analysis of urokinase immobilization on the polytetrafluoroethylene vascular prosthesis

Forster, Robert I.; Bernath, F. R.

doi:10.1016/s0002-9610(88)80372-6

Cited by 14 publications

(3 citation statements)

References 6 publications

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“…Antithrombogenic surfaces are obtained by the immobilization of biologically active substances with antithrombogenic activity, such as heparin, − urokinase, − prostaglandin derivatives, and human thrombomodulin. , Heparin immobilization has been achieved via ionic complex formation of heparin on cationically chargedpolymer substrates. , Release of heparin from the surface with time into blood eventually occurs, exposing the cationic polymer surface to the blood, which may cause massive platelet adhesion and aggregation resulting from electrostatic interactions with the exposed cationic charged surface. If a cationic graft polymer complicated with heparin is completely shielded or overlayered by a nonionic water-soluble polymer layer, cell adhesion on the device surfaces may be passively suppressed even after the heparin is completely released.…”

Section: Discussionmentioning

confidence: 99%

Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate

Nakayama

Matsuda

1999

Langmuir

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The photo-block-graft-copolymerization method using an iniferter, benzyl N,N-diethyldithiocarbamate, was utilized to design a biomedically functional surface for fabricated devices. Ultraviolet light irradiation under sequential charge of vinyl monomers, such as acrylic acid (AA), n-butyl methacrylate (BMA), N,N-dimethylacrylamide (DMAAm), N-[3-(dimethylamino)propyl]acrylamide (DMAPAAm), or styrene (ST), produced block-grafted surfaces, in which different polymer blocks were sequentially formed on polyST (PST) partially derivatized with N,N-diethyldithiocarbamate groups. Examination of a cross-sectional view under a transmission electron microscope (TEM) revealed a bilayered structure of the PST-b-PDMAAm block-graft copolymer. Three different AB-type block-graft-copolymerized surfaces were prepared for biomedical applications, where block A was the bottom layer and block B the top layer: (1) For heparin immobilization, a polyPDMAPAAm (PDMAPAAm) (A)−polyDMAAm (PDMAAm) (B) block-graft-copolymerized surface was prepared, where the block A layer contained ionically immobilized heparin and the block B layer functioned as a protective layer to suppress protein adsorption and cell adhesion. (2) For protein immobilization, a PDMAAm (A)-polyAA (PAA) (B) block-graft-copolymerized surface was prepared, where the block B layer covalently fixed the protein and the block A layer functioned as a protective layer to prevent contact of the protein with the substrate. (3) For a drug-releasing surface, a PDMAAm (A)-polyBMA (PBMA) (B) block-graft-copolymerized surface was prepared, where the block A layer contained the drug and the block B layer functioned as a barrier to regulate drug release. These macromolecularly designed surfaces were characterized by X-ray photoelectron spectroscopy, and the immobilization of heparin and protein was visualized by light microscopy, after staining with toluidine blue (for heparin), and fluorescence microscopy (for protein).

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Section: Discussionmentioning

confidence: 99%

Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate

Nakayama

Matsuda

1999

Langmuir

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“…These approaches generally reduce fibrin formation, but have little or even detrimental effects on platelet activation [32,36]. Thrombolytic agents such as urokinase have also been immobilized onto blood contacting biomaterials via ionic complexes [40,41]. In addition, several immobilized antiplatelet techniques have reduced the in vitro levels of platelet adhesion and aggregation to polymer surfaces [42,43].…”

Section: Prevention Of Graft Thrombosismentioning

confidence: 99%

Effect of Controlled Local Acetylsalicylic Acid Release on in vitro Platelet Adhesion to Vascular Grafts

1994

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Thrombosis is the most serious acute problem for small diameter arterial bypass grafts. In this research, small diameter expanded polytetrafluoroethylene (e-PTFE) vascular grafts were coated with acetylsalicylic acid (ASA) loaded poly (d,l-lactide) (PLA) by a solvent casting method. The feasibility and efficacy of this approach were evaluated by ASA release studies and platelet adhesion tests. First, the ASA release kinetics were evaluated from the ASA/PLA coated vascular grafts in an in vitro steady flow loop model. ASA release was measured by a spectrophotometric technique. Finally, the efficacy of local ASA release to reduce in vitro canine platelet adhesion to grafts was determined with epifluorescent video microscopy and quantitative image analysis. The steady state release rates from the 5%, 10%, and 15% ASA/PLA coated grafts were 13.2 x 10(-5), 32.0 x 10(-5), and 41.5 x 10(-5) micrograms/cm2.sec, respectively. Platelet adhesion to 10% and 15% ASA/PLA coated grafts was reduced with respect to the control and 5% grafts for 10 days. Platelet adhesion to 5% ASA/PLA coated grafts was reduced with respect to controls at 2 and 10 days, but not initially.

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“…For this purpose, a 2‐methacryloyloxyethyl phosphorylcholine (MPC)‐based polymer (MPC polymer) and poly(ethylene glycol) (PEG) among others, have been successfully used for medical devices. The other approach is to immobilize a bioactive substance on the material surface that has anticoagulative activity, such as heparin, factor H, or urokinase . In particular, MPC polymer and heparin are two of the most successful non‐thrombogenic materials presently available for clinical medical devices.…”

Section: Introductionmentioning

confidence: 99%

Validation of an MPC Polymer Coating to Attenuate Surface‐Induced Crosstalk between the Complement and Coagulation Systems in Whole Blood in In Vitro and In Vivo Models

Asif

Asawa

Inoue

et al. 2019

Macromolecular Bioscience

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HemocompatibilityArtificial surfaces that come into contact with blood induce an immediate activation of the cascade systems of the blood, leading to a thrombotic and/ or inflammatory response that can eventually cause damage to the biomaterial or the patient, or to both. Heparin coating has been used to improve hemocompatibility, and another approach is 2-methacryloyloxyethyl phosphorylcholine (MPC)-based polymer coatings. Here, the aim is to evaluate the hemocompatibility of MPC polymer coating by studying the interactions with coagulation and complement systems using human blood in vitro model and pig in vivo model. The stability of the coatings is investigated in vitro and MPC polymer-coated catheters are tested in vivo by insertion into the external jugular vein of pigs to monitor the catheters' antithrombotic properties. There is no significant activation of platelets or of the coagulation and complement systems in the MPC polymer-coated one, which was superior in hemocompatibility to non-coated matrix surfaces. The protective effect of the MPC polymer coat does not decline after incubation in human plasma for up to 2 weeks. With MPC polymer-coated catheters, it is possible to easily draw blood from pig for 4 days in contrast to the case for non-coated catheters, in which substantial clotting is seen.

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Analysis of urokinase immobilization on the polytetrafluoroethylene vascular prosthesis

Cited by 14 publications

References 6 publications

Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate

Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate

Effect of Controlled Local Acetylsalicylic Acid Release on in vitro Platelet Adhesion to Vascular Grafts

Validation of an MPC Polymer Coating to Attenuate Surface‐Induced Crosstalk between the Complement and Coagulation Systems in Whole Blood in In Vitro and In Vivo Models

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