A high hydrostatic pressure method, which can apply over 600 MPa pressure was employed for preparing a hydrogel of poly(vinyl alcohol) (PVA) loaded with heparin. The aim of this study was to fabricate a heparin-PVA hydrogel conduit and evaluate its potential for vascular access. Heparin-PVA complex hydrogel showed suppressed heparin release and prevented clot formation, depending on the molecular weight of the PVA. Strength of the hydrogel conduit was increased by embedding a Dacron mesh between two PVA layers. The tubular heparin-PVA complex hydrogel displayed a burst pressure of 750 mmHg. The tubular heparin-PVA complex hydrogel did not show any occlusion or burst for 2 weeks after implantation, implying that this heparin-PVA complex hydrogel shows high potential for use as a vascular access. This is the first report on the preparation of a multilayered PVA hydrogel with heparin embedded on one side only. The proposed approach could be expanded to the fabrication of various biomaterials for specific purposes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/jbm.b.33121 | DOI Listing |
J Biomed Mater Res B Appl Biomater
October 2014
Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Chiyoda-ku, Tokyo, 101-0062, Japan.
A high hydrostatic pressure method, which can apply over 600 MPa pressure was employed for preparing a hydrogel of poly(vinyl alcohol) (PVA) loaded with heparin. The aim of this study was to fabricate a heparin-PVA hydrogel conduit and evaluate its potential for vascular access. Heparin-PVA complex hydrogel showed suppressed heparin release and prevented clot formation, depending on the molecular weight of the PVA.
View Article and Find Full Text PDFJ Biomed Mater Res
January 1993
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada.
Thrombin adsorption to polyvinyl alcohol (PVA) was different from its adsorption to polyethylene (PE)--not so much in amount, but in its affinity. Thrombin was more easily displaced from polyethylene and its adsorption was more readily prevented by prior or simultaneous exposure to albumin. From PVA (or heparin-PVA), only approximately 30% of the adsorbed protein could be removed by a series of eluents, including even harsh ones such as 2.
View Article and Find Full Text PDFJ Biomed Mater Res
July 1992
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada.
More radiolabeled thrombin was adsorbed to heparin-polyvinyl alcohol (PVA) than to PVA, consistent with a specific interaction with the immobilized heparin. The maximum surface concentration on heparin-PVA was estimated to be approximately 450 nmol/m2 with an apparent affinity constant (Ka) of 2.5 microM-1; on PVA, the plateau concentration was 10 nmol/m2 with a Ka less than 1 nM-1.
View Article and Find Full Text PDFJ Biomed Mater Res
August 1988
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada.
The diffusivities of thrombin and antithrombin III in a heparin-polyvinyl alcohol hydrogel were estimated and used to demonstrate that diffusion limits the effectiveness of the immobilized heparin in the interior of such hydrogels. Diffusivities were calculated from permeabilities and partition coefficients measured with films in a diffusion chamber apparatus. The diffusion coefficients were estimated to be 6 +/- 4 X 10(-8) cm2/s for thrombin and 4 +/- 2 X 10(-8) cm2/s for antithrombin III in 10% gel membranes with or without immobilized heparin.
View Article and Find Full Text PDFHeparin covalently-linked to polyvinyl alcohol (PVA) is a biomaterial which is of potential value as a non-thrombogenic coating. 125I-labelled thrombin adsorbed to heparin-PVA beads was not dislodged by phosphate-buffered saline, pH 7.4, although radioactivity was progressively displaced from the adsorbent by fibrinogen-free human plasma.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!