TY - JOUR
T1 - In vitro exposure of a novel polyesterurethane graft to enzymes
T2 - a study of the biostability of the Vascugraft® arterial prosthesis
AU - Zhang, Ze
AU - King, Martin
AU - Guidoin, Robert
AU - Therrien, Marie
AU - Doillon, Charles
AU - Diehl-Jones, William L.
AU - Huebner, Erwin
N1 - Funding Information:
This work has been supported in part by the MRC of Canada, the Quebec Heart Foundation and Braun Melsungen AG. We would like to extend our gratitude to Pierre Audet, Suzanne Bourassa, Karen Horth, Claire Letendre and Rodica Plesu for their technical assistance. We would also like to thank Alain Adnot, Maryse Julien, Yves Marois and Catherine Rolland for their helpful advice and support. We are also indebted to Drs H.E. Kniepkamp, B. Braun, P.U. Grande and R.T. Grundmann for helpful discussions.
PY - 1994/11
Y1 - 1994/11
N2 - The biostability of the Vascugraft® arterial prosthesis, a porous synthetic graft made by a novel spinning process from a unique poly(ester urethane) polymer, has been studied by means of an in vitro enzyme incubation technique. Samples of the Vascugraft® were exposed to buffered solutions of collagenase and pancreatin, as well as the buffer solutions alone, for periods of up to 100 days at 37 ± 1°C. On removal and after cleaning, a number of different analytic methods, including X-ray photoelectron spectroscopy for chemical analysis (ESCA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), scanning electron microscopy (SEM), interference microscopy, moisture content and contact angle measurements, were used to examine the changes in chemical structure and surface morphology of the samples. During incubation in both enzymes the molecular weight of the polyurethane appeared to decrease in the presence of enzyme but increase in the presence of buffer. Further microphase separation in the polyurethane material developed during incubation in buffer solutions. Such changes in microstructure were associated with increased surface hydrophilicity, increased moisture content and a significant improvement in the extent of order and preferred orientation of the hard segment domains within the fibres. In the sampling depth of about 5 nm, both enzymes decreased the carbonate group content at the surface of the prosthesis to as little as 40% of their original values. The results from ATR-FTIR and DSC demonstrated that this phenomenon was limited primarily to the soft segment phase. While the Vascugraft® prosthesis did exhibit some limited chemical modifications on exposure to concentrated enzyme solutions, nevertheless such changes were confined to the surface layer of the polyurethane microfibres. The importance and significance of those results will be more adequately determined by in vivo investigation.
AB - The biostability of the Vascugraft® arterial prosthesis, a porous synthetic graft made by a novel spinning process from a unique poly(ester urethane) polymer, has been studied by means of an in vitro enzyme incubation technique. Samples of the Vascugraft® were exposed to buffered solutions of collagenase and pancreatin, as well as the buffer solutions alone, for periods of up to 100 days at 37 ± 1°C. On removal and after cleaning, a number of different analytic methods, including X-ray photoelectron spectroscopy for chemical analysis (ESCA), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), size exclusion chromatography (SEC), scanning electron microscopy (SEM), interference microscopy, moisture content and contact angle measurements, were used to examine the changes in chemical structure and surface morphology of the samples. During incubation in both enzymes the molecular weight of the polyurethane appeared to decrease in the presence of enzyme but increase in the presence of buffer. Further microphase separation in the polyurethane material developed during incubation in buffer solutions. Such changes in microstructure were associated with increased surface hydrophilicity, increased moisture content and a significant improvement in the extent of order and preferred orientation of the hard segment domains within the fibres. In the sampling depth of about 5 nm, both enzymes decreased the carbonate group content at the surface of the prosthesis to as little as 40% of their original values. The results from ATR-FTIR and DSC demonstrated that this phenomenon was limited primarily to the soft segment phase. While the Vascugraft® prosthesis did exhibit some limited chemical modifications on exposure to concentrated enzyme solutions, nevertheless such changes were confined to the surface layer of the polyurethane microfibres. The importance and significance of those results will be more adequately determined by in vivo investigation.
KW - Vascular prostheses
KW - enzymes
KW - polyurethanes
KW - surface characterization
UR - http://www.scopus.com/inward/record.url?scp=0028533689&partnerID=8YFLogxK
U2 - 10.1016/0142-9612(94)90233-X
DO - 10.1016/0142-9612(94)90233-X
M3 - Journal Article
C2 - 7893915
AN - SCOPUS:0028533689
SN - 0142-9612
VL - 15
SP - 1129
EP - 1144
JO - Biomaterials
JF - Biomaterials
IS - 14
ER -