Vascular graft healing. III. FTIR analysis of ePTFE graft samples from implanted bigrafts.
A bigraft, composed of a 30-microm internodal distance expanded polytetrafluoroethylene (ePTFE) arterial graft segment and a preclotted polyethylene terephthalate arterial graft segment, was used to study the healing process of two different materials in the same dog. Healing was followed by FTIR-ATR spectroscopy and correlated with ELISA analyses of selected growth factors and matrix proteins. The FTIR analyses of the ePTFE explants from 1 and 3 h; 3, 5, 7, 10, and 14 days; and 4 and 8 weeks showed that the ePTFE grafts did not heal (endothelialize), but appeared to remain in overlapping inflammation and proliferation stages of wound healing. Although FN was found in the fibrin layer coating the luminal surface of the ePTFE, VEGF was not present. The inability of VEGF to complex with FN may be the result of FN binding sites being blocked or hidden by the conformation of the fibrin clot that forms on ePTFE. Also, TGF-beta was not present beyond the initial clot formation at 3 h postimplantation. The absence of these two growth factors may be an important factor in the lack of healing of 30-microm ePTFE grafts, because both were found to be present during the early stages of healing for the preclotted polyester grafts that did endothelialize.
Murray-Wijelath
Jacqueline
J
Department of Polymer Chemistry, The Hope Heart Institute, Seattle, Washington 98122, USA.
Lyman
Donald J
DJ
Wijelath
Errol S
ES
D000818:Animals; D001769:Blood; D001777:Blood Coagulation; D001807:Blood Vessel Prosthesis; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005353:Fibronectins / Q000378:metabolism; D008422:Materials Testing; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene; D017550:Spectroscopy, Fourier Transform Infrared; D013895:Thoracic Arteries / Q000601:surgery; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014945:Wound Healing
D005353:Fibronectins; D011093:Polyethylene Terephthalates; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D011138:Polytetrafluoroethylene