title: Time-resolved fluorescence spectroscopy and ultrasound backscatter microscopy for nondestructive evaluation of vascular grafts.
abstract: Quantitative and qualitative evaluations of structure and composition are important in monitoring development of engineered vascular tissue both in vitro and in vivo. Destructive techniques are an obstacle for performing time-lapse analyses from a single sample or animal. This study demonstrates the ability of time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM), as nondestructive and synergistic techniques, for compositional and morphological analyses of tissue grafts, respectively. UBM images and integrated backscatter coefficients demonstrate the ability to visualize and quantify postimplantation changes in vascular graft biomaterials such as loss of the external elastic lamina and intimal/medial thickening over the grafted region as well as graft integration with the surrounding tissue. TRFS results show significant changes in spectra, average lifetime, and fluorescence decay parameters owing to changes in collagen, elastin, and cellular content between normal and grafted tissue regions. These results lay the foundation for the application of a catheter-based technique for in vivo evaluation of vascular grafts using TRFS and UBM.
authors.affiliation: University of California Davis, Department of Biomedical Engineering, 451 East Health Sciences Drive, Davis, California 95616, United States.
authors.forename: Hussain
authors.initials: H
authors.lastname: Fatakdawala
authors.affiliation: University of California Davis, Department of Medicine and Epidemiology, VM2 Building, Davis, California 95618, United States.
authors.forename: Leigh G
authors.initials: LG
authors.lastname: Griffiths
authors.affiliation: University of California Davis, Department of Surgery, 2221 Stockton Boulevard, Sacramento, California 95817, United States.
authors.forename: Sterling
authors.initials: S
authors.lastname: Humphrey
authors.affiliation: University of California Davis, Department of Biomedical Engineering, 451 East Health Sciences Drive, Davis, California 95616, United States.
authors.forename: Laura
authors.initials: L
authors.lastname: Marcu
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D001807:Blood Vessel Prosthesis; D002339:Carotid Arteries / Q000737:chemistry* / Q000000981:diagnostic imaging* / Q000601:surgery; D059168:Carotid Intima-Media Thickness / Q000295:instrumentation*; D003094:Collagen / Q000032:analysis*; D004549:Elastin / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods; D013552:Swine
chemical_list: D003094:Collagen; D004549:Elastin