title: Elastic fiber production in cardiovascular tissue-equivalents.
abstract: Elastic fiber incorporation is critical to the success of tissue-engineered arteries and heart valves. Elastic fibers have not yet been observed in tissue-engineered replacements fabricated in vitro with smooth muscle cells. Here, rat smooth muscle cells (SMC) or human dermal fibroblasts (HDF) remodeled collagen or fibrin gels for 4 weeks as the basis for a completely biological cardiovascular tissue replacement. Immunolabeling, alkaline extraction and amino acid analysis identified and quantified elastin. Organized elastic fibers formed when neonatal SMC were cultured in fibrin gel. Fibrillin-1 deposition occurred but elastin was detected in regions without fibrillin-1, indicating that a microfibril template is not required for elastic fiber formation within fibrin. Collagen did not support substantial elastogenesis by SMC. The quantity of crosslinked elastic fibers was enhanced by treatment with TGF-beta1 and insulin, concomitant with increased collagen production. These additives overcame ascorbate's inhibition of elastogenesis in fibrin. The elastic fibers that formed in fibrin treated with TGF-beta1 and insulin contained crosslinks, as evidenced by the presence of desmosine and an altered elastin labeling pattern when beta-aminopropionitrile (BAPN) was added. These findings indicate that in vitro elastogenesis can be achieved in tissue engineering applications, and they suggest a physiologically relevant model system for the study of three-dimensional elastic structures.
authors.affiliation: Department of Chemical Engineering & Materials Science and Department of Biomedical Engineering, 7-114 BSBE, 312 Church St SE, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Long
authors.forename: Robert T
authors.initials: RT
authors.lastname: Tranquillo
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D003094:Collagen / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D004548:Elasticity; D004549:Elastin / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D000071838:Fibrillin-1; D000071837:Fibrillins; D005337:Fibrin / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007328:Insulin / Q000494:pharmacology; D008840:Microfilament Proteins / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D023822:Tissue Engineering; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1; D054392:Adipokines
chemical_list: D000596:Amino Acids; D001205:Ascorbic Acid; D003094:Collagen; D004549:Elastin; D000071838:Fibrillin-1; D000071837:Fibrillins; D005337:Fibrin; D007328:Insulin; D008840:Microfilament Proteins; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C000605722:FBN1 protein, human; D054392:Adipokines; C000605725:Fbn1 protein, rat; C508960:TGFB1 protein, human; C508962:Tgfb1 protein, rat