title: Comparison of human fibroblast ECM-related gene expression on elastic three-dimensional substrates relative to two-dimensional films of the same material.
abstract: Three-dimensional elastic substrates were fabricated from a commercially available polyurethane with an internal porosity of approximately 70% and elastic modulus of 27.4+/-2.76 KPa and examined for suitability in vocal fold tissue engineering. Using immunohistochemistry, biomechanical testing, and RT-PCR; we examined human fibroblast viability, distribution and extracellular matrix related gene expression within substrates for periods up to 4 weeks. We found that cells were capable of colonizing the entire volume of a 5mm wide x 3mm deep x 20mm long substrate at high viability. Histological cross-sections showed extensive extracellular matrix deposited around the cells and throughout the pore structure of the substrates, which consisted of fibronectin and type I collagen. Cell seeded substrates displayed a significantly higher elastic modulus than unseeded controls similar to native tissue. The transfer of cell growth from two-dimensional to three-dimensional culture resulted in changes in ECM-related gene expression consistent with decreasing cell migration and increasing tissue formation. We found that fibroblasts cultured in three-dimensional substrates expressed significantly higher levels of mRNA for elastin and fibromodulin, while expressing significantly lower levels of mRNA for MMP-1 and hyaluronidase relative to two-dimensional substrates of the same material. The results suggest that three-dimensionally porous, Tecoflex-derived elastic biomaterials may be suitable substrates for engineering vocal fold tissue.
authors.affiliation: The Keck Center for Tissue Engineering, Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Webb
authors.forename: Wenhua
authors.initials: W
authors.lastname: Li
authors.forename: Robert W
authors.initials: RW
authors.lastname: Hitchcock
authors.forename: Roy M
authors.initials: RM
authors.lastname: Smeal
authors.forename: Steven D
authors.initials: SD
authors.lastname: Gray
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Tresco
mesh_terms: D000199:Actins / Q000378:metabolism; D000328:Adult; D001672:Biocompatible Materials / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D004548:Elasticity; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008297:Male; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014132:Trachea / Q000166:cytology; D014827:Vocal Cords / Q000033:anatomy & histology
chemical_list: D000199:Actins; D001672:Biocompatible Materials; D011108:Polymers