title: Establishing a gingival fibroblast phenotype in a perfused degradable polyurethane scaffold: mediation by TGF-β1, FGF-2, β1-integrin, and focal adhesion kinase.
abstract: Medium perfusion has been shown to enhance cell proliferation and matrix protein production. In more recent work, under perfusion, a degradable/polar/hydrophobic/ionic polyurethane (D-PHI) scaffold was shown to enhance growth and production of collagen by human gingival fibroblasts (HGFs). However, the nature of the HGFs cultured in the perfused D-PHI scaffolds, and the mechanisms by which medium perfusion activates these cells to facilitate proliferation and collagen production are not defined. The current study sought to investigate HGF interaction within the D-PHI scaffolds under perfusion by examining the production and the spatial distribution of α-smooth muscle actin (α-SMA) and type I collagen (Col I), the secretion of transforming growth factor (TGF)-β1 and basic fibroblast growth factor (FGF-2) in the conditioned medium, with a goal of defining the mechanistic pathways affecting the production of these markers in the dynamic culture. It was found that the perfused D-PHI scaffold shifted the HGF phenotype from myofibroblast-like (upregulation of α-SMA) to fibroblast-like (downregulation of α-SMA) over the course of 28 days. Both TGF-β1 and FGF-2 were significantly greater in the dynamic vs. static culture at day 1. Although TGF-β1 has been often reported to increase α-SMA and collagen expression, the D-PHI material and significant high level of FGF-2 at day 1 of dynamic culture appear to play a role in regulating α-SMA production while allowing HGFs to increase Col I production. β1-integrin production was increased and focal adhesion kinase (FAK) were activated 2 h after HGFs were exposed to medium perfusion, which may have in part promoted cell growth, α-SMA and Col I production in the early dynamic culture. Consequently, the D-PHI material and medium perfusion has modulated fibroblast phenotype, and enhanced cell growth and Col I production through the coordinated actions of TGF-β1, FGF-2, β1-integrin and FAK.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 124 Edward Street, Room 461, Toronto, Ontario M5G 1G6, Canada. Electronic address: jane.cheung@utoronto.ca.
authors.forename: Jane W C
authors.initials: JW
authors.lastname: Cheung
authors.affiliation: Matrix Dynamics Group, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario M5G 1G6, Canada.
authors.forename: Christopher A G
authors.initials: CA
authors.lastname: McCulloch
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 124 Edward Street, Room 461, Toronto, Ontario M5G 1G6, Canada; Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, Ontario M5G 1G6, Canada. Electronic address: paul.santerre@utoronto.ca.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Santerre
mesh_terms: D020341:Absorbable Implants; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D002470:Cell Survival / Q000502:physiology; D019544:Equipment Failure Analysis; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D016557:Guided Tissue Regeneration, Periodontal / Q000295:instrumentation*; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism; D010477:Perfusion / Q000295:instrumentation; D011140:Polyurethanes / Q000737:chemistry*; D011474:Prosthesis Design; D054457:Tissue Scaffolds; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; D019012:Integrin beta1; D011140:Polyurethanes; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2; D051416:Focal Adhesion Protein-Tyrosine Kinases
keywords: Bioreactor; Collagen; Connective tissue; Fibroblasts; Polyurethane; Soft tissue biomechanics