title: Titanium surface topography affects collagen biosynthesis of adherent cells.
abstract: Collagen-dependent microstructure and physicochemical properties of newly formed bone around implant surfaces represent key determinants of implant biomechanics. This study investigated the effects of implant surface topography on collagen biosynthesis of adherent human mesenchymal stem cells (hMSCs). hMSCs were grown for 0 to 42 days on titanium disks (20.0 × 1.0 mm) with smooth or rough surfaces. Cell attachment and spreading were evaluated by incubating cells with Texas-Red-conjugated phalloidin antibody. Quantitative real-time PCR was used to measure the mRNA levels of Col1α1 and collagen modifying genes including prolyl hydroxylases (PHs), lysyl oxidases (LOXs) and lysyl hydroxylases (LHs). Osteogenesis was assessed at the level of osteoblast specific gene expression and alizarin red staining for mineralization. Cell layer-associated matrix and collagen content were determined by amino acid analysis. At 4h, 100% cells were flattened on both surfaces, however the cells on smooth surface had a fibroblast-like shape, while cells on rough surface lacked any defined long axis. PH, LH, and most LOX mRNA levels were greater in hMSCs grown on rough surfaces for 3 days. The mineralized area was greater for rough surface at 28 and 42 days. The collagen content (percent total protein) was also greater at rough surface compared to smooth surface at 28 (36% versus 26%) and 42 days (46% versus 29%), respectively (p<.05). In a cell culture model, rough surface topography positively modulates collagen biosynthesis and accumulation and the expression of genes associated with collagen cross-linking in adherent hMSC. The altered biosynthesis of the collagen-rich ECM adjacent to endosseous implants may influence the biomechanical properties of osseointegrated endosseous implants.
authors.affiliation: Bone Biology and Implant Therapy Laboratory, Department of Prosthodontics, University of North Carolina at Chapel Hill, 330 Brauer Hall, CB #7450, Chapel Hill, NC 27599, USA. daniela_mendonca@dentistry.unc.edu
authors.forename: Daniela B S
authors.initials: DB
authors.lastname: Mendonça
authors.forename: Patrícia A
authors.initials: PA
authors.lastname: Miguez
authors.forename: Gustavo
authors.initials: G
authors.lastname: Mendonça
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Yamauchi
authors.forename: Francisco J L
authors.initials: FJ
authors.lastname: Aragão
authors.forename: Lyndon F
authors.initials: LF
authors.lastname: Cooper
mesh_terms: D058578:Biglycan / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis* / Q000235:genetics; D049030:Dystroglycans / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000737:chemistry; D050958:HSP47 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D008240:Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase / Q000235:genetics / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D008249:Protein-Lysine 6-Oxidase / Q000235:genetics / Q000378:metabolism; D013499:Surface Properties; D019714:Tissue Inhibitor of Metalloproteinases / Q000235:genetics / Q000378:metabolism; D014025:Titanium / Q000737:chemistry*; D053773:Transforming Growth Factor beta1 / Q000235:genetics / Q000378:metabolism
chemical_list: D058578:Biglycan; D024042:Collagen Type I; D050958:HSP47 Heat-Shock Proteins; D020033:Protein Isoforms; D019714:Tissue Inhibitor of Metalloproteinases; D053773:Transforming Growth Factor beta1; D049030:Dystroglycans; D014025:Titanium; D011393:Procollagen-Proline Dioxygenase; D008240:Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase; D008249:Protein-Lysine 6-Oxidase; D020782:Matrix Metalloproteinases