Role of integrin subunits in mesenchymal stem cell differentiation and osteoblast maturation on graphitic carbon-coated microstructured surfaces
Por:
Olivares-Navarrete R., Rodil S.E., Hyzy S.L., Dunn G.R., Almaguer-Flores A., Schwartz Z., Boyan B.D.
Publicada:
1 may 2015
Resumen:
Surface roughness, topography, chemistry, and energy promote osteoblast differentiation and increase osteogenic local factor production invitro and bone-to-implant contact invivo, but the mechanisms involved are not well understood. Knockdown of integrin heterodimer alpha2beta1 (a2ß1) blocks the osteogenic effects of the surface, suggesting signaling by this integrin homodimer is required. The purpose of the present study was to separate effects of surface chemistry and surface structure on integrin expression by coating smooth or rough titanium (Ti) substrates with graphitic carbon, retaining surface morphology but altering surface chemistry. Ti surfaces (smooth [Ra<0.4µm], rough [Ra=3.4µm]) were sputter-coated using a magnetron sputtering system with an ultrapure graphite target, producing a graphitic carbon thin film. Human mesenchymal stem cells and MG63 osteoblast-like cells had higher mRNA for integrin subunits a1, a2, av, and ß1 on rough surfaces in comparison to smooth, and integrin av on graphitic-carbon-coated rough surfaces in comparison to Ti. Osteogenic differentiation was greater on rough surfaces in comparison to smooth, regardless of chemistry. Silencing integrins ß1, a1, or a2 decreased osteoblast maturation on rough surfaces independent of surface chemistry. Silencing integrin av decreased maturation only on graphitic carbon-coated surfaces, not on Ti. These results suggest a major role of the integrin ß1 subunit in roughness recognition, and that integrin alpha subunits play a major role in surface chemistry recognition. © 2015 Elsevier Ltd.
Filiaciones:
Olivares-Navarrete R.:
Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, United States
Rodil S.E.:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Mexico City 04510, DF, Mexico
Hyzy S.L.:
Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, United States
Dunn G.R.:
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
Almaguer-Flores A.:
Univ Nacl Autonoma Mexico, Fac Odontol, Mexico City 04510, DF, Mexico
Schwartz Z.:
Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, United States
Boyan B.D.:
Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, United States
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
|