title: Proliferation of preosteoblasts on TiO2nanotubes is FAK/RhoA related.
abstract: Topographies promote surface-dependent behaviors which may positively influence peri-implant bone healing. In this study the topological effects of TiO2nanotubes (TNTs) on aspects of preosteoblast behavior was investigated. Specifically, we hypothesize that TNTs can influence cell proliferation of preosteoblasts through cell adhesion and related modulation of FAK and RhoA. By culturing MC3T3-E1 cells on TNTs with different diameters (40nm and 150nm diameters), topography-dependent modulation in cell morphology and cell growth were observed. The average spreading area of the cell on Flat Ti, 40nm TNTs and 150nm TNTs were respectively 2176.05 μm2, 1510.44 μm2and 800.72 μm2. Proliferation increased among cells cultured on the 150nm TNTs (28.6%) compared with on Flat Ti (17.06%). The expression of FAK was 86.2% down regulated superimposition of TNTs topography. RhoA expression only slightly decreased (45.9%). Increasing TNT diameter enhanced initial adherent cell growth, which was relevant to the increased RhoA-to-FAK ratio in the cell. Increased TNT diameter was associated with higher ratio and greater proliferation in the first 24 hours. These findings not only support our hypothesis, but suggest that RhoA might be critically involved in TNTs mediated cell proliferation. Future investigation using functional gain and loss of RhoA may further reveal its mechanism.
authors.affiliation: Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Hi gher Education, College of Stomatology, Chongqing Medical University, Chongqing 401147, China.
authors.forename: He
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Hi gher Education, College of Stomatology, Chongqing Medical University, Chongqing 401147, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: Division of Bioprosthodontics, Department of Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8514, Japan ; NC Oral Health Institute, School of Dentistry, University of North Carolina, CB #7454, Chapel Hill, NC 27599, USA.
authors.forename: Nagasawa
authors.initials: N
authors.lastname: Masako
authors.affiliation: NC Oral Health Institute, School of Dentistry, University of North Carolina, CB #7454, Chapel Hill, NC 27599, USA.
authors.forename: Dong Joon
authors.initials: DJ
authors.lastname: Lee
authors.affiliation: NC Oral Health Institute, School of Dentistry, University of North Carolina, CB #7454, Chapel Hill, NC 27599, USA ; Department of Prosthodontics, School of Dentistry, University of North Carolina, CB #7450, Chapel Hill, NC 27599-7450, USA.
authors.forename: Lyndon F
authors.initials: LF
authors.lastname: Cooper
authors.affiliation: NC Oral Health Institute, School of Dentistry, University of North Carolina, CB #7454, Chapel Hill, NC 27599, USA ; Department of Orthodontics, School of Dentistry, University of North Carolina, CB #7450, Chapel Hill, NC 27599-7450, USA.
authors.forename: Ching-Chang
authors.initials: CC
authors.lastname: Ko