title: Human mesenchymal stem cell behavior on femtosecond laser-textured Ti-6Al-4V surfaces.
abstract: OBJECTIVE
  The aim of the present work was to investigate ultrafast laser surface texturing as a surface treatment of Ti-6Al-4V alloy dental and orthopedic implants to improve osteoblastic commitment of human mesenchymal stem cells (hMSCs).
  
  
  METHODS
  Surface texturing was carried out by direct writing with an Yb:KYW chirped-pulse regenerative amplification laser system with a central wavelength of 1030 nm and a pulse duration of 500 fs. The surface topography and chemical composition were investigated by scanning electron microscopy and x-ray photoelectron spectroscopy, respectively. Three types of surface textures with potential interest to improve implant osseointegration can be produced by this method: laser-induced periodic surface structures (LIPSSs); nanopillars (NPs); and microcolumns covered with LIPSSs, forming a bimodal roughness distribution. The potential of the laser treatment in improving hMSC differentiation was assessed by in vitro study of hMSCs spreading, adhesion, elongation and differentiation using epifluorescence microscopy at different times after cell seeding, after specific stainings and immunostainings.
  
  
  RESULTS
  Cell area and focal adhesion area were lower on the laser-textured surfaces than on a polished reference surface. Obviously, the laser-textured surfaces have an impact on cell shape. Osteoblastic commitment was observed independently of the surface topography after 2 weeks of cell seeding. When the cells were cultured (after 4 weeks of seeding) in osteogenic medium, LIPSS- and NP- textured surfaces enhanced matrix mineralization and bone-like nodule formation as compared with polished and microcolumn-textured surfaces.
  
  
  CONCLUSIONS
  The present work shows that surface nanotextures consisting of LIPSSs and NPs can, potentially, improve hMSC differentiation into an osteoblastic lineage.
authors: Instituto Superior Técnico-Universidade de Lisboa, CeFEMA-Centro de Física e Engenharia de Materiais Avançados, Av. Rovisco Pais, 1049 001 Lisbon, Portugal.
authors: Alexandre
authors: A
authors: Cunha
authors: Omar Farouk
authors: OF
authors: Zouani
authors: Laurent
authors: L
authors: Plawinski
authors: Ana Maria
authors: AM
authors: Botelho do Rego
authors: Amélia
authors: A
authors: Almeida
authors: Rui
authors: R
authors: Vilar
authors: Marie-Christine
authors: MC
authors: Durrieu
mesh_terms: D000497:Alloys; D002448:Cell Adhesion; D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D053844:Lasers, Solid-State; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D050997:Nanomedicine; D016348:Osseointegration; D010006:Osteoblasts / Q000166:cytology; D010012:Osteogenesis; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D014025:Titanium
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium
keywords: cell adhesion; cell differentiation; cell spreading; femtosecond lasers; laser surface texturing; matrix mineralization; mesenchymal stem cells; titanium alloys