Laser-modified titanium surfaces enhance the osteogenic differentiation of human mesenchymal stem cells

Stem Cell Res Ther. 2017 Nov 28;8(1):269. doi: 10.1186/s13287-017-0717-9.

Abstract

Background: Titanium surfaces have been modified by various approaches with the aim of improving the stimulation of osseointegration. Laser beam (Yb-YAG) treatment is a controllable and flexible approach to modifying surfaces. It creates a complex surface topography with micro and nano-scaled patterns, and an oxide layer that can improve the osseointegration of implants, increasing their usefulness as bone implant materials.

Methods: Laser beam irradiation at various fluences (132, 210, or 235 J/cm2) was used to treat commercially pure titanium discs to create complex surface topographies. The titanium discs were investigated by scanning electron microscopy, X-ray diffraction, and measurement of contact angles. The surface generated at a fluence of 235 J/cm2 was used in the biological assays. The behavior of mesenchymal stem cells from an umbilical cord vein was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, a mineralization assay, and an alkaline phosphatase activity assay and by carrying out a quantitative real-time polymerase chain reaction for osteogenic markers. CHO-k1 cells were also exposed to titanium discs in the MTT assay.

Results: The best titanium surface was that produced by laser beam irradiation at 235 J/cm2 fluence. Cell proliferation analysis revealed that the CHO-k1 and mesenchymal stem cells behaved differently. The laser-processed titanium surface increased the proliferation of CHO-k1 cells, reduced the proliferation of mesenchymal stem cells, upregulated the expression of the osteogenic markers, and enhanced alkaline phosphatase activity.

Conclusions: The laser-treated titanium surface modulated cellular behavior depending on the cell type, and stimulated osteogenic differentiation. This evidence supports the potential use of laser-processed titanium surfaces as bone implant materials, and their use in regenerative medicine could promote better outcomes.

Keywords: Biocompatibility; Human umbilical cord; Laser beam (Yb-YAG); Mesenchymal stem cells; Osteoinduction; Surface modification; Titanium.

MeSH terms

  • Alkaline Phosphatase / genetics
  • Alkaline Phosphatase / metabolism
  • Biomarkers / metabolism
  • Bone Morphogenetic Protein 2 / genetics
  • Bone Morphogenetic Protein 2 / metabolism
  • Cell Differentiation / drug effects*
  • Core Binding Factor Alpha 1 Subunit / genetics
  • Core Binding Factor Alpha 1 Subunit / metabolism
  • Gene Expression
  • Humans
  • Lasers
  • Mesenchymal Stem Cells / cytology
  • Mesenchymal Stem Cells / drug effects*
  • Mesenchymal Stem Cells / metabolism
  • Microscopy, Electron, Scanning
  • Osteoblasts / cytology
  • Osteoblasts / drug effects*
  • Osteoblasts / metabolism
  • Osteocalcin / genetics
  • Osteocalcin / metabolism
  • Osteogenesis / drug effects*
  • Osteogenesis / genetics
  • Osteopontin / genetics
  • Osteopontin / metabolism
  • Primary Cell Culture
  • Prostheses and Implants
  • Surface Properties
  • Titanium / pharmacology
  • Titanium / radiation effects*
  • Umbilical Cord / cytology
  • Umbilical Cord / drug effects
  • Umbilical Cord / metabolism

Substances

  • BMP2 protein, human
  • Biomarkers
  • Bone Morphogenetic Protein 2
  • Core Binding Factor Alpha 1 Subunit
  • RUNX2 protein, human
  • SPP1 protein, human
  • Osteocalcin
  • Osteopontin
  • Titanium
  • ALPL protein, human
  • Alkaline Phosphatase