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

Abstract

BackgroundTitanium 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.MethodsLaser 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.ResultsThe 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.ConclusionsThe 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.

Surface characteristics on commercial dental implants differentially activate macrophages in vitro and in vivo

“…The final desired outcome of all bone‐implanted biomaterial is the de novo bone formation connecting the implant to the host bone, termed osseointegration, and the majority of the efforts to develop and test new dental implant modifications rely on tests using osteoblasts or MSCs to predict the implant outcome (Bressel et al, 2017; Fu et al., 2009; Jiang et al., 2015; Lotz et al., 2017; Zanicotti et al., 2018). While these types of tests are important to understand the behavior of bone‐forming cells in response to biomaterial modifications, they ignore the contribution of the other cellular and biological processes that occur in the peri‐implant environment in the 14–21 days before bone formation begins that also affect osseointegration and ultimately dictate the fate of the implanted biomaterial (Biguetti et al., 2018; Vlahović et al., 2017).…”

Customizable, engineered substrates for rapid screening of cellular cues

“…Manipulation of the cell micro-environment using biochemical and biophysical cues is therefore widely explored as a means to alter cell behavior both in vitro and in vivo [ 5 – 8 ]. Of particular interest are engineered substrates precisely and reproducibly made with defined biophysical properties [ 9 – 11 ]. Substrates that recapitulate substrate rigidity or surface topographical cues present in the cell environment have been shown in vitro to force cells to behave differently [ 12 – 14 ].…”

Approaches to promoting bone marrow mesenchymal stem cell osteogenesis on orthopedic implant surface

“…Laser beam treatment is a controllable and flexible approach to modifying surfaces, which results in surfaces with increased surface area and enhanced wettability, and it displays negligible corrosion and high removal torques of established implants in preclinical bone models[ 64 , 65 ]. Laser-modified titanium surfaces could enhance upregulation of expression of the osteogenic markers and enhance alkaline phosphatase activity of BMSCs[ 66 ]. A recent investigation on the direct metal laser sintering (DMLS) titanium surface found that topographical cues of DMLS surfaces could enhance both protein adsorption ability and BMSC adhesion performance.…”