Modified Titanium Surfaces Alter Osteogenic Differentiation: A Comparative Microarray-Based Analysis of Human Mesenchymal Cell Response to Commercial Titanium Surfaces
The differential effects of dual-acid etched (Osseotite), hydroxyapatite coated (HA) and sand-blasted/acid-etched (SLA) titanium surfaces on human bone marrow-derived mesenchymal cells (hMSCs) were investigated. Proliferation was significantly promoted on the SLA surfaces. 16 genes were significantly upregulated when hMSCs were cultured on the Osseotite and the HA surfaces and 15 genes on the SLA surfaces. Upregulated genes control cell differentiation, signal transduction, cell cycle regulation, angiogenesis, cell adhesion, and extracellular matrix and bone formation.
Figure 1. OSSEOTITE implant surface provoked a significantly increased in cell attachment compared to control (smooth surface-SMO) (P < .001). Attachment was significantly reduced when cells were grown on the SLA and the HA surfaces compared to control (P < .001). HA surface provoked the weakest initial hMSC attachment compared to all surfaces (P < .001). Figure 2. At Day 1 of the experiment, the SLA surface demonstrated a clear and statistically significant increase (P < .001) in hMSC cell proliferation as compared to both control and other implant surfaces. Figure 3. At Day 3, cell proliferation was found to be increased on both the SLA and the HA surface in a statistically significant manner (P < .001) when compared to the SMO surface. Cell proliferation was also found increased when cells were seeded on the OSSEOTITE implant surface as compared to control but not significantly (P = .137). Similarly to Day 1, the SLA surface demonstrated a statistically significant increase (P < .001) in hMSC cell proliferation as compared to both control and other implant surfaces. Figure 4. At Day 7, hMSC were found to proliferate on all tested surfaces in a statistically significant higher rate when compared to the control (P < .001). Again, the SLA surface demonstrated a statistically significant increase (P < .001) in proliferation as compared to both control and tested surfaces.