A Newly Created Meso-, Micro-, and Nano-Scale Rough Titanium Surface Promotes Bone-Implant Integration

Abstract

Titanium implants are the standard therapeutic option when restoring missing teeth and reconstructing fractured and/or diseased bone. However, in the 30 years since the advent of micro-rough surfaces, titanium’s ability to integrate with bone has not improved significantly. We developed a method to create a unique titanium surface with distinct roughness features at meso-, micro-, and nano-scales. We sought to determine the biological ability of the surface and optimize it for better osseointegration. Commercially pure titanium was acid-etched with sulfuric acid at different temperatures (120, 130, 140, and 150 °C). Although only the typical micro-scale compartmental structure was formed during acid-etching at 120 and 130 °C, meso-scale spikes (20–50 μm wide) and nano-scale polymorphic structures as well as micro-scale compartmental structures formed exclusively at 140 and 150 °C. The average surface roughness (Ra) of the three-scale rough surface was 6–12 times greater than that with micro-roughness only, and did not compromise the initial attachment and spreading of osteoblasts despite its considerably increased surface roughness. The new surface promoted osteoblast differentiation and in vivo osseointegration significantly; regression analysis between osteoconductivity and surface variables revealed these effects were highly correlated with the size and density of meso-scale spikes. The overall strength of osseointegration was the greatest when the acid-etching was performed at 140 °C. Thus, we demonstrated that our meso-, micro-, and nano-scale rough titanium surface generates substantially increased osteoconductive and osseointegrative ability over the well-established micro-rough titanium surface. This novel surface is expected to be utilized in dental and various types of orthopedic surgical implants, as well as titanium-based bone engineering scaffolds.

UV-Photofunctionalization of Titanium Promotes Mechanical Anchorage in A Rat Osteoporosis Model

“…Initial attachment of cells was evaluated by measuring the number of cells attached to the titanium disks after 24 h of incubation in a WST-1-based colorimetric assay (WST-1, Roche Applied Science, Mannheim, Germany). As previously described [50], the amount of formazan product was measured with a multi-detection microplate reader, Synergy TM HT (BioTek Instruments, Winooski, VT, USA), at a wavelength of 450 nm. Additionally, the proliferative activity of the cells was measured by BrdU incorporation during DNA synthesis on day 5 of culture [51].…”

“…Spreading behavior and cytoskeletal arrangement of osteoblasts seeded onto the titanium surfaces were examined by confocal laser scanning microscopy (TCS SP5, Leica, Wetzlar, Germany), as previously described [50]. After 24 h of culture, osteoblasts were fixed and stained with fluorescent rhodamine phalloidin dye (actin filament, red color; R415, Molecular Probes, Eugene, OR, USA) and vinculin (green color; ab11194, Abcam, Cambridge, UK).…”

Laser Ablated Periodic Nanostructures on Titanium and Steel Implants Influence Adhesion and Osteogenic Differentiation of Mesenchymal Stem Cells

“…Especially for metal implants in load-bearing regions, osseointegration-induced stabilization and accelerated tissue integration are crucial. Hence, several surface modification strategies that improve osseointegration have been performed in the last decade [42][43][44][45]. Especially for metal implants in load-bearing regions, increased bone formation and accelerated tissue integration seem reasonable.…”

“…Nevertheless, several studies describe complications during nail removal through nail failure, jamming in the fracture callus during removal, or difficulties and need for special instruments [46][47][48]. Most studies of modified surfaces focused on increased cell adhesion/osseointegration [39,[42][43][44][45] or decreased bacteria adhesion/prevention of biofilm formation [49][50][51]. Nevertheless, Lavenus et al described limited effects of nanopore-modified titanium on the osteogenic differentiation of MSCs.…”

UV-Pre-Treated and Protein-Adsorbed Titanium Implants Exhibit Enhanced Osteoconductivity

“…The initial attachment of cells to the different titanium surfaces was performed using WST-1 reagent (Roche Applied Science, Basel, Switzerland) and observed using confocal laser scanning microscopy (CLSM) (TCS SP5, Leica, Wetzlar, Germany) after 24 h of incubation. Following a previously established protocol [ 36 ], the absorption value was measured in a spectrophotometer at 450 nm with a plate reader (Biotek). For CLSM (TCS SP5, Leica), the cells were fixed with 10% formalin and stained with rhodamine-phalloidin dye (actin filament, red color; R415, Molecular Probes, Eugene, OR, USA) and vinculin (green color; ab11194, Abcam, Cambridge, UK) [ 37 ].…”