Titanium nano-nodular structuring for osseointegration

Objectives: Nanostructuring technologies have proven to create unique properties of various materials, which explores next generation of the existing micron-scale technologies. Development of nano-level roughness may provide approaches to enhance the interfacial strength between the biomaterials and overlaying biological tissues. This study examined the potential of newly-developed nano-nodular structuring of titanium dioxide (TiO2) to enhance its tissue integration capacity.

Methods: Titanium disks, etched with hydrofluoric acid and sulfuric acid, were deposited with titanium dioxide using sputter coating technique for various time period. Morphology and profile of the surfaces was examined qualitatively by scanning electron microscopy and quantitatively by atomic force microscopy. Also, the morphology of the TiO2-depositioned surface was compared with that of the cultured mineralized matrix by rat bone marrow-derived osteoblasts. To imply the biomechanical potential of TiO2 surface for bone integration, bonding capacity of the created surfaces with acrylic resin was tested using a tensile test.

Results: SEM images showed that TiO2 sputter deposition onto the acid-etched results in the self-assembly of unique, dendritic, nano-nodular structure of TiO2. The diameter and height of the nano-nodules were controllable by varying the deposition time, and depending on the deposition time, nano-micro-hybrid architectures were created. The surface area increased by the nano-nodular structuring by up to 40% compared to the acid-etched surface with microtopography (ANOVA, p<0.01). Titanium-resin bonding strength increased by nano-nodules (p<0.01), with 300 nm nano-nodules showing 2.5 times greater strength than the acid-etched surface. The TiO2 nano-nodular surface surprisingly resembled nano-scale globular calcium-binding proteins on cultured mineralized matrix.

Conclusion: These results have provided a new avenue in creating unique TiO2 nano-nodular surface and micro-and-nano-hybrid topography of titanium. The surface has been demonstrated to mimic biological structures of bone and generate an enhanced capacity for interfacial bonding, which compellingly suggests an immediate exploration of this surface for biological osseointegration capacity.