Your Nano Implant Questions Answered

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What benefits do nanotube surfaces have compared to other implant surfaces?

Increased Hydrophilicity: Many studies have shown that hydrophilic surfaces enhance the way bone cells attach to implants. The Nanovation nanotube surface treatment converts the slightly hydrophilic titanium implant surface to a super-hydrophilic surface, which measurably accelerates bone cell attachment activities.

This increase in the hydrophilic properties of the surface is measured by the reduction of the water droplet contact angle from 54° for untreated titanium to less than 4° for the Nanovation nanotube surface. This allows cells drawn to the nanotube array surface to flatten and spread out on the surface.

Improved Surface Morphology: Adding billions of nanotubes per square centimeter of implant surface substantially increases the surface area of the implant interacting with the surrounding bone cells. This is significantly more surface area compared to other processes that form structures that modify the implant surface only at the macro and micro levels.

The unique geometry of the nanotubular arrays presents billions of nanotube edges on a typical implant, resulting in a charge distribution that has been shown to be beneficial to cell adhesion in vitro. Additionally, the UCSD research has shown that the diameter of the nanotubes can be tuned to enhance the proliferation of different cell types.

Increased Osseointegration: Nanotube array surfaces enhance osseointegration, signal local stem cells to adhere, increase cell differentiation to osteoblast cells, and induce these osteoblast cells to incorporate into the implant surface.

These properties have all been well documented by thirty-two journal papers published in international journals from Professor Sungho Jin’s group at UC San Diego (the inventors of the TiO2 nanotube biomaterials) over the past decade. During this time, five PhD students successfully completed their thesis work on TiO2 nanotube biomaterials, and two post-doctorates also conducted active research on the subject.

Nanotubes encourage early cell attachment. Bone formation is shown by assays for calcium and phosphorus deposition. Genetic up-regulation for osteoblast cells occurs. The end result is early, comprehensive cell growth and attachment, resulting in substantially better values for in vitro implant adhesion pull-out tests, which are an accepted proxy test for osseointegration. The Nanovation nanotube surface results in a nine (9) times stronger bone adhesion compared to the same roughened titanium surface without nanotubes.

Improved Antimicrobial Properties: Nanotubes, and nanotubes enhanced by nano-silver particles, have been shown to have improved antimicrobial properties compared to non-treated surfaces. These in vitro studies appear in multiple peer-reviewed publications authored by researchers worldwide.

These studies, conducted by researchers not affiliated with Nanovation, have confirmed Professor Sungho Jin’s UCSD Lab reports that TiO2 nanotubes enhance antimicrobial properties, and Professor Amit Bandyopadhyay’s Washington State University lab findings that silver nanoparticles on TiO2 nanotubes further enhance antimicrobial properties. This intellectual property from both Professor Jin’s lab and Professor Bandyopadhyay’s lab has been licensed by Nanovation.

Are nanotubes truly an engineered nanotechnology with defined nano features?

Yes, nanotubes created with the Nanovation surface treatment are an engineered nanotechnology, resulting in billions of nanotubes approximately 80–100 nanometers in diameter with a wall thickness of about 10 nanometers on the surface of a typical implant. This is so small that tens of thousands of nanotubes collectively interact with the outside membrane of a single cell wall, touching the implant surface.

It’s true that all physical objects have a surface at the nano level. However, merely taking a SEM image of the randomly formed nano-morphology of an implant surface and implying that there is a correlation with a slight improvement in bone attachment is not equivalent to engineering a structure that has predetermined nano features and results in known bone attachment benefits.

Creating a predetermined physical structure at the nano level (between approximately 1 and 100 nanometers) is required if one is to characterize those features as a “nanotechnology.” The Nanovation nanotube technology is clearly defined at the nano level, is unique and purposeful, and has a quantified impact on cell behavior when the dimensions of the wall thickness, diameter, and height are modified.

Researchers worldwide are discovering that the shape and size of titanium oxide nanostructures are important for cell attachment and for the surface chemistry needed to repel unwanted microbes. Different structures, such as nano-pitting on a similar scale, or nanotubes that are smaller or larger than the Nanovation nanotubes, are not as effective as the Nanovation nanotubes at increasing osseointegration or providing an antimicrobial barrier.

Even if the titanium oxide chemistry is similar and the nanostructure appears to increase surface area or hydrophilicity similarly, the details of structure shape and scale still need to be characterized to draw meaningful comparisons.

What are some of the differences between nanotubes and hydroxyapatite coatings?

Nanotubes Are More Durable than HA Coatings: Unlike coatings, nanotubes are formed on the surface of the metal to avoid the flaking issues seen with HA coatings. The stress level at the interface of a coating usually increases with coating thickness.

Nanovation nanotubes are not a coating but are formed into the titanium oxide layer, only about 300–500 nm thick. Most HA coatings are thousands of times thicker and are therefore more prone to delamination and flaking.

With HA coatings, the short-term weak link is the bond between the titanium oxide and the HA coating, and the long-term weak link (as hydroxyapatite degrades and is absorbed) is the bond between the smooth TiO2 surface and the bone cells. Consequently, HA coatings are more prone to flaking compared to the bonding between nanotubes and bone cells.

Nanotubes Have No Added Chemistry: Unlike HA coatings or polymer coatings, no synthetic organic or inorganic degradable materials are added to the implant. TiO2 nanotubes are made by anodization through simultaneous build-up and etching of the titanium oxide layer.

The process does not add additional synthetic inorganic materials, such as the calcium apatite and phosphate minerals associated with synthetic hydroxyapatites. The process also does not disrupt the titanium underneath the TiO2 but instead enhances the TiO2 barrier.

How much will it cost to put nanotubes on our product?

Will the cost change with time?

What kind of marketing support can my company expect to receive from Nanovation?

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