ETH-Zurich to license bone regeneration wool, gas sensor

Two Licensing Opportunities

Scientists at the Swiss Federal Institute of Technology Zurich (ETH-Zurich) have developed two new inventions which are now available for licensing.  The first is a bone regeneration material called Bone Cotton Wool which is particularly effective in dental applications, and the second is a gas sensor device using photoacoustic technology, converting light energy into acoustic waves, to identify gases in foods and the environment.

It has been shown that the combination of both a ceramic and a polymer within one material results in composites, which have the ductility of a polymer and the bioactivity of the calcium phosphate phase.

The invention of Bone Cotton Wool relates to the preparation of a new and advanced implant material consisting of a biodegradable polymer such as PLGA with up to 40% of amorphous tricalcium phosphate (ATCP) nanoparticles incorporated into the polymer. These ATCP nanoparticles can be solely prepared by a dry, one step preparation method called flame spray synthesis (IP is covered by ETH Zurich, WO2005/ 087660).

The new composite is prepared by electrospinning, a technique which produces open structured, ultrafine fibers. The resulting Bone Cotton Wool is very flexible and easy to shape due to its cotton wool-like appearance. The high reactivity of the ATCP nanoparticles within the new implant material gave rise to most promising results on in vitro biomineralization. Currently the new implant material is tested in vivo in an animal model.

• Improved bioactivity compared to current materials
• Apatite deposition after 48 hours
• Easy to apply: flexible, elastic, and compressible
• Bone Cotton Wool is removable if misplaced
• Fully synthetic material

Field of Application

• Bone regeneration, especially in dental applications such as: Sinus lift, periodontal regeneration, socket preservation
• Other non-load bearing indications in orthopedic surgery

Patent status

• Patent pending PCT

Background

Given the world’s demographic shift towards an older population and today’s lifestyles involving increasing sports activities, an inevitable rise in orthopedic injuries and diseases is expected.

Today, most of the surgical operations to repair fractures and bone defects are performed using autografts and allografts despite their limitations in terms of availability, donor-site morbidity, and potentially negative immune responses. This has triggered research to find fully synthetic alternative bone substitute materials. Ceramics such as hydroxyapatite and tricalcium phosphate, but also biodegradable polymers such as poly(lacticco- glycolic) acid (PLGA) are increasingly used in bone repair and regeneration creating a growing market for such synthetic implants. However, current materials have their limitations, such as brittleness, being difficult to shape or having constricted bioactivity.

Ref. No. T-06-059

The invention relies on the fact that two spatially separated beams passing through a target gas located in a resonant photoacoustic cell will differently excite two different acoustic modes of the cell. In this novel method the photoacoustic amplitudes of the two acoustic modes are monitored. The amplitude ratio of the two modes is a measure of the relative intensities of the two light beams reaching the photoacoustic cell.

In operation both beams enter the photoacoustic cell. This leads to a mode amplitude ratio that depends on the intensity ratio of the beams reaching the photoacoustic cell. Placing a sample cell into one of the beams in front of the photoacoustic cell yields a mode amplitude ratio that depends on the absorption in this sample cell. The concentration of the target gas can thus be derived without the need of an additional light power meter, as it is the case with previous photoacoustic gas sensors.

Main Advantages

• Simpler setup since no normalizing scheme (e.g. power-meter) is required
• Sensitive enough to operate with black-body light sources
• Reduced sensibility to microphone and electronics drifts
• Reduced photoacoustic frequency drifts
• Selective since based on the gas correlation technique
• Cost-effective

Field of Application

• Food and beverage monitoring
• Medical sensing
• Environmental health and safety
• Industrial process monitoring
• Chemical or forensic analysis
• Other

Patent Status

• Patent pending EP

Background

Photoacoustic gas sensors are well-established sensing devices thanks to their high sensitivity, large dynamic range and comparatively simple experimental set-up.

The photoacoustic effect consists in the conversion of absorbed light energy into acoustical waves which can be detected with microphones. In most known photoacoustic sensing schemes the absolute values of the microphone signal are measured and used to derive the concentration of the gas of interest. Since photoacoustic signals depend on the intensity of the excitation light source used, intensity normalisation schemes (power meter or reference cells) are required for quantitative measurements.

Ref. No. T-04-093