CSIRO, PolyNovo extend orthopaedic collaboration

PolyNovo Biomaterials and the CSIRO have shaken hands on an agreement to extend their collaboration on a radical new method of repairing damaged cartilage in the knees and joints, using the CSIRO-developed biopolymer NovoSorb.

PolyNovo CEO Dr Ian Griffiths said the company was "greatly encouraged" by the significant progress being made in delivering live cells in NovoSorb.

The next phase will focus on specific aspects of delivery to the knee cartilage.

If the collaboration is successful, PolyNovo, CSIRO and the Industrial Research Institute of Taiwan will spin out a company to commercialise the technology.

PolyNovo is jointly owned by CSIRO and Xceed Biotechnology (ASX:XBL). In May this year, it formed a collaboration with CSIRO and ITRI to develop new cartilage-repair techniques, which Griffith said would will result in a paradigm shift in orthopaedic surgery if successful.

The technology incorporates cartilage-building chondrocytes with a small amount of nutrients in the porous, polyurethane-based, biocompatible and biodegradable polymer. The nutrient supply sustains the cells for 24-48 hours, time enough to secure a permanent nutrient and growth-factor supply within the local environment.

The polymer can be introduced into damaged joints as an injectable liquid or pliable putty, using minimally invasive keyhole surgery.

Knee-cartilage injuries feature almost weekly in media sports reports, but Griffiths said that, around the year, millions of people suffer debilitating cartilage injuries that cause significant pain and economic loss, and restrict people's lifestyles.

Ultimately, bone-on-bone contact due to loss of the cushioning cartilage results in osteoarthritis later in life. One current technique is to inject chondrocytes into the knee, but it can take months to build new cartilage, during which time the patient must use crutches to avoid placing pressure on the knee, which could crush and distort the new cartilage. The new cartilage also does not fuse with remaining cartilage in the knee, which can create stability problems when the patient resumes exercising.

Griffiths said the global market for PolyNovo products is estimated at US$2.5 billion a year. There are multiple potential applications, including using the polymer as a glue to rapidly repair bone fractures, and stabilising and repairing bone fractures that refuse to heal. The polymer can also be used to create biodegradable tubes -- stents -- to replace arteries and other body plumbing.

Griffiths said several big orthopaedics companies were very interested in the bone-repair technology.

He said CSIRO researchers have developed techniques for rapidly expanding chrondrocytes in vitro -- a small cartilage biopsy can be expanded into enough cells for an autograft in around a week.

In the case of knee-cartilage repair, Griffiths said exposure to ultraviolet light triggers rapid polymerisation, and the injected material becomes hard enough to take the patient's weight within about two hours.

There is no prolonged period of immobilisation, which can cause other health problems.

Griffiths said the next stage of the collaboration would be to verify that the keyhole surgery approach works in animal models, and to submit to Australia's Therapeutic Goods Administration that the technology is safe.

"The whole process should take about 24 to 30 months, and then we can think about a pilot study in human volunteers," he said.

He said the proposed spinout company will take the technology as far as it can with its own resources, to maximise its value. "Given the dynamics of the industry, and the sheer might required to introduce a revolutionary technology, we are extremely likely to take a partner," he said.