Although known to reduce inflammation and aid in the repair of damaged tissue, the protein molecule called C-type natriuretic peptide (CNP) could not previously be put to use in treating osteoarthritis as it breaks down easily in the body. But now researchers at Queen Mary University of London (QMUL) could make this possible by using slow-release microcapsules containing the protein.

CNP, which occurs naturally in the body, being produced by the endothelium and the heart, is believed to play a major role in vascular and cardiac function. Although it reduces inflammation and aids in the repair of damaged tissue, it could not perform these functions in the treatment of osteoarthritis, even if injected into the cartilage tissue, because it breaks down before it can reach the site of the damage.

To overcome this, Dr Tina Chowdhury from QMUL's School of Engineering and Materials Science led a team that created microcapsules containing CNP. Measuring just 2 microns in diameter, these microcapsules were made up of individual layers containing CNP, which allows the protein to be delivered to and released slowly at the relevant location.

The team has already tested the microcapsules on samples of animal cartilage with positive results, which bodes well for potential use in healing damaged cartilage of human osteoarthritis sufferers. The researchers say that in the future, the microcapsules could be delivered via injections given by a local GP.

"If this method can be transferred to patients it could drastically slow the progression of osteoarthritis and even begin to repair damaged tissue," said Dr Chowdhury. "CNP is currently available to treat other conditions such as skeletal diseases and cardiovascular repair. If we could design simple injections using the microcapsules, this means the technology has the potential to be an effective and relatively cheap treatment that could be delivered in the clinic or at home."

The team's research was funded by Arthritis Research UK and the AO Foundation.

Source: QMUL