'Very encouraging' Glasgow study could repair bone health

They believe the discovery could support the development of new treatments to help people living with serious skeletal injuries or cancer patients who have lost bone to the disease to regrow bone tissue.

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Growth factors play an important role in developmental biology, helping to organise the development of bodies as they grow from infancy into adulthood.

They also help the body to heal after injuries, where they initiate a complex series of processes which knit tissues back together.

However, growth factor therapies can have serious side-effects when used to heal bones.

Active proteins need to be administered in high doses at the site of bone breaks or defects in order to be effective.

Uncontrolled release of these active growth factors at the site of bone implant can cause bone formation where it is unintended – a process known as ectopic bone formation.

The treatments can also cause other side effects like postoperative inflammation, which can have negative effects on patients’ health.

The Glasgow University team led a study which experimented instead with an inexpensive polymer called poly(ethyl acrylate), or PEA, to develop a surgical implant which can be used at the site of a bone defect.

The unique properties of the implant’s surface allowed the team to capture the body’s inactive growth factors and ensure they start working only at the target site.

Small plastic tubes were coated with PEA in addition to two other substances - fibronectin, a protein found in the human body which helps cells stick together, and a growth factor protein, rLTBP1, which acts like a magnet for another type of molecule involved in regulating bone regeneration.

The implants were tested on mice (Image: Getty)

They demonstrated that these tubes - used as implants - were able to completely repair bone defects in mice.

The findings have been published in the journal, Advanced Materials.

Dr Udesh Dhawan, the lead author and a research fellow at Glasgow University's James Watt School of Engineering, said: “The biological processes that underpin this study have been understood for more than two decades, but this is the first time that they’ve been harnessed to produce this regenerative effect.

“Being able to deliver immobilised proteins directly to the treatment site in this way provides much more control over how growth factors become active and start the healing process.

"It also works at much lower concentrations than previous treatments, helping further minimise the chances of unwanted bone growth beyond the site in need of healing.”

The team’s findings build on years of advanced bone regeneration research spearheaded by the university.

Eva the dog's leg was saved in 2017 following an intervention at Glasgow University's Small Animal Hospital after she was hit by a car (Image: PA)

In 2017, a landmark treatment developed by Professor Manuel-Salmeron-Sanchez and Professor Matthew Dalby saved a badly injured dog’s leg from amputation.

In that case, the team harnessed the growth factor potential of a protein called BMP-2 bonded to a PEA surface to regrow bone in the dog’s leg.

Professor Salmeron-Sanchez, co-director of the university's Centre for the Cellular Microenvironment, said: “Growth factors are very powerful tools for helping the body heal, but currently they need to be very carefully applied to prevent negative side effects cancelling out any positive therapeutic benefits.

"Our approach to controlling the activation of growth factors could create new opportunities for patients in the future.

"It could help regrow bone for patients who have lost large sections to diseases like cancer or through serious accidents, providing a much higher quality of life for them.”

Dr Dhawan added: “This is a new step in the right direction, but physiological systems are more interconnected than we can imagine and how this new strategy affects other crucial components of the body such as immune cells still needs to be evaluated.

"Nevertheless, these are very encouraging results, which suggest that this new treatment could have real benefits in clinical settings to encourage bone regeneration.”