Better method of bone regeneration

Biomedical engineers from the University of Glasgow have used a cheap, commercially produced polymer to assist in bone regeneration, which could result in better therapies for spinal injuries, bone grafts and other orthopaedic surgeries.

Writing in the journal Scientific Advances, the scientists explain that the polymer poly(ethyl acrylate) helps stimulate growth factors — molecules which help the body to regenerate. Growth factors play an important role in developmental biology, orchestrating development as bodies grow and age.

A growth factor molecule known as bone morphogenetic protein 2 (BMP-2) has already been used for several years in clinical applications to help encourage bone regrowth in patients. However, wider adoption of BMP-2 techniques has been limited by the human body’s tendency to pass the protein quickly through its system. To get around it, clinicians need to use BMP-2 in large doses, which can cause harmful side effects such as neurological impairment or even tumours.

The researchers utilised a unique property of poly(ethyl acrylate) to allow growth factors to be effective at doses around 300 times lower than currently possible. Lower doses lower the risk of harmful side effects and reduce the potential cost of treatment.

“The polymer facilitates a reaction with fibronectin, a protein which binds growth factors to allow the body to regenerate,” explained Professor Matthew Dalby, a co-author on the study. “In the body, in tissues, fibronectin is opened up by cells to allow growth factors to attach and allow regeneration to begin. In the BMP-2 therapy currently in use, growth factor uptake is limited because they are not presented in a biomimetic way but rather delivered in soluble form in high quantities. Our polymer helps fibronectin act as it does normally within the body.”

According to co-author Professor Manuel Salmeron-Sanchez, the technique “opens up the possibility of making growth factor treatments much more effective and much more affordable”.

“By coating materials such as hip implants, bone grafts or spinal cages in a thin layer of this polymer, we can encourage bone regeneration targeted on the areas where they’re required,” he said.

The research was funded by the European Research Council, the UK Medical Research Council and the Marie Curie International Outgoing Fellowship program. The researchers are currently in the process of securing additional funding to further explore their findings, with the hope that the first human trial could be underway in the next five years.

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