Plastic compound provides foundation for bone regeneration

8 February 2013

Edinburgh and Southampton Universities have developed a plastic compound with sponge-like pores that can replace damaged bone and allows the patient's own cells to grow into and take over the material.

The structure allows blood to flow through and has the right dimensions to enable stem cells from the patient’s bone marrow to attach to the material and grow new bone. Over time, the plastic slowly degrades as the implant is replaced by newly grown bone.

A team of chemists and bone scientists developed the material by blending three types of plastics. They used a pioneering technique to blend and test hundreds of combinations of plastics, to identify a blend that was robust, lightweight, and able to support bone stem cells. Successful results have been shown in the lab and in animal testing with the focus now moving towards human clinical evaluation.

Materials studied were a mixture of natural and synthetic polymers that have already been used in biomedical applications, including, chitosan (CS, derived from the polysaccharide chitin which forms the outer skeleton of insects, crabs, shrimps, and lobsters), poly(ε-caprolactone) (PCL), polyvinyl acetate (PVA), polylactide (PLLA), poly2-hydroxyl methacrylate (PHEMA), polyethylenimine (PEI), and polyethylene oxide (PEO).

Porous 3D scaffolds, which have a sponge-like structure, were made by freeze drying the material. Only the polymer mix CS/PVAc/PLLA formed a scaffold with a strength suitable for replacing bone. The pore sizes ranged from 50-600 μm in size, which is suitable for allowing cell colonisation, blood vessel growth and bone tissue regeneration.

Richard Oreffo, Professor of Musculoskeletal Science at the University of Southampton, commented, "Fractures and bone loss due to trauma or disease are a significant clinical and socioeconomic problem. This collaboration between chemistry and medicine has identified unique candidate materials that support human bone stem cell growth and allow bone formation. Our collaborative strategy offers significant therapeutic implications."

Professor Mark Bradley, of the University of Edinburgh’s School of Chemistry, added, “We were able to make and look at a hundreds of candidate materials and rapidly whittle these down to one which is strong enough to replace bone and is also a suitable surface upon which to grow new bone.

“We are confident that this material could soon be helping to improve the quality of life for patients with severe bone injuries, and will help maintain the health of an ageing population.”

The study, published in the journal Advanced Functional Materials [1], was funded by the Biotechnology and Biological Sciences Research Council. This new discovery is the result of a seven-year partnership between the University of Southampton and the University of Edinburgh.


1. Khan F et al. Discovery and Evaluation of a Functional Ternary Polymer Blend for Bone Repair: Translation from a Microarray
to a Clinical Model. Advanced Functional Materials, 2013. DOI: 10.1002/adfm.201202710


To top