Update: NEW FACES

A pioneering polymer and mineral implant, which readily bonds with bone without causing adverse reactions, has helped surgeons to rebuild the faces of children injured in accidents or born with serious disfigurements. Developed by UK and Russian scientists, ‘PolyHap’ implants have been used on around 50 children, including a baby with a jaw tumour and a 12-year-old girl who had been barely able to open her mouth from birth.

The PolyHap implants combine a polymer commonly used in dentistry and a mineral-like substance called hydroxyapatite, which can integrate into bone structures and support bone growth without breaking down or dissolving. The collaborating scientists also found a way to increase porosity – important for new bone growth – and to clean out toxins from the polymer implants using high-pressure carbon dioxide.

The implants were developed by teams led by Dr Vladimir Popov from the Institute of Laser and Information Technology in Troitsk, near Moscow, and Professor Steve Howdle of Nottingham University.

When a child is assessed for an operation at the St Vladimir Children’s Hospital, Moscow, scientists use advanced imaging and laser-based techniques (laser stereolithography) to create a three-dimensional plastic cast of the damaged area. Having assessed, with the surgeon, how much bone needs to be removed, the scientists then mould the individual PolyHap implants.

Current Wellcome Trust-funded research is targeted at the use of a new laser-based process (sintering) to create implants from biodegradable polymers and incorporating very delicate growth hormones to improve the performance of the implants.

External links

• Popov VK et al. Laser stereolithography and supercritical fluid processing for custom-designed implant fabrication. J Mater Sci Mater Med 2004;15(2):123–8.