Novel stem cell and PHBHHx approaches to tendon repair

Tendon injuries continue to be a financial burden on the health care system of many western countries, whilst also remaining common and a significant challenge within the orthopaedic discipline with no consensus of opinion on the best therapeutic regime to be employed. Many polymers have been investigated for use in tendon repair. A range of polymers have shown good integration with limited immune response. However, to date no implant has been capable of delivering the physical properties observed in native undamaged tendon. Many of the polymers implanted have resulted in re-rupture or reduced mechanical function. Therefore, improvements are required in the choice of polymer and mechanical properties of the polymer are required. One means of achieving such improvements is to utilise co-polymers such as PHBHHx, which have shown favourable elastic properties when the ratio of HHx to PHB has been increased. Therefore, a PHBHHx polymer based scaffold was investigated as a potential scaffold for tendon repair. Whilst, also investigating the potential of FGF-4, FGF-6 and FGF-8 to differentiate both human embryonic and mesenchymal stem cells towards a tenocyte-like lineage. Finally, an investigation into whether a controlled production of PHBHHx based nanoparticles could produce different nanoparticles sizes that can be predicted and result in differing release profiles. This may allow for the synthesis of size controlled nanoparticles capable of delivering differing drug concentrations and sustained release properties