An Intelligent Degradable Polymer Composite Which Closely Matches Bone

Polyhydroxybutyrate (PHB) and its copolymers with polyhydroxyvalerate (PHV) are a range of slowly degrading polyesters with potential for use in orthopaedic surgery. The polymer degradation profile is unpredictable and thus a composite of PHB/7 % PHV and a completely soluble phosphate based glass reinforcement was compounded. This glass may be produced with a defined solubility rate and this was shown to control the overall degradation of the PHB/glass composite, in terms of both mass loss and change in mechanical properties. The piezoelectric properties of the composite were examined and the strain generated potentials were seen to be of a similar order of magnitude to that of bone. In vivo studies were carried out and as with the in vitro work, the reaction could be closely correlated with the composite solubility. Furthermore, tissue reaction at various stages could be closely linked to the composite solubility.