Hydroxyapatite 3-Hydroxybutyrate

Wang, Y. W. et al. Evaluation of three-dimensional scaffolds made of blends of hydroxyapatite and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) for bone reconstruction 5iomafer 2005, 26(8), 899-904 (a). 

Coskun, S. Korkusuz, F. and Hasirci, V. Hydroxyapatite reinforced poly(3-hydroxy-butyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvaleiate) based degradable composite bone plate. J. Biomater. Sci. Polym. Edn. 2005,16(12), 1485-1502. 

An important development of orthopaedic implants has been the development of artificial composites, which when combined with biomolecules will induce osteogenesis. The properties of hydroxyapatite (HA) materials have been studied over the years with a view to increasing elasticity. Because biocompatibility has been a problem when HA has been combined with various polyethylenes and polysulphones, polyhydroxyalkanoates (PHAs) and its chemical composites, a polymer of hydroxybutyric acid (PHB), copolymers of hydroxybutyric acid and... 

PCL was also blended with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) copolymers on a small two-roll mill for 5 min at 140 °C (12% HV) or 128 °C (20% HV). The blends were injection moulded to produce tensile test samples. Samples were prepared in the presence of 1 wt % hydroxyapatite as a crystal nucleating agent and to reduce sample preparation time. For both copolymers, the addition of PCL (10 wt %) reduced the initial modulus and tensile strength (Table 12). Samples containing 90 wt % of PCL exhibited properties very similar to those of PCL and the effects were attributed to phase separation from the blends brought about by PHBV crystallisation at temperatures exceeding T for PCL. That is, the samples show immiscibility. Even blends containing 10 wt % PCL samples aimealed in aqueous media or in an oven showed the presence of crystalline PCL. 

---