Polyurethane composite foams with β-tricalcium phosphate for biomedical applications

Biocompatibility, bioactivity, bioconductivity and injectability are the most valuable features of biodegradable polyurethanes for orthopaedic applications. Injectable biomaterials may be used in bone tissue engineering for minimally invasive therapies and other medical applications. Polyurethane composites have been synthesized with concentration of beta-tricalcium phosphate in the range of 0-30 wt%. Incorporation of beta-tricalcium phosphate leads to an increased glass temperature of soft segments while a decrease of glass temperature was observed for hard segments. Moreover, addition of -tricalcium phosphate caused an increase in the thermal stability of polyurethane matrix. Porosity has ranged between 27 and 53%. The mechanical and thermal properties of the polyurethane/beta-tricalcium phosphate composite samples have been investigated. In vitro degradation tests have been carried out in water, Ringer's solution and phosphate buffered saline. After 2 weeks incubation in simulated body fluid, scanning electron microscopy observations showed the presence of an inorganic phase deposition which might indicate good bioactivity of the composites. The relationships between their properties and bone regeneration quality were discussed as the composites demonstrate vast potential to be used as injectable scaffolds for bone repair.