Development of Polyurethane Copolymer Apply on Bone Tissue Engineering

Objectives: Polyurethane (PU) materials have been extensively studied for biomedical applications because of its low cytotoxicity, good biocompatibility, mechanical property and suitable flexibility. Particularly, the combination of HAp and PU material has drawn considerable attention for bone repair. However, previous studies have found that HAp was difficult to mix uniformly with high viscosity PU structure. Moreover, HAp may affects the physical properties of PU bone graft and inhibit porous structure generation.
Methods: We use four-stage PU polymerization method to combine polyethylene glyco , Triethoxysilane and hydroxyapatite into PU material. Also, a uniform porous structure was generated during the spontaneous foaming reaction.
Results: In results, the characterization, surface morphology, mechanical strength and biocompatibility test of experimental groups ( PUsilan, PUsilane-15HAp, PUsilane-30HAp) are observed. FT-IR spectroscopy analysis show that the characteristic NCO group peak at 2270 cm was not detected, confirmed the successful of synthesis. The morphologies of all groups show a uniformly distributed porous structure from SEM image, and HAp crystals with uniform distribution were observed on the surface of the sponge in the group containing HAp. We also found that the porosity is proportional to the absorption rate. In mechanical test, it was found that the tensile strength of each group were greater than control group. In addition, the tensile strength of PUsilane-HAp groups, were proportional growth with HAp contained. In the MTT assay, all groups were passed the cytotoxicity test.
Conclusions: This proposed project will development the PU-HAp osteogenic bone scaffolds, that can not only solve clinical needs, but also assist cooperative manufacturers to develop a new generation of medical materials for clinical application.