Preparation and characterization of porous hydroxyapatite/-cyclodextrin-based polyurethane composite scaffolds for bone tissue engineering

In this study, novel porous scaffolds containing hydroxyapatite and -cyclodextrin-based polyurethane were first successfully fabricated by polymerizing -cyclodextrin with hexamethylene diisocyanate and hydroxyapatite in situ for bone tissue engineering. The physicochemical and mechanical properties as well as cytocompatibility of porous scaffolds were investigated. The results showed that polyurethane reinforced with hydroxyapatite composites had cancellous bone-like porous structure. The mechanical strength of the scaffolds increased with increasing the hydroxyapatite content in scaffolds. Synthesized scaffolds (PU1, PUHA1, PU2, and PUHA2) presented compressive strength values of 0.87 +/- 0.24 MPa, 1.81 +/- 0.10 MPa, 6.16 +/- 0.89 MPa, and 12.95 +/- 2.05 MPa, respectively. The pore size and porosity of these scaffolds were suitable for bone regeneration. Cytocompatibility of composite scaffolds was proven via favorable interactions with MC3T3-E1 cells. The addition of hydroxyapatite into CD-based polyurethane scaffolds improved cell attachment, well-spread morphology, and higher proliferation. The hydroxyapatite-polyurethane scaffolds have the potential to be applied in bone repair and regeneration.