Porous 3D bioscaffolds by adaptive foam reticulation

Highly interconnected and 3D porous hydroxyapatite scaffolds with controllable macroporosity and microporosity have been produced using the adaptive foam reticulation technique, combining foam reticulation and freeze casting methodologies. Process optimized macropores were generated using a polymeric template while micropores are introduced by the sublimation of a porogen, in this instance camphene. The macropore (100–600 µm) and strut (20–100 µm) sizes of the bioceramic produced compares favorably with the template pore (200–600 µm) and strut (30–80 µm) sizes. X-ray diffraction analysis indicated a phase change from hydroxyapatite to whitlockite, a calcium-deficient phosphate incorporating magnesium and iron ions. Increasing the number of coatings and/or sintering temperature resulted in the increase of scaffold strength while reducing the pore size. Variations to the amount of porogen did not affect the macrostructure of the scaffolds and led to the controllable introduction of microporosity to the struts. Osteoblast-like MG-63 cell culture and assay tests indicated that the scaffolds are not cytotoxic and suitable for use as bone grafts.