Preparation of 3D interconnected macroporous hydroxyapatite scaffolds by PVA assisted foaming method

In this work, a simple method, called PVA assisted foaming method (PAF method), is for the first time reported to prepare 3D interconnected macroporous hydroxyapatite scaffolds (MHSs) without resorting to either porogens or templates or complicated chemical process. In this method, PVA-cryogels formed upon freezing is employed to set the air bubbles incorporated by the physical agitation and therefore the macroporous structures. After sintering, uniform and tuneable macropores in sizes of 90–130 μm with window pore sizes ranging from 20 to 70 μm can be facilely achieved. Moreover, balanced macroporosity (70–73%) and compressive strength of 1.8–3.1 MPa make the resultant MHSs promising materials for bone tissue engineering application. Simple modifications to this PAF method, e.g. applying an extra mechanical stirring or adding small amounts of surfactant (e.g. SDS) to PVA solution, enable further manipulation of the macroporous structures.