Macroporous sol–gel hydroxyapatite moulding via confinement into shaped acrylate–acrylamide copolymers

Polyacrylate salts and polyacrylamide have been extensively used for absorbing and/or retaining large amounts of water and/or ionic species. Herein, we propose the use of this polymers’ swelling capability as a new way to obtain porous spheres of nanocrystalline hydroxyapatite (HA). Macroporous nanostructured HA with a pore size between 1 and 500 μm is obtained when using the hydrogel as template. The removal of the organic template gives rise to the material in the form of a sphere which size and shape can be determined by the template contour. The use of this type of polymer constitutes not only an easy way to obtain HA beads but it would be also possible to form scaffolds with different shapes and sizes due to the versatility of the polymer. Degradation and bioactivity tests of the ceramic material have been performed showing an enhanced bioactivity and a suitable degradation rate to be applied in bone tissue engineering.