Bone tissue defects that cannot heal via tissue regeneration can be filled using autograph, allograph or synthetic scaffold materials. For large defects, e.g. defects in the cranium or in long bones, healing of bone defects can be especially difficult. A wealth of bioceramic formulations and delivery forms have been suggested for use as bone void filler materials. Examples of bone void fillers include cements, e.g. apatite and brushite based cements, and powders or granules, e.g. β-TCP and apatite powders and granules. Delivery forms include injectable forms and granules packed directly into an open bone defect. Injectable cements have been proposed both as premixed versions and as formulations to be mixed in the operating room. One major drawback with the current suggested material formulations is their relatively low bone induction capability. This is especially important in repair of large and complex bone defects, as in the cranium. Some bioceramic formulations which have been reported as having an ability to induce bone formation include hydroxyapatite (porous), biphasic calcium phosphate ceramics, tricalcium phosphate ceramic, calcium pyrophosphate and apatite cement formulations. In addition to these, bone induction capability of some calcium phosphate formulations has been very difficult to combine with a tailored resorption rate and a material handling technique that facilitates industrial use of the materials, e.g. in the operating room and/or for moulding of complex shapes.
Accordingly, there is an unmet need for a material that has a slow and optimal resorption rate in vivo and/or induces bone formation, and is easily handled in the operating room and/or when moulding complex shaped implants.