Bone replacements are frequently used to substitute damaged tissue resulting from trauma, disease or surgery. However, there are limitations and complications associated with the use of current therapies for bone grafts, which means there is an urgent need for bone substitutes. The aim of the EU-funded project 'Bioactive resorbable scaffolds for drug delivery in bone tissue engineering' (Bioress) was to address this need. Bone-tissue engineering is a relatively new field that combines biology and engineering to develop bone substitutes that restore and maintain the function of human bone tissue. Most bone substitutes require a bone scaffold. This is a three-dimensional (3D) porous structure that can be used as a bone graft. Scaffolds made of phosphate glasses are an attractive solution since they are restorable, i.e. they can be broken down and assimilated back into the human body. They are also biocompatible, bioactive and are able to support bone growth. Phosphate glasses were obtained using the traditional glass-making method of melting and quenching. The glasses were then used to produce macroporous 3D-scaffolds for bone regeneration. Project partners characterised the scaffolds in terms of microstructure, solubility, bioactivity and mechanical strength. They also evaluated biocompatibily in the laboratory using human bone marrow cells. The study showed that cells attached themselves to the scaffold and multiplied. More work is needed before clinical trials can begin. However, if successful then the next challenge will be to develop the advanced manufacturing systems that are required to fabricate the complex scaffolds with controlled distributions of materials and drugs to stimulate cell growth.