70% of bone is made of hydroxyapatite – a calcium phosphate mineral. This is what has allowed calcium phosphate cement (CPC) to be used as a bone substitute in surgery for almost 100 years. The reason this hasn’t yet been used to treat degenerative diseases is because we didn’t know how to make the cement with pores larger than 50 nanometers – i.e. “macroporous”.
By preparing the CPC with Si-HPMC solution (a silanized hydrogel foaming agent) and air, French scientists at the University of Nantes were able to create an injectable, self-setting, macroporous calcium phosphate foam that has the potential to treat degenerative diseases such as osteoporosis.