Calcium phosphate cements (CPC) have long been available for repairing bone problems caused by disease or accidents; however, recently published research reveals that French scientists just dramatically enhanced CPC by developing a remarkable new injectable bone foam that not only repairs bone damage but also allows bone formation.
Pierre Weiss, from the University of Nantes, leads the research team in developing a type of CPC that is both self-setting and macroporous. In other words, the team has created a foaming agent that creates air bubbles in the CPC mixture. This is necessary because, if injectable cements don’t have cavities larger than 50 nanometers, it makes it difficult to do things like treat bone degeneration or strengthen cancellous bone—a porous, flexible tissue that gets progressively weaker with osteoporosis.
There are two syringes used to create this breakthrough foam. One contains monosodium phosphate and the other one has silanized-hydroxypropyl methylcellulose (a type of hydrogel). Both syringes are inserted at the same time to create a hydrogel foam to create larger pores. This foam is then inserted a syringe that is connected to another syringe that has CPC paste.
Together, these syringes create the foamed CPC paste.
Animal Testing and The Future of Bone Cement
The bone cement foam has already been tested in tiny defects found in the thighs of rabbits. The results showed that the foam has completely filled the bone defects in just one week. After 6 weeks, they discovered that the foam had created a scaffold to form new bones.
The team has also mentioned that their CPC paste “exhibits a good injectability and an excellent cohesion, which are needed for clinical application.”
Scientists still need to further study this new foam to measure how effective its role will be in repairing damaged bones as well as encouraging bone growth. However, there are definitely high hopes for this foam to prevent the rise of osteoporosis-related fractures.
Currently, this bone disease affects approximately eight million people across the globe, making it the top bone disease. Other common bone diseases include Paget's disease, Osteogenesis Imperfecta and bone cancer—ultimately, they also could be treated by using this new bone foam.
"There are quite a few groups working on this issue and different solutions proposed," said Eduardo Saiz, who investigates biomaterials for bone repair at Imperial College London, but wasn't involved in this study. "This could be one, the preliminary results are very interesting. If the research progresses well it could give surgeons an easy to use material for minimally invasive procedures, which will benefit clinical practice."