The bioactive foam can be molded to skull bone lost to injury, surgery, or birth defect. (Credit: Rensselaer Polytechnic Institute)

A team of researchers is developing a new material that can be used to replace skull bone lost to injury, surgery, or birth defect. The bioactive foam is malleable when exposed to warm saline, allowing surgeons to easily shape it to fit irregular defects in the skull, where it hardens in place. Once implanted in the skull, specially coated pores within the foam attract bone cells, naturally regenerating bone to replace the foam, which dissolves over time.

The foam — a shape memory polymer coated in a bioactive polydopamine — is intended as an alternative to materials currently used to treat cranio-maxillofacial gaps. The researchers are testing various formulations of the foam in vitro, recommending the most successful formulations for further preclinical testing and providing insights on why some foams are more (or less) successful in promoting bone growth. Their goal is to find the ideal formulation that maintains the amazing shape memory properties of the foam while providing the optimal environment for stimulating new bone formation.

The project began about five years ago, and has already shown good biocompatibility in preliminary tests in small animal models. Many more years of refinement and testing are required before a product reaches surgeons as a treatment option. They says that a moldable bone-promoting scaffold could have broad use if it’s successful because it takes advantage of the body’s own healing ability, and it’s a low-cost, ‘off the shelf’ solution that would not need to be pretailored to the individual defect.