People may joke about someone having a steel plate in their head, but in the case of punctures to the skull, that often ends up actually being the case – the hole in the bone is plugged with a permanent titanium-based patch. Researchers from Germany’s Fraunhofer Institute for Laser Technology, however, have just announced the development of biodegradable patches that stimulate the skull into healing itself. As the bone grows back in, the patches disappear.

Called Resobone, the patch material is made from the synthetic polylactide, and is sized to fit each patient. The material is porous in nature, due to its lattice-like structure of microchannels. These channels are produced through the process of Selective Laser Melting, and provide a substrate for the surrounding bone to grow into. Resobone also contains granules of tricalcium phosphate, which aid in rigidity and stimulate bone growth. Over a period of months or even years, the bone will gradually replace the Resobone, until nothing but natural bone is left.

Resobone cannot stand up to severe stress, so its use will be limited primarily to facial, maxillary (upper jaw area) and cranial bones. So far, it has been able to close fissures up to 25 square centimeters in size. The patches can be created in anywhere from a few hours to over one night.

Not only should the use of Resobone result in less titanium plates, it should also mean shorter and fewer surgeries. Currently, doctors will sometimes take bits of bone off the patient’s pelvis in order to close smaller fissures. In the case of children with steel plates, follow-up surgeries are often necessary to upsize the plate as the child grows. Hopefully, both of these procedures will become much less common.

Fraunhofer’s work in this field holds similarities with Dr. Brian Amsden’s research into regrowing body parts such as tendons, and Dr. Jeremy Mao’s system for regrowing teeth.