Synthetic 3D-printed bones for reconstructive surgery

Jakus AE et al. Hyperelastic "bone": A highly versatile, growth factor-free, osteoregenerative, scalable, and surgically friendly biomaterial. Science Translational Medicine. September 2016.

Bone implantation surgery is both challenging for doctors and a painful process for patients, especially children. It usually requires either harvesting existing bone tissue from elsewhere in the body, or using metallic implants. While these approaches may work for adults, they are not a permanent solution when used for growing children. In a recent study, scientists reported a 3D printable ink that forms a synthetic bone implant and induces bone generation and growth. This biomaterial is composed of a mix of 90% hydroxyapatite, a calcium mineral found in human bone, and 10% biodegradable polymer, which is commonly used in medical applications, including sutures. The key feature of this new hyper-elastic biomaterial is its ability to create porous structures where blood vessels and other cells can infiltrate to create a scaffold. Animal studies showed that when stem cells are placed on these scaffolds, they turn into bone cells and initiate the regeneration process. Additional factors can also be easily integrated into the biomaterial, such as antibiotics to prevent post-surgery infections or growth factors to further enhance the regeneration process. The advantage of 3D printing technology will enable doctors to create personalized bone structures with custom shapes and properties for each patient.  In the near future, hospitals with biomaterial and 3D printing facilities may revolutionize the field of craniofacial and orthopedic surgery.

Gene behind “sixth sense” discovered

Chesler AT et al. The Role of PIEZO2 in Human Mechanosensation. The New England Journal of Medicine. September 2016

Close your eyes and bring your finger to your nose. It’s an easy task for almost all of us, isn’t it? Awareness of the position of one’s body in space is called proprioception, also commonly known as the “sixth sense.” A recent study describes the cases of two patients who lack proprioception. These patients could not walk, keep their balance, or even touch their noses when blindfolded. Genetic analyses revealed that both patients had mutations on a gene called PIEZO2, suggesting that this gene is responsible for the sense of touch and proprioception in humans. Further investigation of the PIEZO2 gene showed that it controls mechanosensation by generating nerve signals in response to any force touching the skin, thus allowing us to sense the touch. The patients seem to compensate for a lack of proprioception by relying primarily on vision. While these patients have non-functional PIEZ02 genes, there is an intriguing possibility that there could be other variations of this gene in the human population, which may generate a spectrum of symptoms from superior athletic performance to clumsiness, depending on the P