MADRID, 22 Abr. (EUROPA PRESS) –
Babies and newborn mice can naturally heal damage to the bones that form the top of the skull, but this ability is lost in adults. However, is it possible to recover it?
Now, in a new study published in the Proceedings of the National Academy of Sciences, researchers at the University of Pittsburgh in the United States have developed a novel method that promotes bone regeneration in mice without implanting bone tissue or biomaterials.
The technique uses a device similar to an orthodontic wire used to realign teeth to gently stretch the skull along its sutures, activating skeletal stem cells that reside in these undulating seams. In adult mice, the technique repaired damage to the skull that otherwise would not have healed on its own.
“Our method is inspired by babies because they have an amazing ability to regenerate bone defects in the calvarial bones that form the top of the skull,” explains lead author Giuseppe Intini, associate professor of periodontics and preventive dentistry at the School of Dentistry. de Pitt, a member of the McGowan Institute for Regenerative Medicine and an investigator at the UPMC Hillman Cancer Center.
“By taking advantage of the body’s own healing capacity with autotherapies, we can stimulate the bone to heal itself. We hope to use this research in the future to develop novel therapies for people,” the researcher has advanced.
Trauma, birth defects, and surgery to treat cancer or other diseases are common causes of damage to the skull. After two years of age, these lesions do not heal on their own.
“In babies, the calvarial bones are not completely fused, so the sutures where the stem cells reside are still open,” explains Intini. “We wondered if the unfused sutures had anything to do with the bone regenerative capacity seen in infants and hypothesized that we could reverse it in adults by mechanically opening the sutures to activate the stem cell niche and increase their number.” has detailed.
In mice — which have cranial development very similar to humans — the researchers used a device called a bone distraction device to carefully apply a controlled tensile force to the calvarial bones, strong enough to slightly widen the sutures but not enough to cause a fracture.
Using single-cell RNA sequencing and live imaging microscopy, they found that the number of stem cells in the flared sutures of these animals increased fourfold. As a result, mice treated with the device regenerated bone to heal a large defect in the skull.
“If the stem cell niche can be effectively activated, their number can be increased and the regeneration of bone defects can be maintained,” says Intini. “Surprisingly, we showed that the defect can heal even if it is away from the suture,” she said.
Although the method was effective in curing 2-month-old skeletally mature mice, the age that roughly equals young adulthood in humans, it did not work in 10-month-old, or middle-aged, rodents.
“In older mice, the number of stem cells in the calvarial sutures is very low, so expanding this niche is not as effective in enhancing healing capacity,” Intini explained. “Overcoming this challenge is one of the focuses of future research,” she added.
Current treatments for damage to the skull often involve bone grafting or the implantation of biomaterials that act as scaffolds for bone regeneration, but these approaches are not always effective and carry risks, Intini has warned.
The researchers are studying how to use their findings in novel therapies for people to heal not only head injuries, but also fractures of long bones such as the femur.
Bone distraction devices are already used to treat certain conditions, such as craniosynostosis, a birth defect in which the calvarial bones fuse too early, so expanding this technique to promote bone regeneration could be one of the future goals of clinical trials. Intini and his team are also investigating non-mechanical methods to activate skeletal stem cells, such as drugs.