Washington: In a first, scientists have grown a living bone in the lab to repair large defects in the head and face of patient, taking a step forward in improving
treatments for people with craniofacial defects.
A new technique developed by Gordana Vunjak-Novakovic, professor at Columbia University, uses autologous stem cells derived from a small sample of the recipient's fat and precisely replicates the original anatomical structure of the
bone. "We've been able to show, in a clinical-size porcine model of jaw repair, that this bone, grown in vitro and then implanted, can seamlessly regenerate a large defect while providing mechanical function," said Vunjak-Novakovic.
"The quality of the regenerated tissue, including vascularisation with blood perfusion, exceeds what has been achieved using other approaches," she said. This is a step forward in improving regenerative medicine options for patients with craniofacial defects, she added. Researchers, including those from Louisiana State University and Tulane University in the US, fabricated a scaffold and bioreactor chamber based on images of the jaw defect, to provide a perfect anatomical fit.
The scaffold they built enabled bone formation without the use of growth factors, and also provided mechanical function, both of which are unique advantages for clinical application. They then isolated the recipient's own stem cells from a small fat aspirate and, in just three weeks, formed the bone within a scaffold made from bone matrix, in a custom-designed perfused bioreactor.
An unexpected outcome was that the lab-grown bone, when implanted, was gradually replaced by new bone formed by the body, a result not seen with the implantation of a scaffold alone, without cells. "Our lab-grown living bone serves as an 'instructive' template for active bone remodelling rather than as a definitive implant," said Vunjak-Novakovic. "This feature is what makes our implant an integral part of the patient's own bone, allowing it to actively adapt to changes in the body throughout its life," she said.
Researchers are now including a cartilage layer in the bio-engineered living bone tissue to study bone regeneration in complex defects of the head and face. "Today, tissue engineering is truly changing the way we approach tissue repair, drug testing, disease modelling," Vunjak-Novakovic said. "In all these diverse areas, we now can put the cells to work for us and make tissues, by providing bio-engineered environments that mimic their native milieu," she added. The study is published in Science Translational Medicine.
