Researchers at the Columbia University School of Engineering and Applied Science have developed a new technique that is able to repair large bone defects in the head and face by using bone that was grown within the lab. These bones have been specifically designed for each patient and the particular defect that is being treated. This is the first time in history that researchers have grown living bone that is an exact replication to the original anatomical structure by using autologous stem cells taken from a small sample of fat from the patient.
Vunjak-Novakovic, director of Columbia’s Laboratory for Stem Cells and Tissue Engineering says the team has been able to show within a clinical-size porcine model of jaw repair that the bone, which was grown in vitro and then implanted, holds the ability to be able to regenerate seamlessly to a large defect while providing complete mechanical function. The need for this technology is massive, especially in the case of congenital defects such as trauma and bone repair after cancer surgery. The quality of the regenerative tissue, including its vascularization with blood perfusion, greatly exceeds what has been achieved in a variety of other approaches. This exciting step forward will help to improve regenerative medicine options for patients with craniofacial defects. The team hopes to begin clinical trials within the next few years.
The team of Vunjak-Novakovic is made up of researchers from Columbia Engineering’s Department of Biomedical Engineering, Columbia’s College of Dental Medicine, Louisiana State University and Tulane University School of Medicine. The group fabricated a scaffold and bioreactor chamber that was based on images of the weight-bearing jaw defect in order to provide an anatomical fit that was just like the original. The human-made scaffold allowed bones to form without any need of growth factors and provided function parallel to before. Then they isolated the step cells of each recipient using a small fat aspirate and within the matter of three short weeks, were able to form a bone within a scaffold made from bone matrix, inside a custom designed perfused bioreactor. Bioreactors with the living bone were shipped across the country to be implanted in order to mimic logistics of clinical applications.
Researchers did not expect that the bone, when implanted, would over time start to become replaced by new bone that the body formed on its own accord. This wasn’t thought possible, as the implantation was made of scaffold, not cells. Vunjak-Novakovic says the lab grown living bones helps to serve as a template for active bone remodeling instead of a definitive implant. This is a feature that makes their implant an important part of the patient’s own bone, letting it adapt to changes that occur in the body throughout the rest of the patient’s life.
The team of researchers are now adding a cartilage layer into the bioengineered living bone tissue in order to study bone regeneration in complex defects of the head and face. They are advancing their current technology through the help of preclinical trials and are in the planning stages with the FDA for official clinical trials with the help of their company epiBone.
Lead author of the study, Sarindr Bhumiratana says the project is intriguing, energizing and inspiring due to its innovative research that may play a large part in the future of the human race. Vunjak-Novakovic says today, tissue engineering is changing the way we go about repairing tissue, how we drug test and even disease modeling. Within all of these diverse areas, she adds, we are now able to put the cells to work for us and create tissues by providing bioengineered environments that mimic their native milieu.