July 18 (UPI) -- Combining segments of bone engineered from stem cells, scientists have developed a new technique for personalized bone grafts for patients with disease of injury.
The method, which was described Wednesday in the journal Scientific Reports by scientists at the New York Stem Cell Foundation Research Institute, is called Segmental Additive Tissue Engineering.
The need for bone grafts includes fractures due to bone disease, weakening bones as people get older, genetic malformation and injuries from car accidents, domestic violence and military combat.
"We are hopeful that SATE will one day be able to improve the lives of the millions of people suffering from bone injury due to trauma, cancer, osteoporosis, osteonecrosis, and other devastating conditions," Dr. Susan L. Solomon, the CEO of NYSCF, said in a press release. "Our goal is to help these patients return to normal life, and by leveraging the power of regenerative medicine, SATE brings us one step closer to reaching that goal."
Bone problems are now treated with synthetic substitutes or bone grafts taken from a bone bank or another part of the patient's body, but the grafts often lead to immune rejection, don't form connective tissue or vasculature, and they can be outgrown by pediatric patients.
Previously, bone grafts from patient stem cells were difficult to bioengineer in the necessary size and shape, the researchers said.
"As the size of the defect that needs to be replaced gets larger, it becomes harder to reproducibly create a graft that can move from the lab to the clinic," said first author Dr. Martina Sladkova, an NYSCF researcher, . "We wanted to see if we could instead engineer smaller segments of bone individually and then combine them to create a graft that overcomes the current limitations in the size and shape of a bone that can be grown in the lab."
The researchers engineered a graft for a defect in the femur of a rabbit that affected about 30 percent of the bone's total volume. First, they scanned the femur to assess the size and shape of the defect and made a model of the graft. The model was then broken into smaller segments and customized scaffolds for each were created.
These scaffolds were fitted with human induced pluripotent stem cells into a bioreactor specially designed to accommodate bone grafts in different sizes.
After the cells integrated and grew within the scaffold, the segments were combined into one mechanically stable graft using biocompatible bone adhesives or other orthopedic devices.
"Bone defects obtained in disease or injury are a growing issue, and having effective treatment options in place for personalized relief, no matter the severity of a patient's condition, is of critical importance," said NYSCF's Dr. Giuseppe de Peppo.