The Effects of Newly Formed Synthetic Collagen on Bone Regeneration in Pigs Calvarial Defects

Objectives: In bone regenerative medicines, variety of bioabsorbable materials have been developed and examined up to now. However, there are still high hurdles in the point of ethical issues and establishment of compliance with patients currently to apply bioresorbable materials derived from animals and humans to patients actually in Japan. Then, we developed a new bone material combined the mesenchymal stem cells (MSCs) derived from the pig marrow collected, separated, and adjusted in advance with synthetic collagen (SC), and performed evaluation as a scaffold of artificial collagen simultaneously with evaluation of the bone reproduction ability.
Methods: Three female miniature pigs (30 to 34 weeks of age) were used for the experiment. For the transplantation experiment, the cell group using SC as a scaffold, the group of only SC, and the group of only a bone defect as a control group, was produced. When pig osteoblast-like cells that had been induced for 7days to differentiate into bone were transplanted under the periosteum of the skull of the pigs.
Results: Although significant changes of all the groups were not observed in six weeks after the transplant, more significant new bone prominent formation in the cell group than that in other groups was observed in 18 weeks after the transplant, and the new bone was confirmed also in center of the missing part.
Conclusions: Bone formation materials that combine synthetic collagen as a scaffold with pig messenchymal stem cells have good osteogenic ability, and should be studies for clinical application