Use of allogenic stem cells for the prevention of bone bridge formation in miniature pigs.

This study appears from an experiment previously carried out in New Zealand white rabbits. Allogenic mesenchymal stem cells (MSCs) were transplanted into an iatrogenically-created defect in the lateral section of the distal physis of the left femur in 10 miniature pigs. The right femur with the same defect served as a control. To transfer MSCs, a freshly prepared porous scaffold was used, based on collagen and chitosan, constituting a compact tube into which MSCs were implanted. The pigs were euthanized four months after the transplantation. On average, the left femur with transplanted MSCs grew more in length (0.56+/-0.14 cm) compared with right femurs with physeal defect without transplanted MSCs (0.14+/-0.3 cm). The average angular (valgus) deformity of the left femur had an angle point of 0.78 degrees , following measurement and X-ray examination, whereas in the right femur without transplantation it was 3.7 degrees. The initial results indicate that preventive transplantation of MSCs into a physeal defect may prevent valgus deformity formation and probably also reduce disorders of the longitudinal bone growth. This part of our experiment is significant in the effort to advance MSCs application in human medicine by using pig as a model, which is the next step after experimenting on rabbits.