Adipose-Derived Mesenchymal Stem Cells Enhance Healing of Mandibular Defects in the Ramus of Swine

Purpose: This study investigated the effect of adipose-derived mesenchymal stem cells (ASCs) injected locally or systemically on the bone regeneration of a 10-mm-diameter cylindrical noncritical-size defect in the ramus of the pig mandible. Materials and Methods: Fifteen Yorkshire pigs, weighing 60 to 80 kg, received bilateral 10-mm-diameter cylindrical surgical defects in each ramus of the mandible. Pigs received 1) a direct injection into the defect of 2.5 million carboxy-fluorescein diacetate succinimidyl ester-labeled ASCs from 1 of 2 pig donors (n = 6); 2) an ear vein injection of 5 million carboxy-fluorescein diacetate succinimidyl ester-labeled ASCs from 1 of 2 pig donors (n = 6); or 3) an ear vein injection of culture Dulbecco's Modified Eagle's Medium without stem cells (control; n = 3). Pigs from each treatment were sacrificed at 1 hour, 2 weeks, or 4 weeks after surgery. Healing of the defect was evaluated by dual-energy x-ray absorptiometry, micro-computed tomography, fluorescent microscopy, and histology. Results: Bone healing was accelerated in the ASC-injected treatment groups at 2 and 4 weeks after surgery compared with the control pigs. Conclusions: Results from this animal model provide evidence that the injection of ASC locally into a bone defect or systemically can accelerate the healing of bone. (C) 2012 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 70:e193-e203, 2012