Periodontal tissue regeneration by transplantation of adipose tissue-derived multi-lineage progenitor cells

Abstract

Several stem and progenitor cells are currently under investigation for their application in cell-based therapy for periodontal tissue regeneration. The present study evaluates periodontal tissue regeneration following transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) into periodontal tissue defects in beagle dogs.
ADMPCs were isolated from the greater omentum and their characteristics were identified using in vitro studies. Flow cytometric analysis demonstrated that the isolated ADMPCs were CD29⁺, CD44⁺, and CD90+. When cultured in mineralization-inducing media, these cells upregulated osteogenic genes and formed calcified nodules. Gene expression of the periodontal ligament specific gene, PLAP-1, was also increased. In addition, culture in adipogenic media resulted in accumulation of intracellular lipid droplets, suggesting multi-lineage differentiation capability of ADMPCs.
The efficacy of ADMPC transplantation for periodontal regeneration was evaluated using a beagle dog model. The furcation bone defects were surgically created and autologous transplantation of ADMPCs with fibrin gel was performed. Six weeks after transplantation, periodontal regeneration was analyzed using micro-CT, which showed a significant increase in bone formation at sites where ADMPCs were applied compared with control sites. Histological analysis revealed new cementum formation on the instrumented root surface was significantly increased following ADMPC transplantation and connective tissue fibers were inserted vertically in newly formed bone and cementum. Importantly, no instances of undesirable healing, such as root resorption or ankylosis, were observed at any sites examined. These results indicate that transplantation of ADMPCs with fibrin gel promotes periodontal tissue regeneration.