Potential Capacity of Cord Blood-Derived Mesenchymal Stem Cells in the Regeneration of Bone Defects in Rabbits

Periodontal disease in its advanced chronic forms، can involve all or parts of periodontium. While periodontal diseases are accompanied with extensive destruction of periodontal tissues (include-ing cementum، alveolar bone، gingival and periodontal ligament)، the tissue has a limited ability to regenerate itself. Due to the limited regenerating capacity of the tissue، application of cells with high pote-ncy of regeneration may be for the treatm-ent of periodontal disease. Cord blood was collected from the umbilical cord vein of 30 mothers who gave informed consent. The isolated mononuclear cell layer was washed in PBS، and then re-suspended in growth medium. The cells were analyzed with flowcytometry for superficial mar-kers. Critical-sized (8 mm) calvarial defe-cts were created in the parietal bone of ad-ult rabbit. Defects were either left empty، treated with a collagen alone، or a collagen with human cord blood-derived mesenc-hymal stem cells (USSCs). Histology and histomorphometry were performed. USSCs were positive for the markers CD73 and CD105، negative for the marker CD34 and had the normal kary-otype 44XX. Quality of the regenerated bone and its connection to surrounding bone tissue were significantly improved in the treated rabbits. Discussion & Results of the study demonstrated that from the viewpoint of histomorphometric، the rate of lesion regeneration was about 90% higher in the treatment group and the complete reconst-ruction was accomplished after 8 weeks