Comparison of regeneration between human bone marrow and adipose mesenchymal stem cells on treatment of critical size bone defect in sprague dawley rats

Aims: This study was to investigate the difference of osteogenic capacity between BMSC and ASC by quantifying the expression of Bone Morphogenetic Protein (BMP)-2 and BMP receptor (BMPR) II also the bone healing process by histomorphometry measurement. Study Design: This study was experimental study on animal (Sprague Dawley Rat). Place and Duration of Study: This study took place in Animal Laboratory of Indonesian Health Minister, Faculty of Medicine Universitas Indonesia, Department of Orthopaedic and Traumatology, Stem Cell Unit, and Department of Anatomical Pathology Cipto Mangunkusumo Hospital, and also Primate Study Center of Bogor Institute of Agriculture. Methodology: Eighteen Sprague dawley (SD) healthy rats were induced with 5 mm femoral bone defect, then divided into three equal groups (n=6) consist of Control, Implementation of 2×10⁶ BMSC + 5 cc Hydroxypatite (HA), and Implementation of 2×10⁶ ASC + 5cc HA. They were sacrificed after 2 weeks, then underwent histomorphometry assessment with Image-J. The measured paramater were total area of callus, % of osseous area, % of cartilage area, and % of fibrous area. The immunohistochemistry (IHC) measurement was assessed by staining intensity and immunoreactivity score (IRS). Results: The BMSC group showed higher expression of BMPR II compare to others. The expression of BMPR II was analyzed statistically and showed significant result (P= .04) among groups with median 4.00 ± 2.75. Both BMSC and ASC group have significantly better bone healing process compared with control group (P= .001). There are no significant differences between ASC and BMSC measured in % total callus area (P= 1.00), %Osseous area (P= 1.00), %Cartilage area (P= .49) and %Fibrous area (P= .18). Conclusion: ASC bone healing ability are similar to BMSC. BMP-2 and BMPR II are important but not sole contributing factor for bone healing.