179 Xenogeneic and Allogeneic Mesenchymal Stem Cell Transplantation for Treatment of Tibial Bone Fracture in Mice

Abstract

Among stem cells, mesenchymal stem cells (MSC) are best suited for therapeutic purposes because of their immunomodulatory properties, ability to be isolated from adult animal at any stage, ease of propagation in the laboratory, and so on. The present study was carried out to isolate and characterise MSC from adipose tissue of mouse (Mus musculus), and to test their application for the treatment of fractured tibia bone in mouse. Cattle and buffalo MSC, already cultured and characterised in our laboratory, were used in the present study as xenogeneic MSC to observe the healing in mouse model. Murine Ad-MSC were isolated from mouse inguinal fat pad by enzymatic digestion method and cultured in growth enriching medium in standard culture conditions. To test the therapeutic potential of MSC, 24 mice were divided into 4 groups: control (C), allogeneic (A), cattle xenogeneic (CX), and buffalo xenogeneic (BX) with 6 mice (having tibial bone mechanical fractured) in each group, and had the corresponding MSC cells injected in the fracture area. The control group was not subjected to any kind of MSC treatment. Post-treatment, healing in all groups was examined for 36 days at different intervals (Days 1, 12, 24, and 36) via digital X-ray imaging. A bone healing score was assigned to each mouse per the protocol provided by RUST (Radiographic Union Scale in Tibial bone) fractures. The results of present study showed that murine Ad-MSC were positive for MSC-specific markers CD44, CD90, CD105, and negative for CD34 and CD45 via RT-PCR and immunocytochemistry. The Ad-MSC were also positive for the alkaline phosphatase staining. Statistical analysis, using Proc GLM (SAS Institute Inc., Cary, NC, USA), revealed that the bone healing was significantly different (P < 0.01) between group C (1.708 ± 0.059) and other groups [group A (2.125 ± 0.061), CX (2.167 ± 0.068), BX (2.250 ± 0.068)], suggesting that healing was greater in groups transplanted with MSC compared with control. However, healing between groups transplanted with MSC (A, CX, and BX) was not significantly different (P > 0.05). In conclusion, we have observed the healing potential of MSC in mouse model via allogeneic and xenogeneic MSC transplantation; the healing potential among the A, CX, and BX MSC groups was similar.