Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells with Platelet-Rich Plasma Accelerate Distraction Osteogenesis in A Canine Model

Abstract

Objective: Distraction osteogenesis (DO) is a surgical procedure used to generate large volumes of new bone for limb lengthening.

Materials and methods: In this animal experimental study, a 30% lengthening of the left tibia (mean distraction distance: 60.8 mm) was performed in ten adult male dogs by callus distraction after osteotomy and application of an Ilizarov fixator. Distraction was started on postoperative day seven with a distraction rate of 0.5 mm twice per day and carried out at a rate of 1.5 mm per day until the end of the study. Autologous bone marrow mesenchymal stem cells (BM-MSCs) and platelet-rich plasma (PRP) as the treatment group (n=5) or PRP alone (control group, n=5) were injected into the distracted callus at the middle and end of the distraction period. At the end of the consolidation period, the dogs were sacrificed after which computerized tomography (CT) and histomorphometric evaluations were performed.

Results: Radiographic evaluationsrevealed that the amount and quality of callus formations were significantly higher in the treatment group (P<0.05). As measured by CT scan, the healing parametersin dogs of the treatment group were significantly greater (P<0.05). New bone formation in the treatment group was significantly higher (P<0.05).

Conclusion: The present study showed that the transplantation of BM-MSCs positively affects early bony consolidation in DO. The use of MSCs might allow a shortened period of consolidation and therefore permit earlier device removal.

Keywords: Autologous Transplantation; Bone Lengthening; Distraction Osteogenesis; Mesenchymal Stem Cells; Platelet-Rich Plasma.

Fig.1

Mesenchymal stem cell (MSCs) culture. A. Photomicrograph of undifferentiated MSCs in primary culture at day 5 (bar=100 μm), B. Photomicrograph of undifferentiated MSCs in confluent passage-3 culture (bar=200 μm), C. Inosteogenic culture, mineralized matrix formed by passage-3 MSCs stained red by the alizarin red staining method (bar=100 μm), D. In adipogenic culture, lipid droplet developed in passage-3 MSCs stained red with the Oil red O staining method (bar=100 μm) and E. In chondrogenic culture, the matrix deposited among passage-3 MSCs stained purple by the toluidine blue staining method (bar=100 μm).

Fig.2

New bone formation was observed in radiograph obtained four weeks after surgery.

Fig.3

Histomorphometry of the new bone formation in the treatment and control groups. A. Photomicrographs of the peripheral zone fromthe treatment, B. and control group. Width, length, maturation and quality of the formed trabeculae in treatment group are more prominent compared to the control group [hematoxylin and eosin (H&E), bar =100 μm] and C. A graph indicating the relative quantity of newly formed bone in the treatment and control groups. There were significant differences between these groups (P<0.05).