Comparative evaluation of fracture healing potential of differentiated and undifferentiated guinea pig and canine bone marrow-derived mesenchymal stem cells in a guinea pig model.

BACKGROUND AND AIM: This work was conducted to compare the therapeutic potential of undifferentiated and osteogenic differentiated canine (xenogeneic) and guinea pig (allogeneic) BMSCs in fracture healing using guinea pig as a model. MATERIALS AND METHODS: A well-characterized homogenous population of third passage mesenchymal stem cells of bone marrow origin was used in all the experiments. MSCs from both the species, i.e., canine and guinea pigs, were differentiated and characterized. Expression of MHC I and II along with co-stimulatory molecules was assessed based on relative mRNA expression. The osteogenic differentiated and undifferentiated MSCs from both species were used for evaluating fracture healing in the guinea pig model. The healing potential was assessed based on radiographic, histopathology, and clinical observations. RESULTS: BMSCs from both species expressed MSC surface antigens and successfully differentiated to osteogenic, chondrogenic, and adipogenic lineages. The mRNA expression of class I and II MHC molecules in all the three lineages showed no significant (p > 0.05) differences after differentiating to adipogenic, chondrogenic, and osteogenic lineages. Radiographic and clinical examination revealed that MSCs therapy significantly improved bone fracture healing with a non-significant (p > 0.05) difference between differentiated and undifferentiated BMSCs. In addition, allogeneic MSCs therapy performed better than xenogeneic therapy. CONCLUSION: MSCs remained hypo immunogenic after differentiation and have comparable fracture healing potential though allogeneic MSCs have better therapeutic potential than xenogenic MSCs.

Effect of cryopreservation on therapeutic potential of canine bone marrow derived mesenchymal stem cells augmented mesh scaffold for wound healing in guinea pig.

The objective of this study was to compare the therapeutic potential of canine bone marrow derived mesenchymal stem cells (BM MSCs) augmented mesh scaffold for wound healing potential in guinea pig before and after cryopreservation. Bone marrow aspirate was obtained from healthy dogs and culture was expanded in vitro. MSCs augmented mesh scaffold were cryopreserved for 30 days and then used for therapeutic purposes. Both fresh and frozen thaw MSCs augmented mesh scaffold along with fresh MSCs were used for therapeutic purposes in guinea pig. No significant (P > 0.05) difference was observed in population doubling time (PDT) among fresh and frozen thawed BM MSCs. Both fresh and frozen thawed BM MSCs expressed cell surface markers (CD73, CD90, and CD105), and did not express CD34 as was confirmed by Immunocytochemistry and Real-Time Polymerase Chain Reaction. The fresh and frozen thawed BM MSCs successfully differentiated into osteogenic, chondrogenic and adipogenic lineages. Therapeutic results revealed that the percent wound contraction on day 14 was more than 65 % for the mesh augmented with MSCs as well as freshly injected MSCs group as against 33-34 % in the control group. Healed wound quality parameters viz. surface epithelium, neovascularization, and collagen characteristics were better for the mesh augmented with MSCs as well as freshly injected MSCs group compared to the control group. No significant difference was noted among fresh and frozen thawed BM MSCs group and fresh MSCs injected group. Thus, it is concluded from this study that canine BM MSCs augmented mesh scaffold both fresh and frozen thaw can be used for quality wound healing.