Comparison of mesenchymal stem cell sheets and chondrocyte sheets in a rabbit growth plate injury model

Background/aim: The treatment of posttraumatic deformities and differences in length between the extremities resulting from physeal injury remains controversial. The aims of this study were to compare the efficacy of tissue-engineered, monolayer, and allogeneic mesenchymal stem cell sheets and chondrocyte sheets for physeal arrest treatment and to investigate cell sheet technology as a novel method for cell transplantation in physeal cartilage repair. Materials and methods: A proximal tibial physeal injury was induced in New Zealand rabbits. Allogeneic mesenchymal stem cells (MSCs) and chondrocytes were cultured in temperature-responsive culture dishes and applied to the iatrogenic partial growth plate defects in single-sheet grafts (cell sheets). Treatment efficacy was determined using radiological measurements, as well as histological and immunohistochemical staining. Results: Treatment with MSCs and chondrocytes prevented endochondral ossification in the physeal plate, and bone growth resumed after treatment in both the MSC and chondrocyte cell groups. We found significant differences in radiological evaluations between pre- and posttreatment measurements in both MSC and chondrocyte groups. Transplanted cells were observed in the damaged area in both of the groups, which differentiated in the direction of growth plate cartilage. Conclusion: Our results support the hypothesis that MSC or chondrocyte transplantation using the cell-sheet technique described in the present study aids in the regeneration of cartilage tissue during physeal arrest after growth plate damage.

Investigation of the differentiation potential of pericyte cells as an alternative source of mesenchymal stem cells.

BACKGROUND: The mesenchymal stem cells (MSCs) with characterized by their multipotency and capacity to differentiate into various tissue cell types, have led to their incorporation in regenerative medicine research. However, the limited numbers of MSCs in the human body and their diverse differentiation capabilities in tissues highlight the need for exploring alternative regenerative cell sources. In this study, therefore, we conducted molecular level examinations to determine whether pericytes, specialized cell communities situated near blood vessels, could serve as a substitute for human bone marrow-derived mesenchymal stem cells (hBM-MSCs). In this context, the potential application of pericytes surrounds the vessels when MSCs are insufficient for functional purposes. METHODS: The pericytes utilized in this investigation were derived from the placenta and characterized at the third passage. Similarly, the hBM-MSCs were also characterized at the third passage. The pluripotent properties of the two cell types were assessed at the gene expression level. Thereafter, both pericytes and hBM-MSCs were directed towards adipogenic, osteogenic and chondrogenic differentiation. The cells in both groups were examined on days 7, 14, and, 21 and their differentiation status was compared both immunohistochemically and through gene expression analysis. RESULTS: Upon comparing the pluripotency characteristics of placental pericytes and hBM-MSCs, it was discovered that there was a substantial upregulation of the pluripotency genes FoxD3, Sox2, ZPF42, UTF1, and, Lin28 in both cell types. However, no significant expression of the genes Msx1, Nr6a1, Pdx1, and, GATA6 was observed in either cell type. It was also noted that pericytes differentiate into adipogenic, osteogenic and, chondrogenic lineages similar to hBM-MSCs. DISCUSSION: As a result, it has been determined that pericytes exhibit high differentiation and proliferation properties similar to those of MSCs, and therefore can be considered a suitable alternative cell source for regenerative medicine and tissue engineering research, in cases where MSCs are not available or insufficient. It is notable that pericytes have been suggested as a potential substitute in studies where MSCs are lacking.