Evaluation of the ability of collagen-glycosaminoglycan scaffolds with or without mesenchymal stem cells to heal bone defects in Wistar rats

Purpose The aim of this experiment was to examine the capacity of collagen-glycosaminoglycan scaffolds, with or without mesenchymal stem cells, to satisfactorily repair a 5-mm rat calvarial defect. Methods Fifty-five Wistar rats were used in the study. The defects were either left empty to serve as controls (n= 7) or filled with cell-free scaffolds (n= 11), cell-seeded scaffolds that were pre-cultured in standard culture medium (n= 13), cell-seeded scaffolds that were pre-cultured in osteoinductive factor-supplemented medium (n= 12) or particulate autogenous bone (n= 12). The animals were sacrificed at 12 weeks after surgery, and specimens were prepared for histomorphometric analysis. The linear bone healing and the bone area within the defect were measured. Results Comparable results were obtained using cell-free collagen-glycosaminoglycan scaffolds and autogenous bone both in terms of linear bone healing (P< 0.986) and area of new bone (P<0.846). While the test groups showed significantly more bone formation compared to the empty defect control group, the linear bone healing and area of new bone within the defect were significantly lower in the cell-seeded scaffolds than in the cell- free scaffolds. The results have demonstrated that a cell- free collagen-glycosaminoglycan scaffold is capable of repairing a 5-mm rat calvarial defect as effectively as autogenous bone and that seeding the scaffold with precultured mesenchymal stem cells prior to implantation offered no beneficial effect and resulted in incomplete healing of the defect. Conclusions The results thus suggest that the scaffold has immense potential for tissue repair showing favorable osteoconductive properties, biocompatibility and degradability.