The effect of mesenchymal stem cells, demineralized bone graft and platelet-rich plasma on osteogenesis in rat tibia defects

Aim: Deformities of the jaw and face are often caused by infection, inflammation, and cystic and neoplastic pathological conditions. Defects with various aetiologies should be repaired promptly using the most appropriate approach to reconstruct the anatomical form. To treat defects, bone grafts with various combinations have been used. In particular, combinations including cellular products to enhance osteogenic properties have been implemented. In this study, we aimed to investigate the effects of different materials and cells on bone defects by using mesenchymal stem cells (MSCs), which are thought to have a positive effect on healing, demineralized bone graft (DMB) and platelet-rich plasma (PRP). Methodology: We used 55 female rats weighing between 200-250 g, four of which were used to obtain platelet-rich plasma. The remaining animals were divided into five groups. Group I (n = 6) was the operative control group, Group II (n = 24) was given DMB, Group III (n = 24) was given DMB+PRP, Group IV (n = 24) was given MSC+DBG and Group V (n = 24) was given DMB+PRP+MSC applied to rat tibial defects (10 mm x 3 mm x 2 mm). Results: Statistically significant differences were observed in bone osteoblastic activity in tibia defects among the groups (p<0.05). Conclusion: Bone regeneration was significantly improved in groups where MSCs were used in combination with DMB and PRP. How to cite this article: Erdoğmuş Z, Gülsün B. The effect of mesenchymal stem cells, demıneralızed bone graft and platelet-rıch plasma on osteogenesıs ın rat tıbıa defects. Int Dent Res 2021;11(Suppl.1):47-55. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.8 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Bone Tissue Response to Different Grown Crystal Batches of Octacalcium Phosphate in Rat Long Bone Intramedullary Canal Area

The microstructure of biomaterials influences the cellular and biological responses in the bone. Octacalcium phosphate (OCP) exhibits higher biodegradability and osteoconductivity than hydroxyapatite (HA) during the conversion process from OCP to HA. However, the effect of the microstructure of OCP crystals on long tubular bones has not been clarified. In this study, two types of OCPs with different microstructures, fine-OCP (F-OCP) and coarse-OCP (C-OCP), were implanted in rat tibia for 4 weeks. F-OCP promoted cortical bone regeneration compared with C-OCP. The osteoclasts appearance was significantly higher in the C-OCP group than in the control group (defect only) at 1-week post-implantation. To investigate whether the solubility equilibrium depends on the different particle sizes of OCPs, Nano-OCP, which consisted of nanometer-sized OCPs, was prepared. The degree of supersaturation (DS) tended to decrease modestly in the order of C-OCP, F-OCP, and Nano-OCP with respect to HA and OCP in Tris-HCl buffer. F-OCP showed a higher phosphate ion concentration and lower calcium ion concentration after immersion in the buffer than C-OCP. The crystal structures of both OCPs tended to be converted to HA by rat abdominal implantation. These results suggest that differences in the microstructure of OCPs may affect osteoclastogenesis and result in osteoconductivity of this material in long tubular bone by altering dissolution behavior.

The Expression of Angiopoietin-1 and -2 in the Osteogenesis of Mesenchymal Stem Cells

Objective: The objectives of this study are to clarify whether rat bone marrow derived Mesenchymal stem cells (MSCs) express Ang1 and Ang2 and their expression in the process of osteogenesis in vitro. Material and Methods: MSCs were cultured from rat tibia bone marrow cells and the hemopoietic stem cells were deplete by consistently replacement of the culture medium. The MSCs were induced osteogenesis with mineralization conditional medium and Immunohistochemical and immunofluorescent staining were performed to assess the expression of Ang1 and Ang2. Results: The method used to expand rat MSCs in vitro was applicable, and the cell morphology is spindle-like shape that is consistent with the privous reports. The immunohistochemical staining results showed that both Ang1 and Ang2 were expressed by rat MSCs. Both Ang1 and Ang2 were up-regulated in the process of osteogenesis of rat MSCs. Conclusion: Rat MSCs express both Ang1 and Ang2 which might play critical roles in the osteogenesis in vitro.

Guided bone regeneration with a gelatin layer and adenoviral delivery of c-myb enhances bone healing in rat tibia

Aim: Bone healing becomes problematic during certain states, such as trauma. This study verifies whether the application of c-myb with gelatin promotes bone healing during bone injuries. Materials & methods: A biodegradable membrane was modified with adenoviral vector c-myb ( Ad/c-myb) and gelatin and applied in the bone injury site of rat tibia. Results: c-myb enhanced osteogenic differentiation and mineralization in bone marrow stromal cells after induction with osteogenic media. In vivo examination of rat tibia after application of the biodegradable membrane with Ad/c-myb and a gelatin layer demonstrated increased bone volume, bone mineral density, new bone formation and osteogenic molecules, compared with Ad/LacZ. Conclusion: c-myb has the potential to assist bone healing and may be applicable to the treatment of bone during injury.