[Preliminary study on treatment of mandibular osteoradionecrosis by autologous bone marrow mesenchymal stem cells in miniature pigs].

OBJECTIVE: To investigate the treatment effect of mandibular osteoradionecrosis (ORN) by autologous bone marrow mesenchymal stem cells (BMMSC) in miniature pigs. METHODS: Six miniature pigs with mandibular ORN (25 Gy) were used. BMMSC were separated and cultured in vitro and then implanted on to the premolded hydroxyapatite-tricalcium phosphate (HA-TCP). The BMMSC-HA-TCP complexes were implanted into the defective area of mandibular ORN in 4 animals. Implantation of only HA-TCP in 2 animals served as control. Gross observation, spiral CT, coronary CT and histopathologic examination were carried out. RESULTS: Fistula disappeared in animals with BMMSC-HA-TCP complexes 3 months after implantation, while fistula was found in controls. Spiral CT analysis showed that cortical bone repair were found 4 months after BMMSC-HA-TCP complexes implantation, while bone damage (cortical and cancellous bone fracture) increased in controls. Histopathologic examination revealed that 4 months later after BMMSC-HA-TCP complexes implantation, new bone formation and bone cells could be observed, but there was a large number of fibrous tissue and no new bone in controls. CONCLUSIONS: Transplantation of autologous BMMSC with HA-TCP may have therapeutic effect in the treatment of mandibular ORN.

[Expression and clinical significance of Cox-2 and XIAP in malignant tumors of the salivary gland].

PURPOSE: To detect the expression of Cox-2 and XIAP in adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) of salivary glands. To study the role and correlation between the expression of Cox-2 and XIAP in malignant tumors of salivary gland. METHODS: Immunohistochemical SP staining method was used to quantify the protein expression levels of Cox-2 and XIAP in 95 patients with malignant tumors of the salivary gland (50 ACCs,45 MECs),10 patients with pleomorphic adenoma and 10 persons with normal salivary gland tissues. SPSS17.0 software package was used to analyze the data. RESULTS: Cox-2 and XIAP were expressed strongly in malignant tumors of the salivary gland, while they not expressed in pleomorphic adenoma and normal salivary gland tissues. The expression of Cox-2 and XIAP in malignant tumors of salivary gland was correlated with clinical stage and lymphnode metastasis, while they not correlated with primary sites (P>0.05). CONCLUSIONS: The high expression of Cox-2 and XIAP in malignant tumors of salivary gland may play an important role in the development of malignant tumors of the salivary gland.

[The isolation and identification of bone marrow mesenchymal stem cells derived from rabbit mandible].

PURPOSE: To investigate the methods of isolation, culture and identification of BMMSCs derived from rabbit mandible. METHODS: BMMSCs were collected from rabbit mandible and isolated by density gradient centrifugation. Cells were adherently cultured in vitro, and P2 or P3 BMMSCs populations were collected and examined. Cell growth was observed by inverted microscopy; the propagation of BMMSCs were tested by MTT and a growth curve was drawn after statistical analysis; colony-forming unit-fibroblast(CFU-F) was detected by examination of colony formation; the potential of multi-directional differentiation into osteoblasts, adipocytes and skeletal muscle cells was estimated by pertinent methods; the surface marks of BMMSCs were detected by flow cytometry, the data was analysed using SPSS16.0 software package. RESULTS: The majority of adherent cells were long fusiform, and few were small triangle; the growth curve of BMMSCs showed that every passage experienced incubation period, log phase and platform period; the rate of colony formation was 37%. Growth of BMMSCs represented the appearance of CFU-F; BMMSCs after inducted differentiation showed osteogenic and adipogenic potential. The staining of mineralized nodules was positive by alizarin red S and the positive staining of oil red O appeared in lipid drops around cell nucleus. The staining of skeletal muscle cells was positive by desmin immunofluorescence; the cell surface marks assessed with flow cytometry indicated that these BMMSCs expressed CD90 and CD146 in high percentage (about 98.7% and 98.1%, respectively). CONCLUSIONS: The highly uniformed BMMSCs derived from rabbit mandible can be collected. These BMMSCs have the ability of self-replication and propagation, as well as potential of multi-directional differentiation in vitro.

[Research on the adipose-derived stem cells combined with the extract of Eucommiol scaffold material to repair the rabbit mandible defect].

OBJECTIVE: To investigate the effect of Eucommiol on osteogenic differentiation of adipose-derived stem cells (ADSCs), and the feasibility of applying in mandibular defects repair using ADSCs combined with the extract of Eucommiol scaffold material. METHODS: Forty-eight New Zealand rabbits were randomly divided into four groups and bilateral mandibular defect was prepared. Group A: Implanted the ADSCs combined with the extract of Eucommiol scaffold, group B: Implanted the ADSCs combined with hydroxyapatite materials, group C: Implanted hydroxyapatite materials, group D: The control group. All the experimental animals were sacrificed after 2, 4, 8, 12 weeks. Tissue samples were observed by gross observation, radiographic analysis, hematoxylin-eosin (HE) staining, scanning electron microscope (SEM). The value of imaging analysis and osteogenesis were evaluated. The results were analyzed by SPSS 17.0 statistical software. RESULTS: In vivo imaging and histological staining showed that the healing of bone defect and bone quality in group A was significantly better than those in the other groups. SEM showed well biocompatibility between composite material and tissue without inflammation reaction. By measuring and analyzing the dental CT data and new bone area, the bone in group A was obviously better than those in other groups (P < 0.05). CONCLUSION: The extract of Eucommiol can promote ADSCs into bone cells. The role of ADSCs combined with extract of Eucommiol scaffold materials has significant bone induction. It is expected that this material could become a new composite material and be used to fix the jaw bone defects.