Objective: To investigate the bone repair and regeneration ability of biomimetic mineralized collagen bone graft material and autologous bone marrow in rabbit posterolateral spinal fusion model. Methods: Twenty-seven 20-week-old male New Zealand white rabbits ［weighing (5.0±0.5) kg］ were used to establish the posterolateral spinal fusion model of L 5 and L 6 segments by stripping the transverse process and exposing cancellous bone with electric burr. The rabbits were randomly divided into 3 groups, 9 in each group. Groups A, B, and C were implanted 1.5 mL autologous iliac bone, 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material, and 1.5 mL (30 mm×10 mm×5 mm) biomimetic mineralized collagen bone graft material and autologous bone marrow in each bone defect. At 4, 8, and 12 weeks after operation, the apparent hardness of the bone grafting area was observed by manipulation method, in order to evaluate bone graft fusion effects. Three animals were sacrificed in each group at each time point, the vertebral body specimens were excised and the bone defect repair and fusion were observed by X-ray films, and three-dimensional CT examination was performed to evaluate whether new bone was formed in the body. HE staining was performed at each time point to observe the formation of new bone and the repair and fusion of bone defects. Results: The manipulation test showed that bone graft fusion was not found in all groups at 4 weeks after operation; 3 (50.0%), 2 (33.3%), and 4 (66.7%) of groups A, B, and C reached bone graft fusion at 8 weeks after operation; 5 (83.3%), 4 (66.7%), and 5 (83.3%) of groups A, B, and C reached bone graft fusion at 12 weeks after operation; the fusion rate of group C was similar to that of group A, and all higher than that of group B. X-ray film observation showed that the fusion rate of group C at 8 and 12 weeks after operation was higher than that of group B, similar to group A. Three-dimensional CT observation showed that the effect of bone fusion in group C was better than that in group B, which was close to group A. HE staining observation showed that large area of mature lamellar bone coverage appeared in the bone graft area of groups A, B, and C at 12 weeks after operation, the material was completely degraded, and the marginal boundary of the host bone disappeared and tightly combined. Conclusion: Biomimetic mineralized collagen bone graft material mixed with autologous bone marrow has good osteoinduction and osteogenesis guidance. Compared with biomimetic mineralized collagen bone graft material, it has better and faster osteogenesis effect, which is close to autologous bone transplantation.

Objective:To study the effects of beta tricalcium phosphate(β-TCP)/collagen scaffold loaded with human bone morphogenetic protein 2 (hBMP2) plasmid on the osteogenesis ability of MC3T3-E1 cells.Methods:hBMP2 DNA plasmid-modified β-TCP/collagen scaffold and the naked plasmid(control) were constructed.MC3T3-E1 cells were respectively in vitro cultured onto the β-TCP/collagen scaffold with hBMP2(Z) and with control plasmid(Z0),on peace dish with the saffold and hBMP2(M) and with the control plasmid(M0).The surface morphology of the samples was observed by SEM.Osteogenesis of the cells was examined by alkaline phosphatase activity(ALP) test,real-time fluorescent quantitative PCR for the detection of Runx2,OCN,ALP and OPN mRNA expression.Data were statistically analyzed.Results:The composite sample surface of plasmid DNA containing hBMP2 modified β-TCP/collagen was porous;group Z and M showed highter ALP activity and higher mRNA expression of Runx2,OCN,ALP and OPN than group Z0 and M0;so did group Z than group M.Conclusion:Porous β-TCP/collagen scaffold loaded with BMP2 DNA is potential for osteoinduction.

Objective:To analyze the brain function of patients with delirium in intensive care unit (ICU) using resting-state functional magnetic resonance imaging (fMRI), further analyze the structural changes in the brain using diffusion tensor imaging (DTI), and explore the correlations of brain function with structural changes in patients with delirium in ICU from a new perspective of functional imaging, provide visual evidence for the diagnosis of delirium.Methods:Patients with delirium admitted to ICU of the Affiliated Hospital of Zunyi Medical University from January 1st to December 31st in 2017 were enrolled as subjects. During the same period, the healthy volunteers who matched the gender, age and education level of the patients with delirium were enrolled as control group. The intensive care delirium screening checklist (ICDSC) scores within 24 hours after ICU admission were recorded. All the subjects were scanned by fMRI and DTI. The abnormal changes in resting-state brain function of the patients with delirium were evaluated by cerebral regional homogeneity (ReHo) data analysis. The DTI data were processed by the FSL software, and the fractional anisotropy (FA) and mean diffusivity (MD) of the brain were extracted, respectively, to evaluate the damage to brain structure. The values of ReHo, FA and MD were compared between the two groups. The ReHo value of brain region with reduced ReHo value of patients with delirium as compared with the healthy volunteers was extracted for Pearson correlation analysis with ICDSC scores.Results:A total of 22 patients with delirium were included. Seven patients who did not cooperate in the examination, used sedatives or had false images in scanning, were excluded. Finally, 15 patients were enrolled in the delirium group, and 15 healthy volunteers in the healthy control group. ① No statistically significant difference was found in gender, age or education time between the two groups. ICDSC score of the delirium group was significantly higher than that of the healthy control group (6.07±1.28 vs. 1.07±0.88, P < 0.01). ② fMRI scanning and analysis results: compared with the healthy control group, the ReHo values of the cerebellum, right hippocampus, striatum, midbrain and pons in the delirium group were significantly increased (all P < 0.05, AlphaSim correction), while the ReHo values of bilateral superior frontal gyrus, bilateral median frontal gyrus, left inferior frontal gyrus, temporal lobe and parietal lobe were significantly lowered (all P < 0.05, AlphaSim correction). Correlation analysis showed that the ReHo value of the left superior frontal gyrus was negatively correlated with ICDSC score in the patients with delirium ( r = -0.794, P < 0.05), indicating that the changes in the functional area of the medial frontal gyrus was most closely related to delirium. ③ DTI scanning and analysis results: compared with the healthy control group, the FA values of the left cerebellum, bilateral frontal lobes, left temporal lobe, corpus callosum and left hippocampus in the delirium group were decreased significantly (all P < 0.05, AlphaSim correction), while the MD values of the medial frontal gyrus, right superior temporal gyrus, anterior cingulate gyrus, bilateral insular lobes and left caudate nucleus were enhanced significantly (all P < 0.05, AlphaSim correction), suggesting that the structural and functional damage was found in multiple brain regions in patients with delirium. Conclusions:Multiple brain regions of patients with delirium present abnormal resting-state brain function. The abnormal resting-state brain function of the left superior frontal gyrus is closely related to the occurrence of delirium. Structural damage is found in multiple brain regions of patients with delirium. The structural changes in the frontal lobe, temporal lobe, corpus callosum, hippocampus and cerebellum and their abnormal functions can be used as preliminary imaging indexes for the diagnosis of delirium.