Biomimetic porous silk fibroin/biphasic calcium phosphate scaffold for bone tissue regeneration.

The purpose of our study is to prepare a biomimetic porous silk fibroin (SF)/biphasic calcium phosphate (BCP) scaffold, and evaluate its performance in bone tissue regeneration. The differences in pore size, porosity, mechanical strength and biocompatibility of four different fibroin-containing scaffolds (0, 20, 40, and 60% SF) were studied in vitro. After inoculation with MC3T3-E1 cells, the ectopic bone formation ability of the SF/BCP bionic scaffold was evaluated in a rat model. The SEM and CT demonstrated that compared with pure BCP group (0% SF), the pore size and porosity of SF/BCP scaffolds were proportional to SF content, of which 40% of SF and 60% of SF groups were more suitable for cell growth. The compressive strength of SF/BCP scaffold was greater than that of the pure BCP scaffold, and showed a trend of first increasing and then decreasing with the increase of SF content, among which 40% of SF group had the maximum compressive strength (40.80 + 0.68) MPa. The SF/BCP scaffold had good biocompatibility, under the electron microscope, the cells can be smoothly attached to and propagated on the scaffold. After loading the osteoblasts, it showed excellent osteogenic capacity in the rat model. The SF/BCP scaffold can highly simulate the micro-environment of natural bone formation and can meet the requirements of tissue engineering. The SF/BCP biomimetic porous scaffold has excellent physical properties and biocompatibility. It can highly simulate the natural bone matrix composition and microenvironment, and can promote the adhesion and proliferation of osteoblasts. The SF/BCP scaffold has good ectopic osteogenesis after loading with osteoblasts, which can meet the requirements of scaffold materials in tissue engineering, and has broad application prospects in clinical application.

[Observation of lumbar zygapophyseal joints adjacent arterials by anatomy and DSA].

OBJECTIVE: To investigate the arterials adjacent to the lumbar zygapophyseal joints by anatomy and DSA and aimed to provide a safe operation way for the lumbar back and posterolateral surgery by reducing operative hemorrhage in clinical treatment. METHODS: We selected 20 adult corpse lumbar departments and discovered the lumbar lateral artery and lumbar transverse process artery. Using anatomical microscope to observe the lumber transverse process artery and dosal artery of 1-4 lumber arteries from the lumbar spine 1/2-4/5. We also selected 20 patients without lumbar disease and used DSA to research their lumbar arteries and the starting, mutation or branch line of other artery sources in vivo. RESULTS: The anatomy and DSA results showed that the original location of dorsal branch usually at the anterosuperior of L1/2-4/5 foramen intervertebrale outlet area, then distributed to the outside and backside of ZJ. Anterior branch of transverse process sent out and branch into ascending and descending muscle branch. The ascending branch distributed to the below root of upper ZJ and sent out zygapophyseal branches which were distributing to the back of ZJ. The descending branch distributed to the upper root of below ZJ and sent out several muscle branches which were going into muscles in the front. And there were no statistically significant difference between left and right in the body. CONCLUSIONS: The routes of arteries adjacent to ZJ and the relationship between them showed obvious regularity. Mastering its anatomical characteristics could effectively reduce the posterior surgical bleeding, make the operation easier, reduce the important tissue damage and then avoided the postoperative hematoma complications.

A surgical decompression procedure for effective treatment of calcified lumbar disc herniation.

OBJECTIVE: To present our experience in managing calcified lumbar disc herniation (cLDH) using a surgical decompression procedure. METHODS: Patients who had low back pain radiating to the leg, were preoperatively diagnosed with cLDH by computed tomography and/or magnetic resonance imaging, and were treated with a surgical decompression procedure were studied. Those without cLDH or who were treated with a method other than decompression were excluded. The treatment outcome was analyzed using the visual analog scale (VAS) score, Oswestry Disability Index, and modified Macnab criteria. RESULTS: Thirty-seven patients aged 60.5 ± 9.6 years were evaluated. The VAS scores were significantly decreased 1 day after surgery and remained low at the 3-month and 1-year follow-ups. The Oswestry Disability Index was also significantly lower at the 3-month and 1-year follow-ups. Ninety-four percent of patients rated the results as "excellent" or "good" according to the modified Macnab criteria at the 3-month follow-up. The patients developed few postoperative complications and no recurrence during 1 year of follow-up. CONCLUSION: Our data suggest that the decompression approach is effective for management of cLDH at least in the short term (1 year) with respect to reducing pain and improving patient satisfaction with few complications.

Screening of disorders associated with osteosarcoma by integrated network analysis.

Osteosarcoma is a common malignant bone tumor in children and adolescents under the age of 20. However, research on the pathogenesis and treatment of osteosarcoma is still insufficient. In the present study, based on gene-phenotype correlation network, an analysis was performed to screen disorders related to osteosarcoma. First, we analyzed the differential expression of osteosarcoma in two groups according to different types of osteosarcoma and screened the differentially expressed genes (DEGs) related to osteosarcoma. Further, these DEG coexpression modules were obtained. Finally, we identified a series of regulatory factors, such as endogenous genes, transcription factors (TFs), and ncRNAs, which have potential regulatory effects on osteosarcoma, based on the prediction analysis of related network of gene phenotypes. A total of 3767 DEGs of osteosarcoma were identified and clustered them into 20 osteosarcoma-related dysfunction modules. And there were 38 endogenous genes (including ARF1, HSP90AB1, and TUBA1B), 53 TFs (including E2F1, NFKB1, and EGR1), and 858 ncRNAs (including MALAT1, miR-590-3p, and TUG1) were considered as key regulators of osteosarcoma through a series of function enrichment analysis and network analysis. Based on the results of the present study, we can show a new way for biologists and pharmacists to reveal the potential molecular mechanism of osteosarcoma typing, and provide valuable reference for different follow-up treatment options.

Mechanisms responsible for the inhibitory effects of epothilone B on scar formation after spinal cord injury.

Scar formation after spinal cord injury is regarded as an obstacle to axonal regeneration and functional recovery. Epothilone B provides moderate microtubule stabilization and is mainly used for anti-tumor therapy. It also reduces scar tissue formation and promotes axonal regeneration after spinal cord injury. The aim of the present study was to investigate the effect and mechanism of the microtubule-stabilizing reagent epothilone B in decreasing fibrotic scarring through its action on pericytes after spinal cord injury. A rat model of spinal cord injury was established via dorsal complete transection at the T10 vertebra. The rats received an intraperitoneal injection of epothilone B (0.75 mg/kg) at 1 and 15 days post-injury in the epothilone B group or normal saline in the vehicle group. Neuron-glial antigen 2, platelet-derived growth factor receptor ß, and fibronectin protein expression were dramatically lower in the epothilone B group than in the vehicle group, but ß-tubulin protein expression was greater. Glial fibrillary acidic protein at the injury site was not affected by epothilone B treatment. The Basso, Beattie, and Bresnahan locomotor scores were significantly higher in the epothilone B group than in the vehicle group. The results of this study demonstrated that epothilone B reduced the number of pericytes, inhibited extracellular matrix formation, and suppressed scar formation after spinal cord injury.

[Imaging and biomechanics researches of reconstructing lumbosacral stability after L 5 vertebrectomy via anterolateral approach].

Objective: To investigate the feasibility of anterolateral approach for L 5 vertebral resection, bone grafting, and screw rod fixation by imaging and biomechanics researches. Methods: Twenty formalized adult cadavers (12 males and 8 females) were randomly divided into 2 groups; L 5 vertebral resection, bone graft, and screw rod fixation was performed on 10 specimens by using anterolateral approach (experimental group), and on the other 10 specimens by combined anterior and posterior approach. CT scanning and three-dimensional reconstruction were performed in the experimental group; preoperative maximal safe entry angle and depth of screws and intraoperative actual entry angle and depth of screws were measured; the sacral screw position was observed after operation. The biomechanical test was done in 2 groups. Results: Twenty specimens smoothly underwent L 5 excision and reconstruction. CT scan showed that there was no significant difference in maximal safe entry angle and depth of screws between males and females in experimental group before operation ( P>0.05); the maximal safe entry angle and depth were 51.93° and 47.88 mm for anterior screw, and were 37.04° and 46.28 mm for posterior screw. After operation, depth of the sacral anterior and posterior screws were appropriate, which did not pierce into the spinal canal. The biomechanical test results indicated that the flexion, extension, and lateral flexion displacements, and vertical compression stiffness showed no significant difference between 2 groups ( P>0.05). Conclusion: For L 5 lesions not invading posterior column, to use L 5 vertebral resection, bone graft, and screw rod fixation by anterolateral approach is a safe and feasible method to reconstruct lumbosacral stability, with the advantages of no changing posture, less operation time and incision, and prevention of bone graft shift, but effectiveness need further be identified.