Design and preparation of Ti-xFe antibacterial titanium alloys based on micro-area potential difference.

Fe was selected as an alloying element for the first time to prepare a new antibacterial titanium alloy based on micro-area potential difference (MAPD) antibacterial mechanism. The microstructure, the corrosion resistance, the mechanical properties, the antibacterial properties and the cell biocompatibility have been investigated in detail by optical microscopy, scanning electron microscopy, electrochemical testing, mechanical property test, plate count method and cell toxicity measurement. It was demonstrated that heat treatment had a significant on the compressive mechanical properties and the antibacterial properties. Ti-xFe (x = 3,5 and 9) alloys after 850 °C/3 h + 550 °C/62 h heat treatment exhibited strong antimicrobial properties with an antibacterial rate of more than 90% due to the MAPD caused by the redistribution of Fe element during the aging process. In addition, the Fe content and the heat treatment process had a significant influence on the mechanical properties of Ti-xFe alloy but had nearly no effect on the corrosion resistance. All Ti-xFe alloys showed non-toxicity to the MC3T3 cell line in comparison with cp-Ti, indicating that the microzone potential difference had no adverse effect on the corrosion resistance, cell proliferation, adhesion, and spreading. Strong antibacterial properties, good cell compatibility and good corrosion resistance demonstrated that Ti-xFe alloy might be a candidate titanium alloy for medical applications.

Comparative study of outcomes between allograft intervertebral disc transplantation and anterior cervical discectomy and fusion: a retrospective cohort study at least 5 years of follow-up.

PURPOSE: Adjacent segment degeneration (ASDeg) after anterior cervical discectomy and fusion (ACDF) seriously affects the long-term efficacy of the operation. Therefore, our team has done a lot of research on allograft intervertebral disc transplantation (AIDT) to prove its feasibility and safety. This study will compare the efficacy between AIDT and ACDF in the treatment of cervical spondylosis. METHODS: All patients who received ACDF or AIDT in our hospital from 2000 to 2016 and followed up for at least 5 years were recruited and divided into ACDF and AIDT groups. The clinical outcomes including functional scores and radiological data of both groups were collected and compared preoperatively and postoperatively at 1 week, 3 months, 6 months, 12 months, 24 months, 60 months and last follow-up. Functional scores included Japanese Orthopedic Association score (JOA), Neck Disability Index (NDI), Visual Analog Scale of Neck (N-VAS) and Arms (A-VAS) pain, the Short Form Health Survey-36 (SF-36) and imaging dates including digital radiographs in the lateral, hyperextension and flexion positions to assess the stability, sagittal balance and mobility of the cervical spine and magnetic resonance imaging (MRI) scans to assess the degeneration of adjacent segment. RESULTS: There were 68 patients with 25 in AIDT group and 43 in ACDF group. Satisfactory clinical results were obtained in both groups, but the long-term NDI score and N-VAS score in the AIDT group were better. The AIDT obtained the same stability and sagittal balance of the cervical spine as fusion surgery. The range of motion of adjacent segments can be restored to the preoperative level after transplantation, but this increases significantly after ACDF. There were significant differences in the superior adjacent segment range of motion (SROM) between two groups at 12 months (P = 0.039), 24 months (P = 0.035), 60 months (P = 0.039) and the last follow-up (P = 0.011). The inferior adjacent segment range of motion (IROM) and SROM had a similar trend in the two groups. The ratio value of the greyscale (RVG) of adjacent segments showed a downward trend. At the last follow-up, the RVG decreased more significantly in the ACDF group. At the last follow-up, there was a significant difference in the incidence of ASDeg between the two groups (P = 0.000). And the incidence of adjacent segment disease (ASDis) is 22.86% in the ACDF group. CONCLUSION: The allograft intervertebral disc transplantation may be as an alternative technique to traditional anterior cervical discectomy and fusion for the management of cervical degenerative diseases. For the more, the results showed it would improve cervical kinematics and reduce the incidence of adjacent segment degeneration.

Comparison of percutaneous vertebroplasty and conservative treatment for one level thoracolumbar osteoporotic compression fracture in a 3-year study.

The efficacy of Mesh optimized versus standard percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures. Grid optimization (102 cases; 38 men, 64 women aged 67.3 ± 8.5) and traditional PVP groups (94 cases) were identified from 196 PVP patients treated from May 2016 to 2019. The optimal puncture site and angle forced bone cement into both groups before surgery. The main indexes were operation time, X-ray fluoroscopy times, bone cement injection volume, leakage, VAS, and injured vertebrae height. Preoperative general data were equivalent between groups (P > 0.05). All patients survived surgery without spinal cord injury, incision infection, pulmonary embolism, or death. The mesh optimization group had improved operation time (34.8 ± 6.5 min), fluoroscopy times (29.5 ± 5.5), bone cement injection volume (5.3 ± 2.1 ml), and bone cement permeability greater (3.9 percent; 4/98) than the standard PVP group (P < 0.05). Similarly, the grid optimization group had superior VAS scores (1.1 ± 0.6; 1.0 ± 0.3; and 0.9 ± 0.2) than the standard PVP group at 3 days, 3 months, and the last follow-up visit (P < 0.05). On day three after surgery, both had similar heights of injured vertebra's anterior and middle edges (P > 0.05). However, in the mesh optimization group, measurements improved to 1.8 ± 0.4 mm and (1.8 ± 0.3) mm by month three and to 1.7 ± 0.3 mm at last follow-up (P < 0.05). Mesh-optimized PVP with a mesh locator treats osteoporotic vertebral compression fractures more safely and effectively than regular PVP.

Fisetin regulates the biological effects of rat nucleus pulposus mesenchymal stem cells under oxidative stress by sirtuin-1 pathway.

BACKGROUND: Excessive oxidative stress has been accepted as one of the critical factors for intervertebral disc degeneration (IDD), which is associated with low back pain (LBP). Fisetin (Fis) is a bioactive flavonoid that possesses strong bioactive activity. In present study, we aimed to illuminate the role of Fis on nucleus pulposus mesenchymal stem cells (NPMSCs). METHODS: NPMSCs were isolated and cultured from rat NP tissues and identified by flow cytometry and multilinear differentiation. The cytotoxicity of Fis, EX-527, and hydrogen peroxide (H2 O2 ) on NPMSCs was validated using Cell Counting Kit-8 tests. Cell apoptosis was tested by flow cytometry and TUNEL assay. Inflammatory mediators were assessed by Elisa tests, RT-PCR. Extracellular matrix (ECM) metabolism was measured by Western blot analysis and RT-qPCR. The expression of the SIRT1 was evaluated by Western blot analysis. RESULTS: NPMSCs were successfully isolated and cultured from rat NP tissues, and it has been identified by flow cytometry and multilinear differentiation. The results showed that Fis attenuated H2 O2 -induced apoptosis, inflammation, and ECM degradation of NPMSCs. Moreover, the above protective effects of Fis can be inhibited by EX-527, a unique SIRT1 inhibitor, indicating that SIRT1 may involve in the mechanism of Fis in protecting NPMSCs from oxidative stress. CONCLUSIONS: As a natural compound with little cytotoxicity on NPMSCs, Fis alleviate H2 O2 -induced apoptosis, inflammation, and ECM degradation by suppressing oxidative stress, this finding may add the theoretical basis for research on new treatment of IDD based on NPMSCs.

The Inhibitory Effect of RADKPS on Pyroptosis of Nucleus Pulposus-Derived Mesenchymal Stem Cells.

Intervertebral disc (IVD) degeneration (IDD) is a primary cause of low-back pain in people, which is associated with nucleus pulposus-derived mesenchymal stem cells (NPMSCs). In this study, the involvement of lipopolysaccharide (LPS) in the pyroptosis of NPMSCs was investigated. The effect of RADKPS on the pyroptosis of NPMSCs and the underlying mechanism behind the impact of RADKPS on the proliferative capacity of NPMSCs were also studied. Pyroptosis of NPMSCs was induced with 10 µg/mL LPS and its effects on the downstream signaling pathways were explored. The protective effect of RADKPS on NPMSCs under the action of LPS and its possible mechanism were explored, using different techniques such as immunohistochemical analysis, cell proliferation assay, quantitative real-time polymerase chain reaction (qPCR), and Western blot analysis. Accordingly, caspase1/p20/p10, a protein associated with pyroptosis, was found to be overexpressed in LPS-challenged NPMSCs, Furthermore, the qPCR results demonstrated that LPS promoted the expression of pyroptosis-related gene IL-1ß (p < 0.0001), while downregulating the expression of Sox-9 (p < 0.001), which was a gene associated with the extracellular matrix. The immunohistochemical results identified lowered extracellular signal-regulated kinase 1/2 (ERK1/2) expression and phosphorylated (p-)ERK1/2 in the degenerated IVD tissues. In this study, the influence of RADKPS on the proliferative ability of NPMSCs was evaluated using two-dimensional (2D) and three-dimensional (3D) cultures. It was noted that RADKPS promoted the proliferation of NPMSCs in 2D and 3D cultures. The findings of the Western blot experiments revealed that RADKPS inhibited the expression of pyroptosis-related proteins, while it upregulated the p-ERK1/2 (p < 0.001), RhoA (p < 0.01), collagen II (p < 0.01), and Sox-9 (p < 0.01), whereas ERK inhibitor PD98059 and RhoA signaling pathway inhibitor CCG-1423 inhibited their expression. These findings reveal to us that RADKPS hydrogel may protect NPMSCs from pyroptosis. It was also noted that cell proliferation-related signaling pathways may promote the proliferation of NPMSCs. The results revealed that RADKPS hydrogel could be used as a potential therapeutic approach for IDD. Impact Statement RADKPS inhibits the pyroptosis of NPMSCs and promotes the production of extracellular matrix, which has the potential of intervertebral disc biotherapy.

[Research progress of risk factors of adjacent segment degeneration after anterior cervical discectomy and fusion].

Anterior cervical discectomy and fusion (ACDF) has achieved good clinical results since it was used in clinic, and is considered as the gold standard for the treatment of cervical spondylosis. However, more and more attention has been paid to adjacent segment degeneration(ASDeg) after fusion, and the debate about its pathogenesis is mainly focused on the bio-machanical stress changes of adjacent segments caused by fusion and the result of the natural aging process. The occurrence of ASDeg after fusion seriously affect the med-and long-term outcome of surgery, and some patients even need secondary surgery. In order to reduce or even avoid the occurrence of ASDeg, many new techniques have emerged in clinic, such as artificial disc replacement with preservation of motor segments, emerging cell transplantation technology and so on, but the clinical effect still needs to be confirmed by a large number of studies. Therefore, finding the risk factors of ASDeg after fusion is of great significance for fusion surgery on the clinical work. At present, there is still no unified overview of the research on the risk factors of ASDeg. This article will review the research progress and corresponding countermeasures of the risk factors of ASDeg after ACDF, in order to guide the clinical application.

Functionalized self-assembling peptide RADKPS hydrogels promote regenerative repair of degenerated intervertebral discs.

Objective: the aim of this study was to investigate whether the functionalized self-assembling peptide hydrogel RADKPS is safe and effective for regenerative repair of degenerative intervertebral discs. Methods: an in vitro degenerative model of human nucleus pulposus cells was constructed by serum starvation culture, and their proliferation, apoptosis and viability were examined after three-dimensional culture with the RADKPS hydrogel. An in vivo degenerative model of the rabbit intervertebral disc was constructed by annulus fibrosus puncture, and the degeneration of the intervertebral disc was evaluated by imaging, histology, immunohistochemistry, and biomechanics after RADKPS hydrogel intervention. Results: through in vitro cell experiments it is shown that human degenerated nucleus pulposus cells after three-dimensional culture with the RADKPS hydrogel still exhibited better proliferation, viability, and low apoptosis rate. Through in vivo animal experiments we found that rabbit degenerated intervertebral discs intervened with the RADKPS hydrogel had higher water content, better histological morphology, more extracellular matrix synthesis, and better biomechanical properties. It is demonstrated that the RADKPS hydrogel may initiate the endogenous repair process through the sustained recruitment and enrichment of nucleus pulposus progenitor cells. Conclusion: it is verified from both in vitro cellular experiments and in vivo animal experiments that the regenerative repair effect of RADKPS, a functionalized self-assembling peptide hydrogel, on degenerated intervertebral discs is safe and effective. It is shown that it would be a new therapeutic approach for the regenerative repair action of intervertebral discs.

MCP­1/CCR2 axis inhibits the chondrogenic differentiation of human nucleus pulposus mesenchymal stem cells.

Intervertebral disc degeneration (IDD) creates a hostile environment with high osmotic pressure, high mechanical stress, hypoxia and a low pH, where cytokines such as TNF­α and IL­1ß are highly expressed. The degenerating intervertebral disc has high local expression of monocyte chemoattractant protein­1 (MCP­1), which is associated with the degree of degeneration. However, there are a few reports on the influence of MCP­1 on nucleus pulposus­derived stem cells (NPSCs). In the present study, a significant upregulation of MCP­1 was observed in NPSCs cultured in vitro with pro­inflammatory cytokines. MCP­1 significantly inhibited the migration and proliferation of NPSCs in a dose­dependent manner as detected via Cell Counting Kit­8, wound healing and Transwell assays. Western blotting and histological analysis demonstrated that MCP­1 significantly reduced chondrogenic NPSC differentiation. Reverse transcription­quantitative PCR and western blotting revealed that C­C chemokine receptor type 2 (CCR2) mRNA and protein expression levels were significantly enhanced by MCP­1. Furthermore, MCP­1 significantly inhibited the migration, differentiation and proliferation of NPSCs, which was effectively reversed by blocking CCR2 with the inhibitor RS504393. Overall, these results demonstrated that MCP­1 may contribute to the inhibition of chondrogenic NPSC differentiation via MCP­1/CCR2 chemotaxis signals, providing a potential therapeutic target for IDD.

Intradiscal Injection of Autologous Discogenic Cells in Patients with Discectomy: A Prospective Clinical Study of Its Safety and Feasibility.

The treatment of intervertebral disc degeneration (IVDD) is still a huge challenge for clinical updated surgical techniques and basic strategies of intervertebral disc regeneration. Few studies have ever tried to combine surgery and cell therapy to bridge the gap between clinical and basic research. A prospective clinical study with a 72-month follow-up was conducted to assess the safety and feasibility of autologous discogenic cells transplantation combined with discectomy in the treatment of lumbar disc herniation (LDH) and to evaluate the regenerative ability of discogenic cells in IVDD. Forty patients with LDH who were scheduled to have discectomy enrolled in our study and were divided into the observed group (transplantation of autologous discogenic cells after discectomy) and control group (only-discectomy). Serial MRI and X-ray were used to evaluate the degenerative extent of index discs, and clinical scores were used to determine the symptomatic improvement. No adverse events were observed in the observed group, and seven patients in the control group underwent revisions. Both groups had significant improvement of all functional scores post-operatively, with the observed group improving more considerably at 36-month and 72-month follow-up. The height and water content of discs in both groups decreased significantly since 36 months post-op with the control group decreased more obviously. Discectomy combined with autologous discogenic cells transplantation is safe and feasible in the treatment of LDH. Radiological analysis demonstrated that discogenic cells transplantation could slow down the further degeneration of index discs and decrease the complications of discectomy.

[Combining K-line to analyse the relationship between cervical range of motion of patients with ossification of cervical posterior longitudinal ligament and surgical prognosis].

OBJECTIVE: Combining K-line (the connecting line of the midpoint of C2 and C7 spinal canal on the cervical lateral X-ray film) to analyze the relationship between cervical range of motion of patients with ossification of posterior longitudinal ligament (OPLL) and surgical prognosis. METHODS: A total 42 patients with ossification of cervical posterior longitudinal ligament underwent cervical posterior single open-door laminoplasty between April 2014 and March 2017 were retrospectively ananyzed. The patients were dividing into K-line (+) group and K-line (-) group according to the position realationship of OPLL and K-line. The lesion of ossification of the posterior longitudinal ligament was not over than the K-line known as K-line (+). Conversely, the lesion of ossification of the posterior longitudinal ligament crossing the K-line was called K-line (-). Preoperative and postoperative 3 months JOA scores were observed, and postoperative 3 months JOA improvement rate were computed to assess patient's neurological function recovery. Preoperation and postoperative 3 months, OPLL occupation ratio (OOR), cervical lordotic angles (CLA) and cervical lordotic value (CLV) were measured respectively. The realationship between postoperative neurologic functional recovery in patients of CLV>0 group and CLV<=0 group was evaluated in different K-line subgroups. RESULTS: For the patients in K (+) group and K (-) group, preoperative CLA were (14.7±9.6)° and (-6.4±9.5)°(P<0.05) respectively, postoperative at 3 months CLA were (14.0±8.0)° and (-1.4±10.4)°(P<0.05) respectively; preoperative JOA scores were 10.9±3.2 and 11.2±2.5 (P>0.05) respectively, postoperative at 3 months JOA scores were 14.2±1.8 and 12.6±2.2 (P<0.05) respectively, and postoperative at 3 months JOA score improvement rate were (54.7±17.6)% and (25.5±15.7)%(P<0.05) respectively. In the K-line (+) group, there were 29 patients in CLV>0 group at 3 months after operation, with improvement rate of (52.3±17.2)%, and 4 patients in CLV<=0 group, with improvement rate of (72.2±7.8)%. The improvement rate of the patients in CLV<=0 group was significantly better than that of the patients in CLV>0 group (P<0.05). CONCLUSIONS: No matter whether the ossification of cervical posterior longitudinal ligament was classified as K-line (+) or K-line (-), the cervical posterior single open-door laminoplasty can improve the neurological symptoms of patients, especially the patients in the K-line(+) group with better prognosis. The patinets in K-line(+) group, when postoperative at 3 months CLV>0, their improvement rate was lower than that of the patients with postoperative at 3 months CLV<=0.