Comparison of the clinical outcomes of VBE-TLIF versus MIS-TLIF for single-level degenerative lumbar diseases.

OBJECTIVE: This research aims to compare the clinical outcomes of VBE-TLIF and MIS-TLIF for the treatment of patients with single-level degenerative lumbar diseases. METHODS: Ninety patients were enrolled in this study. The estimated blood loss, operation time, postoperative hospitalization days, time to functional exercise, amount of surgical drain and inflammatory index were recorded. The visual analog scale, Oswestry dysfunction index and modified MacNab criteria were used to assessed the patient's back and leg pain, functional status and clinical satisfaction rates. RESULTS: The average operation time of the VBE-TLIF group was longer than that of the MIS-TLIF group. The time for functional exercise, length of hospital stay, estimated blood loss and amount of surgical drain in the VBE-TLIF group were relative shorter than those in the MIS-TLIF group. Additionally, the levels of CRP, neutrophil, IL-6 and CPK in the VBE-TLIF group were significantly lower than those in the MIS-TLIF group at postoperative days 1 and 3, respectively (P < 0.001). Patients undergoing VBE-TLIF had significantly lower back VAS scores than those in the MIS-TLIF group on postoperative days 1 and 3 (P < 0.001). No significant differences were found in the clinical satisfaction rates (95.83 vs. 95.24%, P = 0.458) or interbody fusion rate (97.92 vs. 95.24%, P = 0.730) between these two surgical procedures. CONCLUSIONS: Both VBE-TLIF and MIS-TLIF are safe and effective surgical procedures for patients with lumbar diseases, but VBE-TLIF technique is a preferred surgical procedure with merits of reduced surgical trauma and quicker recovery.

Clinical Outcomes of Percutaneous Transforaminal Endoscopic Discectomy Assisted with Selective Nerve Root Block for Treating Radicular Pain with Diagnostic Uncertainty in the Elderly.

Purpose: To investigate the clinical outcomes of percutaneous transforaminal endoscopic discectomy assisted with selective nerve root block for treating radicular pain with diagnostic uncertainty in the elderly. Methods: A total number of 36 elderly patients were included in the study. Clinical outcomes collected for analysis include operative time, hospital stay time, Visual Analog Scale, and Oswestry Disability Index before and after the surgery, the global outcome based on the Macnab outcome criteria. Results: Seventeen males and nineteen females with a mean age of 73.72 ± 7.15 were included in this study. Radicular pain was the main complaint of all the patients with the least symptom duration of two months. Radiological findings showed that 80.6% of the patients with multilevel disc herniation, 16.7% received lumbar fusion surgery before, and 8.3% with degenerative scoliosis. Besides, 69.4% of the patients have at least one comorbidity. 85.4% of the patients showed a positive response to selective nerve root block, and 91.6% of the patients reported a favorable outcome at the last follow-up. The mean value of pre-operative leg pain was 7.56 ± 0.74 and dramatically decreased after surgery (2.47 ± 0.81, P < 0.001). Besides, the mean value of Oswestry Disability Index decreased from 43.03 ± 4.43 to 5.92 ± 5.24 (P < 0.001) one year after the surgery. Conclusion: Multilevel degeneration of the lumbar spine is common in elderly patients. Identifying the responsible segment and decompressing the nerve root through minimally invasive surgery can provide a satisfactory clinical outcome for those with radicular pain as their primary complaint. And selective nerve root block is a reliable diagnostic tool for those with an ambiguous diagnosis.

Mapping the hotspots and future trends of electrical stimulation for peripheral nerve injury: A bibliometric analysis from 2002 to 2023.

Peripheral nerve injuries often result in severe personal and social burden, and even with surgical treatment, patients continue to have poor clinical outcomes. Over the past two decades, electrical stimulation has been shown to promote axonal regeneration and alleviate refractory neuropathic pain. The aim of this study was to analyse this field using a bibliometric approach. Literature was searched through Web of Science Core Collection (WOSCC) for the years 2002-2023. Literature analysis included: (1) Describing publication trends in the field. (2) Exploring collaborative network relationships. (3) Finding research advances and research hotspots in the field. (4) Summarizing research trends in the field. With the number of studies in this field still increasing, a total of 693 publications were included in the analysis. This field of research is interdisciplinary in nature. Research hotspots include peripheral nerve regeneration, the treatment of neuropathic pain, materials for nerve injury repair, and the restoration of sensory function in patients with peripheral nerve injury. Correspondingly, the development of nerve conduits and systems for peripheral nerve electrical stimulation, clinical trials of peripheral nerve electrical stimulation, and tactile recovery and movement for amputees have shown significant promise as future research trends in this field.

Amorphous 1-D nanowires of calcium phosphate/pyrophosphate: A demonstration of oriented self-growth of amorphous minerals.

Amorphous inorganic solids are traditionally isotropic, thus, it is believed that they only grow in a non-preferential way without the assistance of regulators, leading to the morphologies of nanospheres or irregular aggregates of nanoparticles. However, in the presence of (ortho)phosphate (Pi) and pyrophosphate ions (PPi) which have synergistic roles in biomineralization, the highly elongated amorphous nanowires (denoted ACPPNs) form in a regulator-free aqueous solution (without templates, additives, organics, etc). Based on thorough characterization and tracking of the formation process (e.g., Cryo-TEM, spherical aberration correction high resolution TEM, solid state NMR, high energy resolution monochromated STEM-EELS), the microstructure and its preferential growth behavior are elucidated. In ACPPNs, amorphous calcium orthophosphate and amorphous calcium pyrophosphate are distributed at separated but close sites. The ACPPNs grow via either the preferential attachment of ∼2 nm nanoclusters in a 1-dimension way, or the transformation of bigger nanoparticles, indicating an inherent driving force-governed process. We propose that the anisotropy of ACPPNs microstructure, which is corroborated experimentally, causes their oriented growth. This study proves that, unlike the conventional view, amorphous minerals can form via oriented growth without external regulation, demonstrating a novel insight into the structures and growth behaviors of amorphous minerals.

Global Scientific Trends in Virtual Reality for Pain Treatment From 2000 to 2022: Bibliometric Analysis.

Background: Virtual reality (VR) is a computer simulation technique that has been increasingly applied in pain management over the past 2 decades. Objective: In this study, we used bibliometrics to explore the literature on VR and pain control, with the aim of identifying research progress and predicting future research hot spots. Methods: We extracted literature on VR and pain control published between 2000 and 2022 from the Web of Science Core Collections and conducted bibliometric analyses. We analyzed the publication and citation trends in the past 2 decades, as well as publication and citation analyses of different countries, institutions, journals, and authors. For references, we conducted cocitation and burst analyses. For keywords, we conducted co-occurrence, clustering, timeline view, and citation burst analyses. Results: Based on 1176 publications, we found that there was a continuous increase in publication and citation volumes, especially in the last 5 years. The United States was the most representative country, and the University of Washington was the most representative institution, with both having the most publications and citations. The most popular journal in this field was Burns, and Hoffman HG was the most productive author, leading many studies on patients with burn pain. The reference with the most citation burst was a study on the verification of new hardware in pain control. The keywords with the highest citation bursts related to various situations of pain such as "burn pain," "wound care," "low back pain," and "phantom limb." Conclusions: VR has been applied in various clinical situations for pain management, among which burns and pediatric surgery have achieved satisfactory results. We infer that VR will be extended to more clinical pain situations in the future, such as pain control in wound care, low back pain, and phantom limb pain. New research hot spots will include the development of software and hardware to improve the immersive experience of VR for pain control. However, our work was based solely on English literature from the Web of Science database. For future studies, we recommend that researchers explore literature from multiple databases to enhance the scope of their research.

Research hotspots and trends on spinal cord stimulation for pain treatment: a two-decade bibliometric analysis.

Background: Chronic pain poses a significant social burden. Spinal cord stimulation (SCS) is considered to be the most promising treatment for refractory pain. The aim of this study was to summarize the current research hotspots on SCS for pain treatment during the past two decades and to predict the future research trends by bibliometric analysis. Methods: The literature over the last two decades (2002-2022) which was related to SCS in pain treatment was obtained from the Web of Science Core Collection. Bibliometric analyses were conducted based on the following aspects: (1) Annual publication and citation trends; (2) Annual publication changes of different publication types; (3) Publications and citations/co-citations of different country/institution/journal/author; (4) Citations/co-citation and citation burst analysis of different literature; and (5) Co-occurrence, cluster, thematic map, trend topics, and citation burst analysis of different keywords. (6) Comparison between the United States and Europe. All analyses were performed on CiteSpace, VOSviewer, and R bibliometrix package. Results: A total of 1,392 articles were included in this study, with an increasing number of publications and citations year by year. The most highly published type of literature was clinical trial. United States was the country with the most publications and citations; Johns Hopkins University was the institution with the most publications; NEUROMODULATION published the most papers; the most published author was Linderoth B; and the most cited paper was published in the PAIN by Kumar K in 2007. The most frequently occurring keywords were "spinal cord stimulation," "neuropathic pain," and "chronic pain," etc. Conclusion: The positive effect of SCS on pain treatment has continued to arouse the enthusiasm of researchers in this field. Future research should focus on the development of new technologies, innovative applications, and clinical trials for SCS. This study might facilitate researchers to comprehensively understand the overall perspective, research hotspots, and future development trends in this field, as well as seek collaboration with other researchers.

Minimally invasive transforaminal lumbar interbody fusion by a novel two-medium compatible bichannel endoscopy system, technique note and preliminary clinical results.

PURPOSE: Our team designed a novel two-medium compatible bichannel endoscopy system for spinal surgery, V-shape bichannel endoscopy (VBE) system. Hereby, this study will introduce minimally invasive transforaminal lumbar interbody fusion (TLIF) with VBE system and report its preliminary clinical results. METHODS: Fifty-two participants, who accepted VBE-assisted TLIF surgery (VBE-TLIF) in our hospital were included in this study. The duration of operation, off-bed time, and days of hospitalization were recorded. Besides, the patient's preoperative and postoperative pain were evaluated via visual analog scale (VAS), the functional status was evaluated via Oswestry dysfunction index (ODI) and modified MacNab criteria. Patients were asked to follow-up in the outpatient department at the 3rd, 6th, 12th, and 24th month after surgery. X-ray or CT was examined to evaluate the internal fixation position and interbody fusion result. RESULTS: All patients received unilateral decompression with an average operation duration of 178.49 ± 27.49 min. After the surgery, their VAS score of leg pain and back pain reduced significantly. At the last follow-up, the VAS score of leg pain and back pain was 0.80 ± 0.69 and 0.86 ± 0.75 separately. The difference shows statistically significant with p < 0.05. At the last follow-up, the ODI was 15.20 ± 5.75. According to modified MacNab criteria, 39 patients rated their function as excellent, and 10 patients were good. The overall satisfaction rate reached 94%. CONCLUSION: The VBE system reported in the current study can complete TLIF surgery safely and effectively.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up.

BACKGROUND CONTEXT: Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSE: To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGN: Prospective, multicenter, international, observational cohort study. PATIENT SAMPLE: Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURES: Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODS: Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTS: Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONS: Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Novel Nomograms and Web-Based Tools Predicting Overall Survival and Cancer-specific Survival of Solitary Plasmacytoma of the Spine.

STUDY DESIGN: Retrospective analysis. OBJECTIVE: This study aimed to establish nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) in patients with solitary plasmacytoma of the spine (SPS). SUMMARY OF BACKGROUND DATA: SPS is a rare type of malignant spinal tumor. A systematic study of prognostic factors associated with survival can provide guidance to clinicians and patients. Consideration of other causes of death (OCOD) in CSS will improve clinical practicability. METHODS: A total of 1078 patients extracted from the SEER database between 2000 and 2018 were analyzed. Patients were grouped into training and testing data sets (7:3). Factors associated with OS and CSS were identified by Cox regression and competing risk regression, respectively, for the establishment of nomograms on a training data set. The testing data set was used for the external validation of the performance of the nomograms using calibration curves, Brier's scores, C-indexes, time-dependent receiver operating characteristic curves, and decision curve analysis (DCA). RESULTS: Age and grade were identified as factors associated with both OS and CSS, along with marital status, radiation for OS, and chemotherapy for CSS. Heart disease, cerebrovascular disease, and diabetes mellitus were found to be the 3 most common causes of OCOD. The nomograms showed satisfactory agreement on calibration plots for both training and testing data sets. Integrated Brier score, C-index, and overall area under the curve on the testing data set were 0.162/0.717/0.789 and 0.173/0.709/0.756 for OS and CSS, respectively. DCA curves showed a good clinical net benefit. Nomogram-based web tools were developed for clinical application. CONCLUSION: This study provides evidence for risk factors and prognostication of survival in SPS patients. The novel nomograms and web-based tools we developed demonstrated good performance and might serve as accessory tools for clinical decision-making and SPS management. LEVEL OF EVIDENCE: 3.

Web-Based Nomograms for Overall Survival and Cancer-Specific Survival of Bladder Cancer Patients with Bone Metastasis: A Retrospective Cohort Study from SEER Database.

BACKGROUND: Our study aimed to explore the prognostic factors of bladder cancer with bone metastasis (BCBM) and develop prediction models to predict the overall survival (OS) and cancer-specific survival (CSS) of BCBM patients. METHODS: A total of 1438 patients with BCBM were obtained from the SEER database. Patients from 2010 to 2016 were randomly divided into training and validation datasets (7:3), while patients from 2017 were divided for external testing. Nomograms were established using prognostic factors identified through Cox regression analyses and validated internally and externally. The concordance index (C-index), calibration plots, and time-dependent receiver operating characteristic (ROC) curves were used to evaluate the discrimination and calibration of nomogram models, while decision curve analyses (DCA) and Kaplan-Meier (KM) curves were used to estimate the clinical applicability. RESULTS: Marital status, tumor metastasis (brain, liver, and lung), primary site surgery, and chemotherapy were indicated as independent prognostic factors for OS and CSS. Calibration plots and the overall C-index showed a novel agreement between the observed and predicted outcomes. Nomograms revealed significant advantages in OS and CSS predictions. AUCs for internal and external validation were listed as follows: for OS, 3-month AUCs were 0.853 and 0.849; 6-month AUCs were 0.873 and 0.832; 12-month AUCs were 0.825 and 0.805; for CSS, 3-month AUCs were 0.849 and 0.847; 6-month AUCs were 0.870 and 0.824; 12-month AUCs were 0.815 and 0.797, respectively. DCA curves demonstrated good clinical benefit, and KM curves showed distinct stratification performance. CONCLUSION: The nomograms as web-based tools were proved to be accurate, efficient, and clinically beneficial, which might help in patient management and clinical decision-making for BCBM patients.

A polypeptide coating for preventing biofilm on implants by inhibiting antibiotic resistance genes.

Aging population has been boosting the need for orthopedic implants. However, biofilm has been a major obstacle for orthopedic implants due to its insensitivity to antibiotics and tendency to drive antimicrobial resistance. Herein, an antibacterial polypeptide coating with excellent in vivo adhesive capacity was prepared to prevent implants from forming biofilms and inducing acquired antibiotic resistance. A peptide-based copolymer, poly[phenylalanine10-stat-lysine12]-block-3,4-dihydroxy-l-phenylalanine [Poly(Phe10-stat-Lys12)-DOPA] was modularly designed, where poly(Phe10-stat-Lys12) is antibacterial polypeptide with high antibacterial activity, and DOPA provides strong adhesion in both wet and dry microenvironments. Meanwhile, compared to traditional "graft-onto" methods, this antibacterial coating can be facilely achieved by immersing Titanium substrates into antibacterial polypeptide solution for 5 min at room temperature. The poly(Phe10-stat-Lys12)-DOPA polymer showed good antibacterial activity with minimum inhibitory concentrations against S. aureus and E. coli of 32 and 400 µg/mL, respectively. Compared to obvious antimicrobial resistance of S. aureus after continuous treatment with vancomycin, this antibacterial coating doesn't drive antimicrobial resistance upon long-term utilization. Transcriptome sequencing and qPCR tests further confirmed that the antibacterial coating was able to inhibit the expression of multiple peptide resistance factor (mprF) and lipoteichoic acid modification D-alanylation genes (dltB and dltC) that can increase the net positive charge of bacterial cell wall to induce the resistance to cationic antimicrobial peptides. In vivo experiments confirmed that this poly(Phe10-stat-Lys12)-DOPA coating can both effectively prevent biofilm formation through surface contact sterilization and avoid local and systemic infections. Overall, we proposed a facile method for preparing antibacterial orthopedic implants with longer indwelling time and without inducing antimicrobial resistance by coating a polypeptide-based polymer on the implants.

Sagittal alignment of the cervical spine: radiographic analysis of 111 asymptomatic adolescents, a retrospective observational study.

PURPOSE: To describe the cervical spine morphology and explore its relationship to global sagittal alignment parameters in the asymptomatic adolescent population.  METHODS: A total of 111 adolescent subjects were included. Sagittal alignment parameters, including C7 Slope, C2-C7 Cobb, C2-7 plumb line (PL), C2-S1 Sagittal Vertical Axis (SVA), C7-S1 SVA, T5-12 Cobb, T10-L2 Cobb, L1-S1 Cobb, pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS), were obtained from lateral radiographs.  RESULTS: Forty-four males and sixty-seven females with a mean age of 16.12 ± 2.40 years were included in this study. The mean values of C7 Slope, C2-7 Cobb and C2-7PL were 20.45 ± 8.88°, -7.72 ± 12.10°, and 13.53 ± 11.63 mm, respectively. C2-7 Cobb, C7 Slope showed significant differences between the male and female groups. Correlation analysis showed that C7 slope was significantly correlated with C2-7 Cobb (r = -0.544, P < 0.001), C2-S1 SVA (r = 0.335, P < 0.001), and C7-S1 SVA (r = 0.310, P = 0.001), but not lumbosacral parameters(L5-S1 Cobb, PI, PT, SS). Using a modified method of Toyama to describe the cervical spine morphology, there were 37 cases (33.3%) in the Lordotic group, and C7 slope, C2-7 Cobb and C2-7PL showed significant differences between groups. According to C2-C7 Cobb, there were 80 Lordotic cases (72.1%). C7 slope and C2-7PL were significantly different between the two groups. CONCLUSION: The cervical spine morphology of asymptomatic adolescents varies widely, from lordotic to kyphotic. Combining different classification methods provides a better understanding of the morphology of the cervical spine. C7 slope is an important predictor of global sagittal balance and C2-7PL is a key parameter for restoring cervical lordosis, which should be considered pre-operatively and for conservative treatment. Cervical regional sagittal alignment parameters are not correlated with lumbosacral parameters, and C2-7 Cobb, C7 Slope showed significant differences between males and females.

Mineralized Enzyme-Based Biomaterials with Superior Bioactivities for Bone Regeneration.

The formation and metabolic balance of bone tissue is a controllable process of biomineralization, which is regulated by various cells, biomolecules, and ions. Enzyme molecules play an important role in this process, and alkaline phosphatase (ALP) is one of the most critical factors. In this study, inspired by the process of bone biomineralization, a biomimetic strategy is achieved for the preparation of mineralized ALP nanoparticles (MALPNs), by taking advantages of the unique reaction between ALP and calcium ions in Dulbecco's modified Eagle's medium. Benefiting from the mild biomineralization reaction, the MALPN system highly maintains the activity of ALP. Furthermore, the in vitro studies show that the MALPN system significantly enhances the proliferation of bone marrow mesenchymal stem cells and upregulates their osteogenic differentiation. When evaluated as synthetic graft materials for bone regeneration, the MALPN-incorporated gelatin methacryloyl graft shows excellent mechanical properties, a sustained release profile of ALP, and high biocompatibility and efficacy in guiding bone regeneration and vascularization for critical-sized rat calvarial defect. Moreover, we also demonstrate that the biomimetic mineralization strategy can be adopted for other proteins such as acid phosphatase, bovine serum albumin, fibrinogen, and gelatin, suggesting its universality for constructing mineralized protein-/enzyme-based bioactive materials for the application of tissue regeneration.

Biomechanical analysis of atlantoaxial intraarticular fusion cages with posterior pedicle screws fixation using finite element method.

BACKGROUND: Cadaveric biomechanical studies indicated that atlantoaxial intraarticular fusion cages with posterior pedicle screws fixation could increase the multi-axial rigidity. However, the stress distribution of the fixation construct is still unclear. METHODS: From computed tomography images, a nonlinear intact three-dimensional C0-2 finite element model was developed and validated. Four finite element models were reconstructed: intact model, unstable model, bilateral atlantoaxial pedicle screws combined bilateral cages model, bilateral atlantoaxial pedicle screws model. The range of motion and maximum von Mises stresses were compared under flexion, extension, lateral bending, and axial rotation. FINDINGS: Compared with unstable model, both bilateral atlantoaxial pedicle screws combined bilateral cages model and bilateral atlantoaxial pedicle screws model fixation techniques reduced range of motion by >99% in extension, flexion, lateral bending and axial rotation. For bilateral atlantoaxial pedicle screws combined bilateral cages model, the maximum von Mises stress was in the base of the C2 screw head site. In the bilateral atlantoaxial pedicle screws model was stressed at the rod linked C1 and C2 screws. Compared with bilateral atlantoaxial pedicle screws model, bilateral atlantoaxial pedicle screws combined bilateral cages model reduced the maximum von Mises stress on the implants by >90% in extension, flexion, lateral bending and axial rotation. INTERPRETATION: The finite element model study indicated that, compared with posterior C1-C2 pedicle screws fixation, atlantoaxial intraarticular fusion cages with posterior pedicle screws fixation could not only significantly restore stability to the atlantoaxial junction, but also dramatically reduce the maximum von Mises stress in the C1-C2 pedicle screws.

Excessive mechanical stress-induced intervertebral disc degeneration is related to Piezo1 overexpression triggering the imbalance of autophagy/apoptosis in human nucleus pulpous.

BACKGROUND: Mechanical stress plays a crucial role in the pathogenesis of intervertebral disc degeneration (IVDD). The mechanosensitive Piezo1 ion channel can sense the changes in mechanical stress and convert the mechanical signals into chemical signals. This study aims to investigate the effect of Piezo1 on the mechanical stress-induced IVDD and explore the possible mechanism. METHODS: The expression of Piezo1 and collagen II in immunohistochemical staining, cervical curvature, and the stiffness of nucleus pulpous (NP) were performed in normal and degenerated human intervertebral discs. In the experiment, high-intensity compression was applied to mimic the mechanical environment of IVDD. The cell viability, matrix macromolecules, and pro-inflammatory cytokines were examined to investigate the effect of Piezo1 on mechanical stress-treated NP cells. Additionally, autophagy condition of NP cells was detected within high-intensity compression and/or the inhibitor of Piezo1, GsMTx4. RESULTS: The up-expression of Piezo1, down-expression of Col II, elevated stiffness of NP, and poor kyphosis were observed in degenerated human intervertebral discs. High-intensity stress significantly decreased cell viability and the synthesis of extracellular matrix but increased the expression of senescence-associated proteins (p53 and p16) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) by mitochondrial dysfunction and suppression of autophagy. However, GsMTx4 can partly attenuate these effects. CONCLUSION: Piezo1 upregulation under excessive mechanical stress promotes the apoptosis, senescence, and pro-inflammatory cytokines of NP and leads to the loss of extracellular matrix by mitochondrial dysfunction and the suppression of autophagy; on the other hand, the inhibition of Piezo1 can partly alleviate these effects.

Bioinspired MXene-Based User-Interactive Electronic Skin for Digital and Visual Dual-Channel Sensing.

User-interactive electronic skin (e-skin) that could convert mechanical stimuli into distinguishable outputs displays tremendous potential for wearable devices and health care applications. However, the existing devices have the disadvantages such as complex integration procedure and lack of the intuitive signal display function. Here, we present a bioinspired user-interactive e-skin, which is simple in structure and can synchronously achieve digital electrical response and optical visualization upon external mechanical stimulus. The e-skin comprises a conductive layer with a carbon nanotubes/cellulose nanofibers/MXene nanohybrid network featuring remarkable electromechanical behaviors, and a stretchable elastomer layer, which is composed of silicone rubber and thermochromic pigments. Furthermore, the conductive nanohybrid network with outstanding Joule heating performance can generate controllable thermal energy under voltage input and then achieve the dynamic coloration of silicone-based elastomer. Especially, such an innovative fusion strategy of digital data and visual images enables the e-skin to monitor human activities with evermore intuition and accuracy. The simple design philosophy and reliable operation of the demonstrated e-skin are expected to provide an ideal platform for next-generation flexible electronics.

Platelet-Activating Biominerals Enhanced Injectable Hydrogels With Superior Bioactivity for Bone Regeneration.

Refractory bone fracture, which is difficult to be treated, is a common clinical disease. Taking inspiration from the natural process of bone regeneration, we provide a biomimetic strategy to develop a new injectable biomaterial for repairing bone defects, which is mainly composed of platelets, fibrins, and biominerals. Biomineral nanoparticles (EACPNs) with an amorphous phase are prepared by an enzyme-catalyzed route and display a platelet-activating property. The composite hydrogel (EPH) of EACPNs, fibrins, and platelets is injectable, and has similar chemical properties to natural materials in bone regeneration. The dried EPH samples display a highly porous structure, which would be favorable for cell attachment and growth. The results from in vitro studies indicate that EPH has high biocompatibility and superior bioactivity in promoting the osteogenic differentiation of rat bone marrow stem cells (rBMSCs). Furthermore, the results from in vivo studies clearly indicate that EPH can induce the formation of new collagen and vessels in the defect area, thus leading to faster regeneration of bone defects at 2 weeks. Our study provides a strategy for designing new biomimetic materials, which may be favorable in the treatment of refractory bone fracture.

Research topics and hotspot trends of lumbar spondylolisthesis: A text-mining study with machine learning.

Objectives: The study aimed to conduct a bibliometric analysis of publications concerning lumbar spondylolisthesis, as well as summarize its research topics and hotspot trends with machine-learning based text mining. Methods: The data were extracted from the Web of Science Core Collection (WoSCC) database and then analyzed in Rstudio1.3.1 and CiteSpace5.8. Annual publication production and the top-20 productive authors over time were obtained. Additionally, top-20 productive journals and top-20 influential journals were compared by spine-subspecialty or not. Similarly, top-20 productive countries/regions and top-20 influential countries/regions were compared by they were developed countries/regions or not. The collaborative relationship among countries and institutions were presented. The main topics of lumbar spondylolisthesis were classified by Latent Dirichlet allocation (LDA) analysis, and the hotspot trends were indicated by keywords with strongest citation bursts. Results: Up to 2021, a total number of 4,245 articles concerning lumbar spondylolisthesis were finally included for bibliometric analysis. Spine-subspecialty journals were found to be dominant in the productivity and the impact of the field, and SPINE, EUROPEAN SPINE JOURNAL and JOURNAL OF NEUROSURGERY-SPINE were the top-3 productive and the top-3 influential journals in this field. USA, Japan and China have contributed to over half of the publication productivity, but European countries seemed to publish more influential articles. It seemed that developed countries/regions tended to produce more articles and more influential articles, and international collaborations mainly occurred among USA, Europe and eastern Asia. Publications concerning surgical management was the major topic, followed by radiographic assessment and epidemiology for this field. Surgical management especially minimally invasive technique for lumbar spondylolisthesis were the recent hotspots over the past 5 years. Conclusions: The study successfully summarized the productivity and impact of different entities, which should benefit the journal selection and pursuit of international collaboration for researcher who were interested in the field of lumbar spondylolisthesis. Additionally, the current study may encourage more researchers joining in the field and somewhat inform their research direction in the future.

Amorphous calcium magnesium phosphate nanocomposites with superior osteogenic activity for bone regeneration.

The seek of bioactive materials for promoting bone regeneration is a challenging and long-term task. Functionalization with inorganic metal ions or drug molecules is considered effective strategies to improve the bioactivity of various existing biomaterials. Herein, amorphous calcium magnesium phosphate (ACMP) nanoparticles and simvastatin (SIM)-loaded ACMP (ACMP/SIM) nanocomposites were developed via a simple co-precipitation strategy. The physiochemical property of ACMP/SIM was explored using transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and high-performance liquid chromatograph (HPLC), and the role of Mg2+ in the formation of ACMP/SIM was revealed using X-ray absorption near-edge structure (XANES). After that, the transformation process of ACMP/SIM in simulated body fluid (SBF) was also tracked to simulate and explore the in vivo mineralization performance of materials. We find that ACMP/SIM releases ions of Ca2+, Mg2+ and PO 4 3 - , when it is immersed in SBF at 37°C, and a phase transformation occurred during which the initially amorphous ACMP turns into self-assembled hydroxyapatite (HAP). Furthermore, ACMP/SIM displays high cytocompatibility and promotes the proliferation and osteogenic differentiation of MC3T3-E1 cells. For the in vivo studies, lamellar ACMP/SIM/Collagen scaffolds with aligned pore structures were prepared and used to repair a rat defect model in calvaria. ACMP/SIM/Collagen scaffolds show a positive effect in promoting the regeneration of calvaria defect after 12 weeks. The bioactive ACMP/SIM nanocomposites are promising as bone repair materials. Considering the facile preparation process and superior in vitro/vivo bioactivity, the as-prepared ACMP/SIM would be a potential candidate for bone related biomedical applications.

Bone-Targeting Polymer Vesicles for Effective Therapy of Osteoporosis.

With the aging of the population, postmenopausal osteoporosis becomes increasingly widespread and severe as fractures caused by osteoporosis may lead to permanent disabilities and even death. Inspired by extracellular vesicles that participate in bone remodeling, we present a biomimicking polymer vesicle for bone-targeted ß-estradiol (E2) delivery. This vesicle is self-assembled from a poly(ε-caprolactone)28-block-poly[(l-glutamic acid)7-stat-(l-glutamic acid-alendronic acid)4] (PCL28-b-P[Glu7-stat-(Glu-ADA)4]) diblock copolymer. The alendronic acid (ADA) on the coronas endows the polymer vesicles with a high bone affinity and acts synergistically with E2 to achieve an enhanced therapeutic effect. As confirmed with ovariectomized osteoporosis rat models, bone loss was significantly reversed as the recovery rates of total BMD (bone mineral density) and trabecular BMD were 70.4% and 99.3%, respectively. Overall, this work provides fresh insight into the treatment of osteoporosis.