Coatless modification of 3D-printed Ti6Al4V implants through tailored Cu ion implantation combined with UV photofunctionalization to enhance cell attachment, osteogenesis and angiogenesis.

The three-dimensional-printed Ti6Al4V implant (3DTi) has been widely accepted for the reconstruction of massive bone defects in orthopedics owing to several advantages, such as its tailored shape design, avoiding bone graft and superior bone-implant interlock. However, the osteoinduction activity of 3DTi is inadequate when applied clinically even though it exhibits osteoconduction. This study developes a comprehensive coatless strategy for the surface improvement of 3DTi through copper (Cu) ion implantation and ultraviolet (UV) photofunctionalization to enhance osteoinductivity. The newly constructed functional 3DTi (UV/Ti-Cu) achieved stable and controllable Cu doping, sustained Cu2+ releasing, and increased surface hydrophilicity. By performing cellular experiments, we determined that the safe dose range of Cu ion implantation was less than 5×1016 ions/cm2. The implanted Cu2+ enhanced the ALP activity and the apatite formation ability of bone marrow stromal cells (BMSCs) while slightly decreasing proliferation ability. When combined with UV photofunctionalization, cell adhesion and proliferation were significantly promoted and bone mineralization was further increased. Meanwhile, UV/Ti-Cu was conducive to the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro, theoretically facilitating vascular coupling osteogenesis. In conclusion, UV/Ti-Cu is a novel attempt to apply two coatless techniques for the surface modification of 3DTi. In addition, it is considered a potential bone substrate for repairing bone defects.

Effects of exosomes derived from platelet-rich plasma on osteogenic differentiation of dental pulp stem cells.

Platelet-rich plasma (PRP) can cause osteogenic differentiation of dental pulp stem cells (DPSCs). However, the effect of exosomes derived from PRP (PRP-Exos) on osteogenic differentiation of DPSCs remains unclear. Herein, we evaluated the impact of PRP-Exos on osteogenic differentiation of DPSCs. PRP-Exos were isolated and identified by transmission electron microscopy (TEM) and western blotting (WB). Immunofluorescence staining was performed to evaluate endocytosis of PRP-Exos by DPSCs. Alkaline phosphatase staining, alizarin red staining, western blot and qRT-PCR were carried out to evaluate the DPSCs osteogenic differentiation. The sequencing microRNA (miRNA) was conducted to determine the microRNA profile of PRP-Exos treated and untreated DPSCs. The results showed that endocytosis of PRP-Exos stimulated DPSCs odontogenic differentiation by elevated expression of ALP, DMP-1, OCN, and RUNX2. ALP activity and calcified nodules formation of PRP-Exos treated DPSCs were considerably elevated relative to that of the control group. MicroRNA sequencing revealed that 112 microRNAs considerably varied in PRP-Exos treated DPSCs, of which 84 were elevated and 28 were reduced. Pathway analysis suggested that genes targeted by differentially expressed (DE) miRNAs were contributed to many signaling cascades, such as the Wnt cascade. 65 genes targeted by 30 DE miRNA were contributed to Wnt signaling. Thus, it can be infered that PRP-Exos could enhance osteogenic differentiation and alter the miRNA expression profile of DPSCs.

Complications and local recurrence of chondrosarcoma and chordoma treated by total tumor resection in thoracic and lumbar spine.

BACKGROUND: En bloc resection of spinal tumors is challenging and associated with a high incidence of complications; however, it offers the potential to reduce the risk of recurrence when a wide margin is achieved. This research aims to investigate the safety and efficacy of en bloc resection in treating thoracic and lumbar chondrosarcoma/chordoma. METHODS: Data from patients diagnosed with chondrosarcoma and chordoma in the thoracic or lumbar region, who underwent total en bloc or piecemeal resection at our institution over a 7-year period, were collected and regularly followed up. The study analyzed overall perioperative complications and compared differences in complications and local tumor recurrence between the two surgical methods. RESULTS: Seventeen patients were included, comprising 12 with chondrosarcoma and 5 with chordoma. Among them, 5 cases underwent intralesional piecemeal resection, while the remaining 12 underwent planned en bloc resection. The average surgical time was 684 min (sd = 287), and the mean estimated blood loss was 2300 ml (sd = 1599). Thirty-five complications were recorded, with an average of 2.06 perioperative complications per patient. 82% of patients (14/17) experienced at least one perioperative complication, and major complications occurred in 64.7% (11/17). Five patients had local recurrence during the follow-up, with a mean recurrence time of 16.2 months (sd = 7.2) and a median recurrence time of 20 months (IQR = 12.5). Hospital stays, operation time, blood loss, and complication rates did not significantly differ between the two surgical methods. The local recurrence rate after en bloc resection was lower than piecemeal resection, although not statistically significant (P = 0.067). CONCLUSIONS: The complication rates between the two surgical procedures were similar. Considering safety and local tumor control, en bloc resection is recommended as the primary choice for patients with chondrosarcoma/chordoma in the thoracic and lumbar regions who are eligible for this treatment.

A pig model of symptomatic spinal epidural hematoma.

PURPOSE: The purpose of this study was to establish an animal model capable of simulating the development and decompression process of symptomatic spinal epidural hematoma (SSEH). METHODS: A total of 16 male Bama miniature pigs were included in this study and randomly allocated into four groups: Group A (4 h 20 mmHg hematoma compression), Group B (4 h 24 mmHg hematoma compression), Group C (4 h 28 mmHg hematoma compression), and Group Sham (control). Real-time intra-wound hematoma compression values were obtained using the principle of connectors. Electrophysiological analyses, including the latency and amplitude of somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP), along with behavioral observations (Tarlov score), were performed to assess this model. RESULTS: ANOVA tests demonstrated significant differences in the latency and relative amplitude of SSEP and MEP between Groups C and Sham after 4 h of hematoma compression and one month after surgery (P < 0.01). Behavioral assessments 8 h after surgery indicated that animals subjected to 28 mmHg hematoma compression suffered the most severe spinal cord injury. Pearson correlation coefficient test suggested a negative correlation between the epidural pressure and Tarlov score (r = -0.700, p < 0.001). With the progression of compression and the escalation of epidural pressure, the latency of SSEP and MEP gradually increased, while the relative amplitude gradually decreased. CONCLUSIONS: When the epidural pressure reaches approximately 24 mmHg, the spinal cord function occurs progressive dysfunction. Monitoring epidural pressure would be an effective approach to assist to identify the occurrence of postoperative SSEH.

Distal Junctional Failures in Degenerative Thoracolumbar Hyperkyphosis.

OBJECTIVE: Degenerative thoracolumbar hyperkyphosis (DTH) is a disease that negatively affects individual health and requires surgical intervention, yet the ideal surgical approach and complications, especially distal junctional failures (DJF), remain poorly understood. This study aims to investigate DJF in DTH and to identify the risk factors for DJF so that we can improve surgical decision-making, and advance our knowledge in the field of spinal surgery to enhance patient outcomes. METHODS: This study retrospectively reviewed 78 cases (late osteoporotic vertebral compression fracture [OVCF], 51; Scheuermann's kyphosis [SK], 17; and degenerative disc diseases [DDD], 10) who underwent corrective surgery in our institute from 2008 to 2019. Clinical outcomes were assessed using health-related quality of life (HRQOL) measures, including the visual analogue scale (VAS) scores for back and leg pain, the Oswestry disability index (ODI), and the Japanese Orthopaedic Association (JOA) scoring system. Multiple radiographic parameters, such as global kyphosis (GK) and thoracolumbar kyphosis (TLK), were assessed to determine radiographic outcomes. Multivariate logistic regression analysis was employed to identify the risk factors associated with DJF. RESULTS: HRQOL improved, and GK, TLK decreased at the final follow-up, with a correction rate of 67.7% and 68.5%, respectively. DJF was found in 13 of 78 cases (16.7%), two cases had wedging in the disc (L3-4) below the instrumentation, one case had a fracture of the lowest instrumented vertebrae (LIV), one case had osteoporotic fracture below the fixation, nine cases had pull-out or loosening of the screws at the LIV and three cases (23.1%) required revision surgery. The DJF group had older age, lower computed tomography Hounsfield unit (CT HU), longer follow-up, more blood loss, greater preoperative sagittal vertical axis (SVA), and poorer postoperative JOA and VAS scores (back). The change in TLK level was larger in the non-DJF group. Post-sagittal stable vertebrae (SSV) moved cranially compared with pre-SSV. CONCLUSION: Age, CT HU, length of follow-up, estimated blood loss, and preoperative SVA were independent risk factors for DJF. We recommend fixation of the two vertebrae below the apex vertebrae for DTH to minimize surgical trauma.

Age-related bone diseases: Role of inflammaging.

Bone aging is characterized by an imbalance in the physiological and pathological processes of osteogenesis, osteoclastogenesis, adipogenesis, and chondrogenesis, resulting in exacerbated bone loss and the development of age-related bone diseases, including osteoporosis, osteoarthritis, rheumatoid arthritis, and periodontitis. Inflammaging, a novel concept in the field of aging research, pertains to the persistent and gradual escalation of pro-inflammatory reactions during the aging process. This phenomenon is distinguished by its low intensity, systemic nature, absence of symptoms, and potential for management. The mechanisms by which inflammaging contribute to age-related chronic diseases, particularly in the context of age-related bone diseases, remain unclear. The precise manner in which systemic inflammation induces bone aging and consequently contributes to the development of age-related bone diseases has yet to be fully elucidated. This article primarily examines the mechanisms underlying inflammaging and its association with age-related bone diseases, to elucidate the potential mechanisms of inflammaging in age-related bone diseases and offer insights for developing preventive and therapeutic strategies for such conditions.

[Clinical outcomes of 3D-printing stand-alone artificial vertebral body in anterior cervical surgeries].

OBJECTIVE: To explore the short-term outcomes of 3D-printing stand-alone artificial vertebral body (AVB) in the surgical procedure of anterior cervical corpectomy and fusion (ACCF). METHODS: Following the proposal of IDEAL (idea, development, exploration, assessment, and long-term follow-up) framework, we designed and conducted this single-armed, retrospective cohort study. The patients with cervical spondylotic myelopathy were recruited, and these patients exclusively received the surgical procedure of single-level ACCF in our single center. After the process of corpectomy, the size was tailored using different trials and the most suitable stand-alone AVB was then implanted. This AVB was manufactured by the fashion of 3D-printing. Two pairs of screws were inserted in an inclined way into the adjacent vertebral bodies, to stabilize the AVB. The participants were regularly followed-up after the operation. Their clinical data were thoroughly reviewed. We assessed the neurological status according to Japanese Orthopedic Association (JOA) scale. We determined the fusion based on imaging examination six months after the operation. The recorded clinical data were analyzed using specific software and they presented in suitable styles. Paired t test was employed in comparison analysis. RESULTS: In total, there were eleven patients being recruited eventually. The patients were all followed up over six months after the operation. The mean age of the cohort was (57.2±10.2) years. The mean operation time was (76.1±23.1) min and the median bleeding volume was 150 (100, 200) mL. The postoperative course was uneventful for all the cases. Dysphagia, emergent hematoma, and deterioration of neurological function did not occur. Mean JOA scores were 13.2±2.2 before the operation and 16.3±0.8 at the final follow-up, which were significantly different (P < 0.001). The mean recovery rate of neurological function was 85.9%. By comparing the imaging examinations postoperatively and six months after the operation, we found that the average subsidence length was (1.2±1.1) mm, and that there was only one cases (9.1%) of the severe subsidence (>3 mm). We observed significant improvement of cervical lordosis after the operation (P=0.013). All the cases obtained solid fusion. CONCLUSION: 3D-printing stand-alone AVB presented favorable short-term outcome in one-level ACCF in this study. The fusion rate of this zero-profile prosthesis was satisfactory and the complication rate was relatively low.

Comparison of En Bloc Resection and Intralesional Excision for Re-resection of Giant Cell Tumors of the Spine.

OBJECTIVE: Re-resection of spinal giant cell tumors is an exceedingly difficult procedure. Moreover, the prognosis of patients with en bloc resection or intralesional excision for re-resection has rarely been reported. This study aimed to compare the prognostic value of en bloc resection with that of intralesional excision in patients undergoing re-resection for giant cell tumors of the spine. METHODS: This retrospective analysis evaluated patients who underwent revision surgeries for relapse of giant cell tumors of the spine at our center between January 2005 and January 2021. Local progression-free survival represents the duration between en bloc resection or intralesional excision and tumor recurrence. Neurological recovery, survival rates, local control, and complications were evaluated. The Kaplan-Meier estimator was used for survival analysis. RESULTS: A total of 22 patients (nine men and 13 women) with a mean age of 34.1 (range 19-63) years were included. Significant statistical differences were found in the local tumor recurrence rate between patients treated with en bloc resection and those treated with intralesional excision (p < 0.05). The 5- and 10-year local progression-free survival rates were both 90% in the en bloc resection group, while in the intralesional excision group, the 5-year local progression-free survival rate was 80% with a 10-year rate of 45.7%. The en bloc resection group had a lower local tumor recurrence rate than that of the intralesional excision group (p < 0.05), but the former had a higher rate of complications (p = 0.015). CONCLUSIONS: This study revealed a low local recurrence rate in patients who underwent en bloc resection for giant cell tumors, while the perioperative complication rate was high.

The influence and therapeutic effect of microbiota in systemic lupus erythematosus.

Systemic erythematosus lupus (SLE) is an autoimmune disease involving multiple organs that poses a serious risk to the health and life of patients. A growing number of studies have shown that commensals from different parts of the body and exogenous pathogens are involved in SLE progression, causing barrier disruption and immune dysregulation through multiple mechanisms. However, they sometimes alleviate the symptoms of SLE. Many factors, such as genetic susceptibility, metabolism, impaired barriers, food, and sex hormones, are involved in SLE, and the microbiota drives the development of SLE either by depending on or interacting with these factors. Among these, the crosstalk between genetic susceptibility, metabolism, and microbiota is a hot topic of research and is expected to lay the groundwork for the amelioration of the mechanism, diagnosis, and treatment of SLE. Furthermore, the microbiota has great potential for the treatment of SLE. Ideally, personalised therapeutic approaches should be developed in combination with more specific diagnostic methods. Herein, we provide a comprehensive overview of the role and mechanism of microbiota in lupus of the intestine, oral cavity, skin, and kidney, as well as the therapeutic potential of the microbiota.

Proteomics Analysis of Knee Subchondral Bone Identifies Differentially Expressed Proteins Associated with Osteoarthritis.

Osteoarthritis (OA) is a prevalent debilitating whole-joint disorder. Currently, a growing number of proteomic studies have been performed to evaluate molecular biomarkers in several tissues from OA patients; however, little is known about the protein profiles in subchondral bone of OA. In this study, proteomic analysis was performed on subchondral bone from patients with OA to identify differentially expressed proteins (DEPs). Bioinformatics tools were used to further investigate these DEPs. Thereafter, DEPs were validated in the samples from patients with OA, as well as in bilateral ovariectomy-induced OA (OVX-OA) rats using immunohistochemistry. A comprehensive subchondral bone proteome profile of patients with OA was constructed. Additionally, biological information analysis showed that a majority of DEPs participated in the dysregulation of the complement and coagulation cascades. The validation experiments suggested that SerpinA5, the protein involved in the complement and coagulation cascades, was significantly increased in severely damaged subchondral bone of patients with OA compared to the control group. Furthermore, the increase of SerpinA5 in OVX-OA rats compared to control rats was also confirmed. Our results indicated that the dysregulation of coagulation and complement pathways plays a role in the progression of OA, and it provides a promising therapeutic target of OA.

Erratum: Simvastatin/hydrogel-loaded 3D-printed titanium alloy scaffolds suppress osteosarcoma via TF/NOX2-associated ferroptosis while repairing bone defects.

[This corrects the article DOI: 10.1016/j.bioactmat.2023.11.001.].

Border fences reduce potential for transboundary migration of Marco Polo Sheep (Ovis ammon polii) in the Pamir Plateau.

Border fences have severely impeded the transboundary migration of a number of large mammals worldwide, with central Asia being one of the most impacted. The Marco Polo sheep (Ovis ammon polii), an iconic species of Pamir, is threatened in its transboundary movement by increasing border fencing among their five distributed countries, including Tajikistan, Kyrgyzstan, China, Afghanistan, and Pakistan. In this study, by building ensemble species distribution models, we found that eastern Tajikistan had the largest suitable Macro Polo sheep habitat (about 42 % of the total suitable habitat), followed by China (about 32 %). We used least-cost paths to identify 51 ecological corridors including 5 transboundary ecological corridors, which may be important to maintain connectivity in both domestic and transboundary regions. To assess the potential barrier effect of border fences, we assessed four scenarios (30, 40, 50 and 60°) corresponding to the upper limit of the slope for the construction of fences. In areas too steep for fencing, these could be used by wild sheep to cross barriers or borders and may represent migration or movement routes, defined as natural passages. In the most pessimistic Scenario 60, only 25 migratory passages along the border fences were identified, compared to 997 in the most optimistic scenario (Scenario 30), indicating a strong negative effect of intensive border fencing on the transboundary movement of Marco Polo sheep. The establishment of transnational conservation parks, and ensuring permeability is maintained in key areas, could have a positive impact on the connectivity and persistence of Marco Polo sheep populations, and provide important lessons for other large migratory mammals in transboundary regions.

Simvastatin/hydrogel-loaded 3D-printed titanium alloy scaffolds suppress osteosarcoma via TF/NOX2-associated ferroptosis while repairing bone defects.

Postoperative anatomical reconstruction and prevention of local recurrence after tumor resection are two vital clinical challenges in osteosarcoma treatment. A three-dimensional (3D)-printed porous Ti6Al4V scaffold (3DTi) is an ideal material for reconstructing critical bone defects with numerous advantages over traditional implants, including a lower elasticity modulus, stronger bone-implant interlock, and larger drug-loading space. Simvastatin is a multitarget drug with anti-tumor and osteogenic potential; however, its efficiency is unsatisfactory when delivered systematically. Here, simvastatin was loaded into a 3DTi using a thermosensitive poly (lactic-co-glycolic) acid (PLGA)-polyethylene glycol (PEG)-PLGA hydrogel as a carrier to exert anti-osteosarcoma and osteogenic effects. Newly constructed simvastatin/hydrogel-loaded 3DTi (Sim-3DTi) was comprehensively appraised, and its newfound anti-osteosarcoma mechanism was explained. Specifically, in a bone defect model of rabbit condyles, Sim-3DTi exhibited enhanced osteogenesis, bone in-growth, and osseointegration compared with 3DTi alone, with greater bone morphogenetic protein 2 expression. In our nude mice model, simvastatin loading reduced tumor volume by 59%-77 % without organic damage, implying good anti-osteosarcoma activity and biosafety. Furthermore, Sim-3DTi induced ferroptosis by upregulating transferrin and nicotinamide adenine dinucleotide phosphate oxidase 2 levels in osteosarcoma both in vivo and in vitro. Sim-3DTi is a promising osteogenic bone substitute for osteosarcoma-related bone defects, with a ferroptosis-mediated anti-osteosarcoma effect.

Factors that impact the patellofemoral contact stress in the TKA: a review.

Abnormal retro patellar stress is believed to contribute to patellofemoral complications after total knee arthroplasty (TKA), but the causal link between TKA and patellofemoral contact stress remains unclear. By reviewing the relevant studies, we found that both TKA implantation and additional patellar resurfacing increase retro patellar pressure. The rotation and size of the femoral component, thickness and position of the patellar component, installation of the tibial component, prosthesis design and soft tissue balance further influence patellofemoral stress. Specific measures can be applied to reduce stress, including the installation of the femoral prosthesis with an appropriate external rotation angle, placing the tibial component at a more posterior position and the patellar button at a more medial position, avoiding over-sized femoral and patellar components, selecting posterior-stabilized design rather than cruciate-retaining design, using gender-specific prosthesis or mobile-bearing TKA system, and releasing the lateral retinaculum or performing partial lateral facetectomy. Despite these measures, the principle of individualization should be followed to optimize the patellofemoral biomechanics.

Fabrication of a composite 3D-printed titanium alloy combined with controlled in situ drug release to prevent osteosarcoma recurrence.

Osteosarcoma is a malignant bone tumor occurring in adolescents. Surgery combined with adjuvant or neoadjuvant chemotherapy is the standard treatment. However, systemic chemotherapy is associated with serious side effects and a high risk of postoperative tumor recurrence, leading to a high amputation rate and mortality in cancer patients. Implant materials that can simultaneously repair large bone defects and prevent osteosarcoma recurrence are in urgent need. Herein, an intelligent system comprising 3D-printed titanium scaffold (TS) and pH-responsive PEGylated paclitaxel prodrugs was fabricated for bone defect reconstruction and recurrence prevention following osteosarcoma surgery. The drug-loaded implants exhibited excellent stability and biocompatibility for supporting the activity of bone stem cells under normal body fluid conditions and the rapid release of drugs in response to faintly acidic environments. An in vitro study demonstrated that five human osteosarcoma cell lines could be efficiently eradicated by paclitaxel released in an acidic microenvironment. Using mice models, we demonstrated that the drug-loaded TS can enable a pH-responsive treatment of postoperative tumors and effectively prevent osteosarcoma recurrence. Therefore, local implantation of this composite scaffold may be a promising topical therapeutic method to prevent osteosarcoma recurrence.

Surgery for metastatic spinal differentiated thyroid cancer: feasibility, outcome, and prognostic factors.

Study design: A retrospective cohort study. Objectives: This study aims to report the surgical outcome of metastatic spinal differentiated thyroid cancer (MSDTC) and analyze the factors affecting the prognosis. Methods: Thirty-five patients were recruited in our single institution who underwent spinal surgery and adjuvant therapies from 2009 to 2019. Two surgical procedures, total en-bloc spondylectomy and debulking surgery, were undertaken. Their clinical data, postoperative events, and survival data were collected and analyzed. Survival time and associated factors were further analyzed. Results: The cohort had a median survival time of 60 months. The mean visual analog scale scores and the Karnofsky performance score improved postoperatively (p < 0.05). The patients' Frankel grade was elevated for cases with preoperative neurological deficits (p < 0.05). In 31 patients who underwent debulking surgery, 41.9% (n = 13) had local recurrences, and radiotherapy reduced the risk of local relapse (p < 0.05). Preoperative and postoperative Frankel grades and radioactive iodine (RAI) therapy were associated with the patients' survival in the univariate analysis (p < 0.05). Furthermore, a multivariate regression analysis showed the postoperative Frankel grade as an independent prognostic factor. Conclusion: Pain, quality of life, and neurological status of patients can be effectively improved after surgery. Radiotherapy can reduce the risk of local recurrences, whereas RAI therapy has a limited effect on local and extraspinal tumor control. Neurological status was independently associated with the patients' survival.

Predicting post-laminoplasty kyphosis in cervical spondylotic myelopathy patients without preoperative kyphosis: a retrospective study.

BACKGROUND: This study aimed to determine potential risk factors for post-laminoplasty kyphosis and the effect of postoperative kyphosis on neurologic function recovery. METHODS: A total of 266 patients with cervical spondylotic myelopathy (CSM) underwent traditional cervical laminoplasty with a minimum of a 12-month follow-up period. The patients were divided into non-kyphosis (NK group) and kyphosis (K group) groups based on the postoperative C2-7 Cobb angle. Clinical and radiological measurements were collected preoperatively and at the final follow-up. RESULTS: Of the 266 patients, 26 (9.77%) developed postoperative kyphosis at the final follow-up. The postoperative Japanese Orthopedic Association score did not differ significantly between the NK and K groups (P > 0.05). The postoperative numeric rating scale (NRS) also showed no significant difference between the NK and K groups; however, postoperative NRS improved better than the preoperative values in the NK group (P < 0.001). Multivariate analysis revealed that the preoperative C2-7 extension Cobb angle and C2-7 Cobb angle were independent predictors of post-laminoplasty kyphosis. Cut-off values for predicting postoperative kyphosis were a C2-7 extension Cobb angle of 18.00° and a C2-7 Cobb angle of 9.30°. CONCLUSIONS: Low preoperative C2-7 extension Cobb angle and C2-7 Cobb angle may be associated with post-laminoplasty kyphosis in CSM patients without preoperative kyphosis. The cut-off value of the C2-7 extension Cobb angle and C2-7 Cobb angle were 18.00° and 9.30°, respectively.

Misdiagnosis of primary dumbbell chordoma of the cervical spine.

AIM: This study aimed to analyze the clinical characteristics and outcomes of patients with primary dumbbell chordoma of the cervical spine and to summarize the causes of misdiagnosis. METHODS: The clinical data of patients were retrospectively collected. The diagnostic process, surgical procedures, and outcomes were analyzed, then the difference was compared between dumbbell and non-dumbbell chordomas of the cervical spine. RESULTS: This study included six patients with primary dumbbell chordoma (one male and five females) with a mean age of 32.2 ± 24.5 years (range: 5-61 years). Five cases with no computed tomography (CT) examination before the first operation were misdiagnosed, and on magnetic resonance imaging (MRI), primary dumbbell chordoma showed the following specific features: extensive invasion of the surrounding soft tissues with an obscure boundary (≥5 cm), intervertebral disc sparing, and hemorrhagic necrosis, furthermore, the CT features included atypical destructive vertebral lesions, minimal intralesional calcification, and neural foraminal enlargement. After comparison with non-dumbbell chordomas, it show statistical difference (p < 0.05) in terms of calcification, foramen enlargement, FNA, misdiagnosis rate but with different recurrent rate. CONCLUSION: Primary dumbbell chordomas of the cervical spine can easily be misdiagnosed as neurogenic tumors. Preoperative CT-guided fine-needle aspiration puncture biopsy helps make an accurate diagnosis. Gross total excision with postoperative radiotherapy has been proven effective in reducing the recurrence rate.

Immunotoxicity of metal and metal oxide nanoparticles: from toxic mechanisms to metabolism and outcomes.

The influence of metal and metal oxide nanomaterials on various fields since their discovery has been remarkable. They have unique properties, and therefore, have been employed in specific applications, including biomedicine. However, their potential health risks cannot be ignored. Several studies have shown that exposure to metal and metal oxide nanoparticles can lead to immunotoxicity. Different types of metals and metal oxide nanoparticles may have a negative impact on the immune system through various mechanisms, such as inflammation, oxidative stress, autophagy, and apoptosis. As an essential factor in determining the function and fate of immune cells, immunometabolism may also be an essential target for these nanoparticles to exert immunotoxic effects in vivo. In addition, the biodegradation and metabolic outcomes of metal and metal oxide nanoparticles are also important considerations in assessing their immunotoxic effects. Herein, we focus on the cellular mechanism of the immunotoxic effects and toxic effects of different types of metal and metal oxide nanoparticles, as well as the metabolism and outcomes of these nanoparticles in vivo. Also, we discuss the relationship between the possible regulatory effect of nanoparticles on immunometabolism and their immunotoxic effects. Finally, we present perspectives on the future research and development direction of metal and metal oxide nanomaterials to promote scientific research on the health risks of nanomaterials and reduce their adverse effects on human health.