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Bioabsorbable vs. titanium screws in first metatarsophalangeal joint arthrodesis: a pilot randomized controlled trial with 2-year follow-up.

INTRODUCTION: To assess the feasibility and preliminary clinical outcomes of bioabsorbable screw fixation in first metatarsophalangeal joint arthrodesis compared to conventional titanium screw fixation. METHODS: In this prospective pilot randomized controlled trial, 30 patients were allocated 1:1 to bioabsorbable or titanium cannulated lag screw fixation. Arthrodesis was performed using a cup-and-cone technique at two Finnish hospitals. Full weight-bearing in an orthopaedic shoe was allowed after six weeks. Outcomes included AOFAS and VA-FAS FA-VAS scores, union rates, and complications assessed at 3, 6, 12, and 24 months. RESULTS: Both groups showed significant functional improvement with no between-group differences. At 24 months, mean AOFAS scores were 89.1 (SD 2.7) in the titanium group and 90.0 (SD 0.0) in the bioabsorbable group (p = 0.23). Mean FA-VAS total scores (sum of pain, function, and complaints subscales) were 1948 (SE 59.4) in the titanium group and 1914 (SE 61.4) in the bioabsorbable group (p = 0.655). Union rate was 90% overall; nonunion occurred in one titanium and two bioabsorbable patients, all requiring revision. No implant-related complications or hardware removal surgeries were recorded. Degradation of bioabsorbable screws caused no adverse clinical or radiographic reactions. CONCLUSIONS: Bioabsorbable screws appear safe and feasible in first metatarsophalangeal joint arthrodesis, with preliminary outcomes comparable to titanium fixation. These findings support the conduct of a larger confirmatory trial. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03133039, registered 28 April 2017. https://clinicaltrials.gov/ct2/show/NCT03133039.

Humans

Cross-talk between NLRP3 and AIM2 inflammasomes in macrophage activation by LPS and titanium ions.

BACKGROUND: Periodontitis and peri-implantitis are chronic inflammatory diseases that contribute to tissue destruction and bone loss. Periodontitis is triggered by pathogenic bacteria, while peri-implantitis also involves metallic particles, which increase the inflammatory response. Both conditions are linked to the activation of inflammasomes, such as NLRP3 and AIM2, which facilitate the release of pro-inflammatory cytokines like IL-1β and IL-18 and induce pyroptosis. This study aims to investigate the activation of NLRP3 and AIM2 inflammasomes in macrophages exposed to bacterial and metallic components, as well as to explore the potential interplay between these two signaling pathways. METHODS: Human THP-1-derived macrophages were treated with bacterial lipopolysaccharide (LPS) and titanium ions to evaluate inflammasome activation. IL-1β secretion, ROS production, mitochondrial DNA release and pyroptosis were assessed. Additionally, macrophages deficient in NLRP3 and AIM2 were used to examine the roles of these inflammasomes in inflammatory responses. RESULTS: LPS and titanium ions synergistically activated NLRP3, resulting in increased IL-1β secretion, ROS production, and pyroptosis. Under these conditions, AIM2 was indirectly activated, as indicated by elevated mitochondrial DNA release. Notably, AIM2 expression was reduced in wild-type macrophages treated with LPS and titanium ions compared to LPS alone, however, in NLRP3-deficient cells, AIM2 expression was increased following LPS and titanium ions treatment. This upregulation of AIM2 in NLRP3-deficient cells was further reduced by ROS inhibition, which decreased mitochondrial DNA release. Additionally, NLRP3 knockout had a more pronounced effect on reducing IL-1β secretion and pyroptosis compared to AIM2 knockout, indicating a greater role of NLRP3 in these inflammatory responses. CONCLUSIONS: This study demonstrates that bacterial and metallic components drive the activation of both NLRP3 and AIM2 inflammasomes in macrophages, highlighting their roles in the inflammatory responses associated with periodontitis and peri-implantitis. The findings reveal a regulatory relationship between NLRP3 and AIM2, where the absence of one inflammasome can enhance the activity of the other. These results provide new insights into the mechanisms underlying inflammasome-mediated inflammation and suggest potential therapeutic targets for managing inflammatory diseases.

NLR Family, Pyrin Domain-Containing 3 Protein

Dietary Titanium Dioxide (E171) Alters the Colon Transcriptome-Evidence From a Human Dietary Intervention Study.

Food-grade titanium dioxide (E171) has been removed from the European food market due to concerns about its potential genotoxicity, yet human evidence remains limited. Given its continuous use outside the European Union, clarifying its potential hazard is essential for human risk assessment. In a randomized crossover study, 31 adults consumed 2&#xa0;mg/kg body weight/day of E171 for 2 weeks, with biospecimens collected after both control and exposure periods. Oral intake resulted in elevated titanium concentrations in feces (CTRL: 6.3&#xa0;mg/kg; E171: 377&#xa0;mg/kg). Particle characterization showed a median size of 228&#xa0;nm, with 9% <100&#xa0;nm. Systemic oxidative stress increased, evidenced by increased superoxide radical levels in whole blood (p = 0.057). Transcriptomic profiling of colon biopsies revealed activation of 73 pathways linked to oxidative stress, cellular metabolism, and colorectal cancer-associated processes. The observed transcriptional changes were consistent with findings of its proposed mode of action. This human intervention study characterizes the effects of dietary E171 following human gastrointestinal digestion and provides evidence that exposure to dietary E171 induces systemic oxidative stress and transcriptional changes in the colon. These findings strengthen regulatory concerns about E171 as a food additive and its potentially harmful effects on human gastrointestinal health.

Humans

Proteomic insights into the immunomodulatory effects of Ca/Sr co-doped sol-gel coatings for titanium implants.

Ionic functionalization of biomaterial coatings has emerged as a powerful strategy to regulate early host responses at the implant interface. However, how combined Ca/Sr incorporation governs the adsorbed proteome and downstream immune signaling remains poorly understood. This study analyses, employing in vitro tests and proteomics, the effect of adding Sr and Ca to Si-based coatings designed to bioactivate Ti implants. Hybrid Si-based coatings were synthesized by the sol-gel route with a fixed Ca content (0.5&#x202f;wt%) and increasing Sr contents (0.5, 1.0, 1.5&#x202f;wt%), and their physicochemical properties, ion release kinetics, and hydrolytic stability were characterized. The coatings remained highly crosslinked despite Ca/Sr incorporation, whereas the highest Sr content increased hydrolytic degradation to around 70% after 56 days. Proteomic analysis identified 183 adsorbed proteins, of which 56 were differentially adsorbed on Ca/Sr-coatings, mainly associated with immune and coagulation pathways. In vitro, RAW 264.7 showed increased gene expression of TNF-&#x3b1; and TGF-&#x3b2;; with an enhanced TNF-&#x3b1; secretion by the addition of Ca and Sr. In parallel, MC3T3-E1 indicated that Ca/Sr-coatings were not cytotoxic and did not impair cell proliferation. However, ALP activity was reduced in the co-doped groups, indicating that the immunomodulatory effects induced by Ca/Sr incorporation were not accompanied by enhanced early osteogenic differentiation. The Ca/Sr combination induced alterations in the adsorption of immune-related proteins, which correlated with the in vitro findings. The deeper insight into how Ca/Sr mixtures modulate protein adsorption on biomaterial surfaces may be key to understanding the immunomodulatory capacity of these bioactive cations.

Animals

Reversing the paradigm: Oxygen-dependent switch of nTiO&#x2082; from promoting to suppressing ARG conjugation.

The environmental spread of antibiotic resistance genes (ARGs) poses a significant public health threat. While nano-titanium dioxide (nTiO2) is known to promote ARG transfer, its role in prevalent anaerobic environments remains poorly understood. Therefore, we comprehensively evaluated the influence of nTiO2 exposure on the plasmid-mediated ARGs conjugation under aerobic/anaerobic conditions. Under aerobic conditions, nTiO2 significantly promoted the ARGs dissemination through both intra-genus (E. coli to E. coli) and inter-genus (E. coli to P. denitrificans) transfer. Reactive oxygen species (ROS) was determined as the decisive factor driving aerobic conjugation, which increased membrane permeability and downregulated conjugative pathways. Addition of ROS scavenger thiourea effectively abolished the stimulatory effect of nTiO&#x2082; on conjugative transfer. However, nTiO2 treatment significantly inhibited conjugative ARG transfer under anaerobic conditions. The dose-dependent inhibition was confirmed in anaerobic denitrification system. Exogenous H2O2 switched the inhibitory effect of nTiO&#x2082; on anaerobic conjugation. Physical barrier formed by nTiO&#x2082; adsorption might contribute to inhibited conjugative transfer of ARGs. Therefore, this study defines the distinct roles of the inhibitory physical effect caused by the adsorption barrier and promotive chemical effect induced by ROS in the nTiO&#x2082;-mediated ARG conjugation, which contributes to a deeper understanding of the environmental propagation mechanisms of ARGs under nanomaterial exposure.

Reactive Oxygen Species

Catalytic Enantioselective Addition of Aryl, Heteroaryl, and Alkenyl Halides to Aliphatic Aldehydes.

Cobalt complexes of chiral Josiphos catalyzed enantioselective addition of aryl, heteroaryl, and alkenyl halides to a wide range of linear and branched aliphatic aldehydes, without using directing groups. The new method was easily scalable with low loadings of cobalt catalysts, and its synthetic utility was demonstrated in concise synthesis of chiral carbinols that are key motifs of drugs or synthetic precursors. The cobalt catalyst also provided high diastereoselectivity in the addition of chiral amino aldehydes. Mechanistic studies suggest cationic complexes of aryl-cobalt(II) act as active species for asymmetric insertion. Lewis acidic titanium alkoxides assist ionization of aryl-cobalt halides to form cationic complexes. The lowest-energy transition states for insertion are stabilized by &#x3c0;-&#x3c0; stacking between the migrating aryl ring and P-phenyl ring of Josiphos.

aldehydes

RNA-seq Analysis of Peri-Implant Tissue Shows Differences in Immune, Notch, Wnt, and Angiogenesis Pathways in Aged Versus Young Mice.

The number of total joint replacements (TJRs) in the United States is increasing annually. Cementless implants are intended to improve upon traditional cemented implants by allowing bone growth directly on the surface to improve implant longevity. One major complication of TJR is implant loosening, which is related to deficient osseointegration in cementless TJRs. Although poor osseointegration in aged patients is typically attributed to decreased basal bone mass, little is known about the molecular pathways that compromise the growth of bone onto porous titanium implants. To identify the pathways important for osseointegration that are compromised by aging, we developed an approach for transcriptomic profiling of peri-implant tissue in young and aged mice using our murine model of osseointegration. Based on previous findings of changes of bone quality associated with aging, we hypothesized that aged mice have impaired activation of bone anabolic pathways at the bone-implant interface. We found that pathways most significantly downregulated in aged mice relative to young mice are related to angiogenic, Notch, and Wnt signaling. Downregulation of these pathways is associated with markedly increased expression of inflammatory and immune genes at the bone-implant interface in aged mice. These results identify osseointegration pathways affected by aging and suggest that an increased inflammatory response in aged mice may compromise peri-implant bone healing. Targeting the Notch and Wnt pathways, promoting angiogenesis, or modulating the immune response at the peri-implant site may enhance osseointegration and improve the outcome of joint replacement in older patients. &#xa9; 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

AGING

Bioaccumulation Patterns of Potentially Toxic Elements in Three Grouper Species from the Nizampatnam Coast, India: Multivariate Analysis and Risk Assessment.

The Indian Bay of Bengal coast represents an important marine fishing area and serves as a significant source of dietary protein for consumers. These highlights growing concerns regarding the bioaccumulation of potentially toxic elements (PTEs) in fish and the associated environmental and human health risks linked to their consumption. Thus, this study aims to assess the accumulation of PTEs (As (arsenic), Sr (strontium), Ti (titanium), Be (beryllium), Cd (cadmium), Sb (antimony), Pb (lead), Hg (mercury), and Li (lithium)) in the muscles of three groupers. The highest value (29.88&#x2009;&#xb1;&#x2009;0.17&#xa0;&#xb5;g/g dry wt.) was observed in Epinephelus areolatus for As, and the lowest in E. bleekeri for Be (0.59&#x2009;&#xb1;&#x2009;0.20&#xa0;&#xb5;g/kg dry wt.). Multivariate analyses (PCA and HCA) confirmed a very close relationship among the As, Cd, Sb, Ti, and Be, while Pb, Hg, Th, and Li had their own specific habitats of bioaccumulation, implying distinct inputs of PTE. Health risk evaluations reveal that As was the most hazardous PTE, with the incidence of toxic effects and cancer risk, especially for habitual consumers. However, Ti is the most hazardous PTE, posing the highest non-carcinogenic risk of the studied species. Metal-protein docking further showed the strong binding of Pb2+ and Sr2+ to Nrf2, p53, and DNMT1, indicating potential disruption of redox regulation, genomic stability, and epigenetic control. The findings indicate that the intake of the specified grouper species poses a significant arsenic-related health risk to people, underscoring the necessity for ongoing monitoring and management of PTE contaminants in fisheries.

Animals

Postoperative Curvature Loss in Three-Level Anterior Cervical Discectomy and Fusion With Zero-Profile Device.

PURPOSE: Cervical curvature loss is a frequent complication following 3-level anterior cervical discectomy and fusion (ACDF) using a Zero-Profile device. Consequently, the capacity of this device to maintain cervical sagittal alignment in 3-level ACDF remains highly controversial. This study aimed to identify potential predictors for postoperative curvature loss (PCL) and evaluate its impact on clinical outcomes. METHODS: A total of 113 patients who underwent ACDF for 3-level cervical degenerative disc disease (CDDD) between January 2021 and December 2023 were retrospectively reviewed. Demographic data, radiological parameters, and clinical outcomes were analyzed. Radiographic measures included cervical curvature, T1 slope, C2-7 sagittal vertical axis, and titanium plate and endplate (TPE) distance. Clinical outcomes were assessed using the Visual Analog Scale (VAS), Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores. Statistical analyses were performed using paired and independent t-tests, as well as Pearson correlation coefficients. RESULTS: The average curvature loss was 6.82&#xb0; from 1&#x2009;week postoperatively to the final follow-up (p&#x2009;<&#x2009;0.001). However, the final curvature (11.65&#xb0;) was maintained, representing a 4.33&#xb0; improvement compared to preoperative values. Significant correlations were observed between PCL and preoperative curvature (r&#x2009;=&#x2009;-0.368, p&#x2009;=&#x2009;0.013), preoperative T1 slope (r&#x2009;=&#x2009;-0.546, p&#x2009;<&#x2009;0.001), &#x2206;T1 slope (r&#x2009;=&#x2009;0.443, p&#x2009;=&#x2009;0.002), and &#x2206;TPE distance (r&#x2009;=&#x2009;0.417, p&#x2009;=&#x2009;0.004). PCL did not correlate with Japanese Orthopaedic Association (JOA) scores or arm VAS scores at the final follow-up. Nevertheless, patients with a PCL&#x2009;&#x2265;&#x2009;6&#xb0; exhibited significantly higher neck VAS (p&#x2009;=&#x2009;0.028) and NDI scores (p&#x2009;=&#x2009;0.041). CONCLUSION: Although contiguous 3-level ACDF with a Zero-Profile device may result in PCL, it preserves an improved cervical lordosis compared to the preoperative baseline. Low preoperative curvature and a low preoperative T1 slope are potentially predictive factors for PCL. Postoperative changes in TPE distance and T1 slope are significantly associated with PCL, suggesting a potential biomechanical link that requires direct validation. Furthermore, PCL may lead to higher neck VAS and NDI scores. Consequently, the Zero-Profile device may require careful consideration in 3-level CDDD patients presenting with low preoperative curvature and a low T1 slope. Importantly, the 6&#xb0; PCL threshold identified is preliminary and requires prospective validation before clinical application.

Humans

Aggregation-induced Electrochemiluminescence of AgNCs Enhanced with AuNPs@MXene Composites for Ultrasensitive Detection of microRNA.

MXene, a two-dimensional nanomaterial, has metal conductivity, high electronegativity, functionalized with surface groups, which make it widely applicable in catalysis and biosensing. However, studies on the principle of enhanced electrochemiluminescence (ECL) by MXene composites and the improvement of their performance in catalyzing the ECL reaction are still in their infancy. In this study, gold nanoparticles (AuNPs) are obtained by mild reductive reduction and loaded in&#x2005;situ on the Ti3C2Tx MXene surface to form the composites (AuNPs@MXene). In oxygenated PBS test buffer, AuNPs@MXene enhance the ECL emission of silver nanoclusters (AgNCs) with aggregation-induced electrochemiluminescence (AIECL) properties as luminophore. Approximately 7.5-fold enhancement of ECL signals is obtained by using two ECL enhancement strategies: an efficient AIECL emitter and a co-reaction accelerator. The special nucleic acid structure with "Three Way Junction (TWJ)" enables an ultra-sensitive detection of microRNA, providing an efficient and ultra-sensitive method for microRNA detection. The biosensor achieves a wide detection range of microRNA-21 from 100&#x2005;aM to 1&#x2005;nM, with a low detection limit of 31&#x2005;aM, and exhibits excellent stability, selectivity and high reproducibility in real samples.

MicroRNAs