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Acta Biomaterialia Apr 2024Cardiac pacing with temporary epicardial pacing wires (TEPW) is used to treat rhythm disturbances after cardiac surgery. Occasionally, TEPW cannot be mechanically...
Cardiac pacing with temporary epicardial pacing wires (TEPW) is used to treat rhythm disturbances after cardiac surgery. Occasionally, TEPW cannot be mechanically extracted and remain in the thorax, where they may rarely cause serious complications like migration and infection. We aim to develop bioresorbable TEPW that will dissolve over time even if postoperative removal is unsuccessful. In the present study, we demonstrate a completely bioresorbable design using molybdenum (Mo) as electric conductor and the resorbable polymers poly(D, L-lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) for electrically insulating double-coating. We compared the pacing properties of these Mo TEPW demonstrators to conventional steel TEPW in Langendorff-perfused rat hearts and observed similar functionality. In vitro, static immersion tests in simulated body fluid for up to 28 days elucidated the degradation behaviour of uncoated Mo strands and the influence of polymer coating thereon. Degradation was considerably reduced in double-coated Mo TEPW compared to the uncoated and the PLGA-coated condition. Furthermore, we confirmed good biocompatibility of Mo degradation products in the form of low cytotoxicity in cell cultures of human cardiomyocytes and cardiac fibroblasts. STATEMENT OF SIGNIFICANCE: Temporary pacing wires are routinely implanted on the heart surface to treat rhythm disturbances in the days following cardiac surgery. Subsequently, these wires are to be removed. When removal attempts are unsuccessful, wires are cut at skin level and the remainders are left inside the chest. Retained fragments may migrate within the body or become a centre of infection. These complications may be prevented using resorbable pacing wires. We manufactured completely resorbable temporary pacing wires using molybdenum as electrical conductor and assessed their function, degradation and biological compatibility. Our study represents an important step in the development of a safer approach to the treatment of rhythm disturbances after cardiac surgery.
Topics: Humans; Animals; Rats; Cardiac Pacing, Artificial; Pacemaker, Artificial; Molybdenum; Absorbable Implants; Pericardium
PubMed: 38432350
DOI: 10.1016/j.actbio.2024.02.039 -
Biosensors Nov 2023L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings....
L-tryptophan (L-TRP) is an essential amino acid responsible for the establishment and maintenance of a positive nitrogen equilibrium in the nutrition of human beings. Therefore, it is vital to quantify the amount of L-tryptophan in our body. Herein, we report the MoS/S@g-CN-modified glassy carbon electrode for the electrochemical detection of L-tryptophan (L-TRP). The MoS/S@g-CN composite was successfully synthesized using an efficient and cost-effective hydrothermal method. The physical and chemical properties of the synthesized composite were analyzed using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray analysis (EDX). The crystallite size of the composite was calculated as 39.4 nm, with porous balls of MoS decorated over the S@g-CN surface. The XPS spectrum confirmed the presence of Mo, S, O, C, and N elements in the sample. The synthesized nanocomposite was further used to modify the glassy carbon (GC) electrode (MoS/S@g-CN/GC). This MoS/S@g-CN/GC was used for the electrochemical detection of L-TRP using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. For the purpose of comparison, the effects of the scanning rate and the concentration of L-TRP on the current response for the bare GC, S@g-CN/GC, MoS/GC, and MoS/S@g-CN/GC were studied in detail. The MoS/S@g-CN-modified GC electrode exhibited a rational limit of detection (LoD) of 0.03 µM and a sensitivity of 1.74 µA/ µMcm, with excellent stability, efficient repeatability, and high selectivity for L-TRP detection.
Topics: Humans; Graphite; Tryptophan; Molybdenum; Carbon; Electrodes; Electrochemical Techniques
PubMed: 37998142
DOI: 10.3390/bios13110967 -
Molecules (Basel, Switzerland) Oct 2023Sulfite oxidase is one of five molybdenum-containing enzymes known in eukaryotes where it catalyzes the oxidation of sulfite to sulfate. This review covers the history... (Review)
Review
Sulfite oxidase is one of five molybdenum-containing enzymes known in eukaryotes where it catalyzes the oxidation of sulfite to sulfate. This review covers the history of sulfite oxidase research starting out with the early years of its discovery as a hepatic mitochondrial enzyme in vertebrates, leading to basic biochemical and structural properties that have inspired research for decades. A personal view on sulfite oxidase in plants, that sulfates are assimilated for their de novo synthesis of cysteine, is presented by Ralf Mendel with numerous unexpected findings and unique properties of this single-cofactor sulfite oxidase localized to peroxisomes. Guenter Schwarz connects his research to sulfite oxidase via its deficiency in humans, demonstrating its unique role amongst all molybdenum enzymes in humans. In essence, in both the plant and animal kingdoms, sulfite oxidase represents an important player in redox regulation, signaling and metabolism, thereby connecting sulfur and nitrogen metabolism in multiple ways.
Topics: Animals; Humans; Sulfite Oxidase; Molybdenum; Sulfites; Plants; Molybdenum Cofactors; Sulfates
PubMed: 37836841
DOI: 10.3390/molecules28196998 -
Molecules (Basel, Switzerland) Aug 2023Molybdenum-containing enzymes of the xanthine oxidase (XO) family are well known to catalyse oxygen atom transfer reactions, with the great majority of the characterised... (Review)
Review
Molybdenum-containing enzymes of the xanthine oxidase (XO) family are well known to catalyse oxygen atom transfer reactions, with the great majority of the characterised enzymes catalysing the insertion of an oxygen atom into the substrate. Although some family members are known to catalyse the "reverse" reaction, the capability to abstract an oxygen atom from the substrate molecule is not generally recognised for these enzymes. Hence, it was with surprise and scepticism that the "molybdenum community" noticed the reports on the mammalian XO capability to catalyse the oxygen atom abstraction of nitrite to form nitric oxide (NO). The lack of precedent for a molybdenum- (or tungsten) containing nitrite reductase on the nitrogen biogeochemical cycle contributed also to the scepticism. It took several kinetic, spectroscopic and mechanistic studies on enzymes of the XO family and also of sulfite oxidase and DMSO reductase families to finally have wide recognition of the molybdoenzymes' ability to form NO from nitrite. Herein, integrated in a collection of "personal views" edited by Professor Ralf Mendel, is an overview of my personal journey on the XO and aldehyde oxidase-catalysed nitrite reduction to NO. The main research findings and the path followed to establish XO and AO as competent nitrite reductases are reviewed. The evidence suggesting that these enzymes are probable players of the mammalian NO metabolism is also discussed.
Topics: Animals; Mammals; Molybdenum; Nitric Oxide; Nitrite Reductases; Nitrites; Oxidation-Reduction; Oxygen; Xanthine Oxidase
PubMed: 37570788
DOI: 10.3390/molecules28155819 -
Chemosphere Aug 2023Prenatal environmental factors may affect the development of the offspring and can bring long lasting consequences to the offspring's health. To date, only few studies...
BACKGROUND
Prenatal environmental factors may affect the development of the offspring and can bring long lasting consequences to the offspring's health. To date, only few studies have reported inconclusive association between prenatal single trace element exposure and visual acuity, and no studies have investigated the association between prenatal exposure to trace elements mixture and visual acuity in infants.
METHODS
In the prospective cohort study, grating acuity in infants (12 ± 1 months) was measured by Teller Acuity Cards II. Concentrations of 20 trace elements in maternal urine samples collected in early-trimester were measured by Inductively Coupled Plasma Mass Spectrometry. Elastic net regression (ENET) was applied to select important trace elements. Nonlinear associations of the trace elements levels with abnormal grating were explored using the restricted cubic spline (RCS) method. The associations between selected individual elements and abnormal grating acuity were further appraised using the logistic regression model. Then Bayesian Kernel Machine Regression (BKMR) was used to estimate the joint effects of mixture and interactions between trace elements combining with NLinteraction.
RESULTS
Of 932 mother-infant pairs, 70 infants had abnormal grating acuity. The ENET model produced 8 trace elements with non-zero coefficients, including cadmium, manganese, molybdenum, nickel, rubidium, antimony, tin and titanium. RCS analyses identified no nonlinear associations of the 8 elements with abnormal grating acuity. The single-exposure analyses using logistic regression revealed that prenatal molybdenum exposure possessed a significantly positive association with abnormal grating acuity (odds ratio [OR]: 1.44 per IQR increase, 95% confidence interval [CI]: 1.05, 1.96; P = 0.023), while prenatal nickel exposure presented with a significantly inverse association with abnormal grating acuity (OR: 0.64 per IQR increase, 95% CI: 0.45, 0.89; P = 0.009). Similar effects were also observed in BKMR models. Moreover, the BKMR models and NLinteraction method identified potential interaction between molybdenum and nickel.
CONCLUSIONS
We established that prenatal exposure to high concentration of molybdenum and low concentration of nickel was associated with the increased risk of abnormal visual acuity. Potential interaction may exist between molybdenum and nickel on abnormal visual acuity.
Topics: Pregnancy; Female; Humans; Infant; Trace Elements; Prospective Studies; Molybdenum; Nickel; Cohort Studies; Prenatal Exposure Delayed Effects; Bayes Theorem; Visual Acuity
PubMed: 37187369
DOI: 10.1016/j.chemosphere.2023.138905 -
Journal of Trace Elements in Medicine... Mar 2024Hair loss is a common dermatological condition including various types such as alopecia areata, androgenetic alopecia, etc. Minoxidil is a topical medication used for...
BACKGROUND
Hair loss is a common dermatological condition including various types such as alopecia areata, androgenetic alopecia, etc. Minoxidil is a topical medication used for treating hair loss, which is effective for various types of alopecia. However, minoxidil has limitations in treating hair loss, such as slow onset of action and low efficacy, and it cannot effectively inhibit one of the major pathogenic factors of hair loss - excessive oxidative stress.
METHODS
Transition metal elements with rapid electron transfer, such as molybdenum, have been extensively studied and applied for inhibiting oxidative stress. We established a mouse model for hair growth and intervened with nano-sized molybdenum, minoxidil, and a combination of both. The physicochemical properties of nano-sized molybdenum enabled it to mediate oxidative stress more quickly.
RESULTS
The results showed that nano-sized molybdenum can accelerate hair growth, increase the number of local hair follicles, and reduce the expression of oxidative stress-related molecules such as iNOS, COX2, and androgen receptors. The combination of nano-sized molybdenum and minoxidil showed an additive effect in promoting hair growth.
CONCLUSION
Our findings suggest that nano-sized molybdenum might be a potential topical medication for treating hair loss by inhibiting the oxidative stress pathway. Nano-sized molybdenum, alone or in combination with minoxidil, could be a promising therapeutic approach for patients with hair loss, particularly those who do not respond well to current treatments. Further clinical studies are warranted to confirm the efficacy and safety of this novel treatment.
Topics: Animals; Mice; Humans; Minoxidil; Antioxidants; Molybdenum; Double-Blind Method; Alopecia; Alopecia Areata; Treatment Outcome
PubMed: 38150949
DOI: 10.1016/j.jtemb.2023.127368 -
Nanomaterials (Basel, Switzerland) Aug 2023Molybdenum disulfide (MoS) is a layered transition metal-sulfur compound semiconductor that shows promising prospects for applications in optoelectronics and integrated...
Molybdenum disulfide (MoS) is a layered transition metal-sulfur compound semiconductor that shows promising prospects for applications in optoelectronics and integrated circuits because of its low preparation cost, good stability and excellent physicochemical, biological and mechanical properties. MoS with high quality, large size and outstanding performance can be prepared via chemical vapor deposition (CVD). However, its preparation process is complex, and the area of MoS obtained is difficult to control. Machine learning (ML), as a powerful tool, has been widely applied in materials science. Based on this, in this paper, a ML Gaussian regression model was constructed to explore the growth mechanism of MoS material prepared with the CVD method. The parameters of the regression model were evaluated by combining the four indicators of goodness of fit (r2), mean squared error (MSE), Pearson correlation coefficient (p) and -value (_val) of Pearson's correlation coefficient. After comprehensive comparison, it was found that the performance of the model was optimal when the number of iterations was 15. Additionally, feature importance analysis was conducted on the growth parameters using the established model. The results showed that the carrier gas flow rate (Fr), molybdenum sulfur ratio (R) and reaction temperature (T) had a crucial impact on the CVD growth of MoS materials. The optimal model was used to predict the size of molybdenum disulfide synthesis under 185,900 experimental conditions in the simulation dataset so as to select the optimal range for the synthesis of large-size molybdenum disulfide. Furthermore, the model prediction results were verified through literature and experimental results. It was found that the relative error between the prediction results and the literature and experimental results was small. These findings provide an effective solution to the preparation of MoS materials with a reduction in the time and cost of trial and error.
PubMed: 37630868
DOI: 10.3390/nano13162283 -
Advanced Science (Weinheim,... Aug 2023The fast conversion of hydrogen peroxide (H O ) into reactive oxygen species (ROS) at tumor sites is a promising anticancer strategy by manipulating nanomedicines with...
The fast conversion of hydrogen peroxide (H O ) into reactive oxygen species (ROS) at tumor sites is a promising anticancer strategy by manipulating nanomedicines with near-infrared light in the second region (NIR-II). However, this strategy is greatly compromised by the powerful antioxidant capacity of tumors and the limited ROS generation rate of nanomedicines. This dilemma mainly stems from the lack of an effective synthesis method to support high-density copper-based nanocatalysts on the surface of photothermal nanomaterials. Herein, a multifunctional nanoplatform (MCPQZ) with high-density cuprous (Cu O) supported molybdenum disulfide (MoS ) nanoflowers (MC NFs) is developed for the efficient killing of tumors via a potent ROS storm by an innovative method. Under NIR-II light irradiation, the ROS intensity and maximum reaction velocity (V ) produced by MC NFs are 21.6 and 33.8 times that of the non-irradiation group in vitro, which is much higher than most current nanomedicines. Moreover, the strong ROS storm in cancer cells is efficiently formed by MCPQZ (increased by 27.8 times compared to the control), thanks to the fact that MCPQZ effectively pre-weakens the multiple antioxidant systems of cancer cells. This work provides a novel insight to solve the bottleneck of ROS-based cancer therapy.
Topics: Reactive Oxygen Species; Copper; Molybdenum; Phototherapy; Antioxidants; Cell Line, Tumor
PubMed: 37340606
DOI: 10.1002/advs.202302208 -
The Science of the Total Environment Jan 2024In this study, 24 healthy male sheep were divided into four groups: the control group, Mo group (45 mg Mo·kg-1·BW), Cd group (1 mg Cd·kg-1·BW), and Mo + Cd...
In this study, 24 healthy male sheep were divided into four groups: the control group, Mo group (45 mg Mo·kg-1·BW), Cd group (1 mg Cd·kg-1·BW), and Mo + Cd group (45 mg Mo·kg-1·BW + 1 mg Cd·kg-1·BW). The experiment was last for 50 d. The results showed that Mo and Cd co-exposure induced histopathological changes and ultrastructural damage, decreased the mRNA and protein expression levels of BTB (blood-testis barrier)-related factors (CX-43, ZO-1, OCLN) (P < 0.05) and the T-SOD and CAT activity (P < 0.05), increased the MDA content (P < 0.05) and the proinflammatory factors levels (P < 0.05) in sheep testes. Moreover, the results showed that a sharp decline in BTB-related factors and antioxidase activity, and a significant increase in reactive oxygen species (ROS) levels (P < 0.05) and the expression levels of NLRP3 inflammasome-related factors (P < 0.05) in primary Sertoli cells (SCs) under Mo and Cd co-exposure. However, treatment with a ROS scavenger or NLRP3 inflammasome inhibitors could relieve BTB damage and oxidative injury, reduce the production of ROS (P < 0.05) and decrease the level of inflammatory factors (P < 0.05). Overall, these results indicated that Mo and Cd co-exposure reduced BTB-related protein levels and promoted ROS production and inflammatory reactions by activating the ROS/NLRP3 inflammasome pathway in sheep testes, which eventually induced reproductive toxicity.
Topics: Male; Animals; Sheep; Molybdenum; Cadmium; Reactive Oxygen Species; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Blood-Testis Barrier
PubMed: 37741404
DOI: 10.1016/j.scitotenv.2023.167267 -
Biosensors Aug 2023Cancer is a common illness with a high mortality. Compared with traditional technologies, biomarker detection, with its low cost and simple operation, has a higher... (Review)
Review
Cancer is a common illness with a high mortality. Compared with traditional technologies, biomarker detection, with its low cost and simple operation, has a higher sensitivity and faster speed in the early screening and prognosis of cancer. Therefore, extensive research has focused on the development of biosensors and the construction of sensing interfaces. Molybdenum disulfide (MoS) is a promising two-dimensional (2D) nanomaterial, whose unique adjustable bandgap shows excellent electronic and optical properties in the construction of biosensor interfaces. It not only has the advantages of a high catalytic activity and low manufacturing costs, but it can also further expand the application of hybrid structures through different functionalization, and it is widely used in various biosensors fields. Herein, we provide a detailed introduction to the structure and synthesis methods of MoS, and explore the unique properties and advantages/disadvantages exhibited by different structures. Specifically, we focus on the excellent properties and application performance of MoS and its composite structures, and discuss the widespread application of MoS in cancer biomarkers detection from both electrochemical and optical dimensions. Additionally, with the cross development of emerging technologies, we have also expanded the application of other emerging sensors based on MoS for early cancer diagnosis. Finally, we summarized the challenges and prospects of MoS in the synthesis, functionalization of composite groups, and applications, and provided some insights into the potential applications of these emerging nanomaterials in a wider range of fields.
Topics: Biomarkers, Tumor; Molybdenum; Catalysis; Electronics; Neoplasms
PubMed: 37754082
DOI: 10.3390/bios13090848