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Journal of Orthopaedic Surgery and... Nov 2023Titanium (Ti) dental implants face risks of early failure due to bacterial adhesion and biofilm formation. It is thus necessary to endow the implant surface with...
Titanium (Ti) dental implants face risks of early failure due to bacterial adhesion and biofilm formation. It is thus necessary to endow the implant surface with antibacterial ability. In this study, magnesium oxide (MgO) coatings were prepared on Ti by combining micro-arc oxidation (MAO) and electrophoretic deposition (EPD). The MgO nanoparticles homogeneously deposited on the microporous surface of MAO-treated Ti, yielding increasing coverage with the EPD time increased to 15 to 60 s. After co-culture with Porphyromonas gingivalis (P. gingivalis) for 24 h, 48 h, and 72 h, the coatings produced antibacterial rates of 4-53 %, 27-71 %, and 39-79 %, respectively, in a dose-dependent manner. Overall, EPD for 45 s offered satisfactory comprehensive performance, with an antibacterial rate 79 % at 72 h and a relative cell viability 85 % at 5 d. Electron and fluorescence microscopies revealed that, both the density of adherent bacterial adhesion on the surface and the proportion of viable bacteria decreased with the EPD time. The morphology of cells on the surface of each group was intact and there was no significant difference among the groups. These results show that, the MgO coating deposited on MAO-treated Ti by EPD had reasonably good in vitro antibacterial properties and cytocompatibility.
Topics: Magnesium Oxide; Titanium; Coated Materials, Biocompatible; Anti-Bacterial Agents; Prostheses and Implants; Surface Properties
PubMed: 38012792
DOI: 10.1186/s13018-023-04390-4 -
Journal of Dairy Science Feb 2023The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)] and its interaction...
Production, physiological response, and calcium and magnesium balance of lactating Holstein cows fed different sources of supplemental magnesium with or without ruminal buffer.
The objective of this study was to evaluate the effects of dietary replacement of magnesium oxide (MgO) with calcium-magnesium hydroxide [CaMg(OH)] and its interaction with ruminal buffer (sodium sesquicarbonate) supplementation on production, Ca and Mg balance, and overall physiological response of mid-lactation Holstein dairy cows. Sixty cows averaging 40.5 ± 7.0 kg of milk/d were used. Treatments were assigned following a 2 × 2 factorial arrangement: (1) MgO, (2) MgO + buffer, (3) CaMg(OH), or (4) CaMg(OH) + buffer. Diets were formulated to have 16.5% of crude protein, 1.82 Mcal/kg of net energy for lactation, 0.67% Ca, 0.39% P, and 0.25% Mg, all on a dry matter (DM) basis. Treatments were individually top dressed. Milk production, composition, and DM intake were evaluated. A subsample of 20 cows were randomly selected for the evaluation of Ca and Mg balance, blood gases, and electrolytes. Ruminal fluid was also collected for evaluation of pH and Ca and Mg solubility. Effects of Mg source, buffer, and the interaction Mg source × buffer were analyzed through orthogonal contrasts. An interaction of Mg source × buffer was found for DM intake and feed efficiency, in which cows fed CaMg(OH) had a similar feed efficiency regardless of ruminal buffer inclusion; however, when cows were fed MgO, the inclusion of buffer reduced feed efficiency. No effects on body weight and milk yield were observed. Buffer addition tended to increase the concentrations of fat, protein, and solids-not-fat, without affecting the yields of these milk components. Magnesium source and buffer did not affect ruminal fluid, blood, urine, or fecal pH; however, buffer supplementation increased urinary pH. Treatment with CaMg(OH) increased blood concentration of HCO, total CO, and base excess compared with cows fed MgO. No differences were observed in the ruminal solubility of Ca and Mg or on milk or urinary Ca and Mg excretion. Greater plasma Mg concentration was observed for animals fed MgO compared with cows fed CaMg(OH); however, both sources were above the threshold recommended in the literature for dairy cows. Also, a reduction in fecal Mg excretion was observed in animals fed CaMg(OH). In summary, we provide evidence that CaMg(OH) could replace MgO without affecting performance, overall physiological response, or Ca and Mg balance of mid-lactating dairy Holstein cows.
Topics: Female; Cattle; Animals; Lactation; Magnesium; Calcium; Magnesium Oxide; Milk; Diet; Calcium, Dietary; Rumen; Animal Feed; Digestion
PubMed: 36526456
DOI: 10.3168/jds.2022-22583 -
Renewable & Sustainable Energy Reviews Jan 2021Solar photovoltaic/thermal technology has been widely utilized in building service area as it generates thermal and electrical energy simultaneously. In order to improve... (Review)
Review
Solar photovoltaic/thermal technology has been widely utilized in building service area as it generates thermal and electrical energy simultaneously. In order to improve the photovoltaic/thermal system performance, nanofluids are employed as the thermal fluid owing to its high thermal conductivity. This paper summarizes the state-of-the-art of the photovoltaic/thermal systems with different loop-pipe configurations (including heat pipe, vacuum tube, roll-bond, heat exchanger, micro-channel, U-tube, triangular tube and heat mat) and nanoparticles (including Copper-oxide, Aluminium-oxide, Silicon carbide, Tribute, Magnesium-oxide, Cerium-oxide, Tungsten-oxide, Titanium-oxide, Zirconia-oxide, Graphene and Carbon). The influences of the critical parameters like nanoparticle optical and thermal properties, volume fraction, mass flux and mass flow rates, on the photovoltaic/thermal system performance are for the optimum energy efficiency. Furthermore, the structure and manufacturing of solar cells, micro-thermometry analysis of solar cells and recycling process of photovoltaic panels are explored. At the end, the standpoints, recommendations and potential future development on the solar photovoltaic/thermal system with various configurations and nanofluids are deliberated to overcome the barriers and challenges for the practical application. This study demonstrates that the advanced photovoltaic/thermal configuration could improve the system energy efficiency approximately 15%-30% in comparison with the conventional type whereas the nanofluid is able to boost the efficiency around 10%-20% compared to that with traditional working fluid.
PubMed: 34234621
DOI: 10.1016/j.rser.2020.110254 -
Frontiers in Chemistry 2021Nanotechnology has become a very advanced and popular form of technology with huge potentials. Nanotechnology has been very well explored in the fields of electronics,... (Review)
Review
Nanotechnology has become a very advanced and popular form of technology with huge potentials. Nanotechnology has been very well explored in the fields of electronics, automobiles, construction, medicine, and cosmetics, but the exploration of nanotecnology's use in agriculture is still limited. Due to climate change, each year around 40% of crops face abiotic and biotic stress; with the global demand for food increasing, nanotechnology is seen as the best method to mitigate challenges in disease management in crops by reducing the use of chemical inputs such as herbicides, pesticides, and fungicides. The use of these toxic chemicals is potentially harmful to humans and the environment. Therefore, using NPs as fungicides/ bactericides or as nanofertilizers, due to their small size and high surface area with high reactivity, reduces the problems in plant disease management. There are several methods that have been used to synthesize NPs, such as physical and chemical methods. Specially, we need ecofriendly and nontoxic methods for the synthesis of NPs. Some biological organisms like plants, algae, yeast, bacteria, actinomycetes, and fungi have emerged as superlative candidates for the biological synthesis of NPs (also considered as green synthesis). Among these biological methods, endophytic microorganisms have been widely used to synthesize NPs with low metallic ions, which opens a new possibility on the edge of biological nanotechnology. In this review, we will have discussed the different methods of synthesis of NPs, such as top-down, bottom-up, and green synthesis (specially including endophytic microorganisms) methods, their mechanisms, different forms of NPs, such as magnesium oxide nanoparticles (MgO-NPs), copper nanoparticles (Cu-NPs), chitosan nanoparticles (CS-NPs), β-d-glucan nanoparticles (GNPs), and engineered nanoparticles (quantum dots, metalloids, nonmetals, carbon nanomaterials, dendrimers, and liposomes), and their molecular approaches in various aspects. At the molecular level, nanoparticles, such as mesoporous silica nanoparticles (MSN) and RNA-interference molecules, can also be used as molecular tools to carry genetic material during genetic engineering of plants. In plant disease management, NPs can be used as biosensors to diagnose the disease.
PubMed: 34113600
DOI: 10.3389/fchem.2021.613343 -
Drug Delivery and Translational Research Sep 2023Diabetic wounds are a serious complication of diabetes mellitus (DM) that can lead to persistent infection, amputation, and even death. Prolonged oxidative stress has...
Diabetic wounds are a serious complication of diabetes mellitus (DM) that can lead to persistent infection, amputation, and even death. Prolonged oxidative stress has been widely recognized as a major instigator in the development of diabetic wounds; therefore, oxidative stress is considered a promising therapeutic target. In the present study, Keap1/Nrf2 signaling was confirmed to be activated in streptozotocin (STZ)-induced diabetic mice and methylglyoxal (MGO)-treated human umbilical vein endothelial cells (HUVECs). Knockdown of Keap1 by siRNA reversed the increase in Keap1 levels, promoted the nuclear translocation of Nrf2, and increased the expression of HO-1, an antioxidant protein. To explore therapeutic delivery strategies, milk-derived exosomes (mEXOs) were developed as a novel, efficient, and non-toxic siRNA carrier. SiRNA-Keap1 (siKeap1) was loaded into mEXOs by sonication, and the obtained mEXOs-siKeap1 were found to promote HUVEC proliferation and migration while relieving oxidative stress in MGO-treated HUVECs. Meanwhile, in a mouse model of diabetic wounds, injection of mEXOs-siKeap1 significantly accelerated diabetic wound healing with enhanced collagen formation and neovascularization. Taken together, these data support the development of Keap1 knockdown as a potential therapeutic strategy for diabetic wounds and demonstrated the feasibility of mEXOs as a scalable, biocompatible, and cost-effective siRNA delivery system. The therapeutic effect of siKeap1-loaded mEXOs on diabetic wound healing was assessed. First, we found that the expression of Keap1 was upregulated in the wounds of diabetic mice and in human umbilical vein endothelial cells (HUVECs) pretreated with methylglyoxal (MGO). Next, we extracted exosomes from raw milk by differential centrifugation and loaded siKeap1 into milk-derived exosomes by sonication. The in vitro application of the synthetic complex (mEXOs-siKeap1) was found to increase the nuclear localization of Nrf2 and the expression of the antioxidant protein HO-1, thus reversing oxidative stress. Furthermore, in vivo mEXOs-siKeap1 administration significantly accelerated the healing rate of diabetic wounds (Scheme 1). Scheme 1 Schematic diagram. A Synthesis of mEXOs-siKeap1 complex. B Mechanism of mEXOs-siKeap1 in vitro. C The treatment effect of mEXOs-siKeap1 on an in vivo mouse model of diabetic wounds.
Topics: Mice; Humans; Animals; Antioxidants; Kelch-Like ECH-Associated Protein 1; Diabetes Mellitus, Experimental; RNA, Small Interfering; Milk; Exosomes; NF-E2-Related Factor 2; Magnesium Oxide; Pyruvaldehyde; Wound Healing; Oxidative Stress; Human Umbilical Vein Endothelial Cells
PubMed: 36749479
DOI: 10.1007/s13346-023-01306-x -
Scientific Reports Jan 2022The silver, magnesium oxide and gyrotactic microorganism-based hybrid nanofluid flow inside the conical space between disc and cone is addressed in the perspective...
The silver, magnesium oxide and gyrotactic microorganism-based hybrid nanofluid flow inside the conical space between disc and cone is addressed in the perspective of thermal energy stabilization. Different cases have been discussed between the spinning of cone and disc in the same or counter wise directions. The hybrid nanofluid has been synthesized in the presence of silver Ag and magnesium oxide MgO nanoparticulate. The viscous dissipation and the magnetic field factors are introduced to the modeled equations. The parametric continuation method (PCM) is utilized to numerically handle the modeled problem. Magnesium oxide is chemically made up of Mg and O ions that are bound by a strong ionic connection and can be made by pyrolyzing Mg(OH) (magnesium hydroxide) and MgCO (magnesium carbonate) at high temperature (700-1500 °C). For metallurgical, biomedical and electrical implementations, it is more efficient. Similarly, silver nanoparticle's antibacterial properties could be employed to control bacterial growth. It has been observed that a circulating disc with a stationary cone can achieve the optimum cooling of the cone-disk apparatus while the outer edge temperature remains fixed. The thermal energy profile remarkably upgraded with the magnetic effect, the addition of nanoparticulate in base fluid and Eckert number.
Topics: Anti-Bacterial Agents; Bacteria; Magnesium; Magnesium Hydroxide; Magnesium Oxide; Magnetic Fields; Metal Nanoparticles; Models, Theoretical; Motion; Nanocomposites; Nanotechnology; Numerical Analysis, Computer-Assisted; Silver Compounds; Temperature; Time Factors; Viscosity
PubMed: 34996921
DOI: 10.1038/s41598-021-03077-2 -
Biomaterials Advances Mar 2022One of the most common magnesium (Mg) applications in the biomedical field is in cardiovascular stents. Although Mg is an essential element for homeostasis, Mg is highly...
One of the most common magnesium (Mg) applications in the biomedical field is in cardiovascular stents. Although Mg is an essential element for homeostasis, Mg is highly reactive, and locally high Mg concentrations can have toxic effects on the surrounding tissue. One strategy to circumvent the Mg toxicity is using coatings or surface modifications that prevent the leaching of excessive Mg ions. In the current study, commercially pure magnesium (c.p Mg) was modified through plasma electrolytic oxidation (PEO) to produce a protective coating primarily composed of Mg oxide (MgO) and Mg hydroxide (Mg(OH)), which limits leaching of free Mg ions from the base material. As we intend to use this material to produce vascular stents, a biological evaluation of its performance is warranted. Primary human umbilical vein endothelial cells (HUVECs) and smooth muscle cells (SMCs) were the study object. The leaching of free Mg ions from the oxidized materials was investigated, as was its effect on local pH changes. We also investigated the influence of corrosion products, the effects of elevated free Mg concentrations and pH on the cellular behavior on the integrity of monolayers of HUVECs was studied in a static and dynamic model. Results showed that the harmful effect of Mg on cells due to changes in pH and a high concentration of Mg ions could decrease with the influence of flow diffusing corrosion products such as MgO, Mg(OH), and H among the system. Independently, Mg concentration and pH affected the cell activity of SMCs and HUVECs. Finally, to investigate the influence of leachables on vasomotor function, we exposed porcine aortic rings to PEO-modified Mg stents and assessed endothelial-dependent relaxation. Pure Mg reduced vasorelaxation from 100% in control samples to 30%. Oppositely, PEO-modified Mg did not affect the vasomotor function. Overall, we conclude from this study that the use of PEO coatings reduces the degradation rate of the material reducing the Mg release resulting in better cell viability and vessel function compared to the bare material.
Topics: Alloys; Animals; Coated Materials, Biocompatible; Human Umbilical Vein Endothelial Cells; Humans; Magnesium; Magnesium Hydroxide; Magnesium Oxide; Swine
PubMed: 35581088
DOI: 10.1016/j.msec.2022.112693 -
Biochimica Et Biophysica Acta.... Aug 2022The immune system plays an essential role in protecting the body against pathogens. Immune cells are activated during infections, resulting in a metabolic shift from... (Review)
Review
The immune system plays an essential role in protecting the body against pathogens. Immune cells are activated during infections, resulting in a metabolic shift from oxidative phosphorylation to glycolysis. During glycolysis, methylglyoxal (MGO) can be formed as a by-product. As a highly reactive dicarbonyl compound, MGO can rapidly react with proteins to form advanced glycation end products (AGEs). MGO and MGO-derived AGEs have been implicated in the development of insulin resistance, type 2 diabetes and its complications and several other age-related inflammatory diseases. MGO has been found in adipose tissue, atherosclerosis plaques and inflamed livers. Aside from the potential harmful role of MGO, there are studies showing beneficial effects of MGO as a defense mechanism during infections and diseases. In this review, we summarize anti-microbial effects of MGO and the link between MGO and immune cell activation, as potential mediator during host defense.
Topics: Diabetes Mellitus, Type 2; Humans; Immunity; Insulin Resistance; Magnesium Oxide; Pyruvaldehyde
PubMed: 35500827
DOI: 10.1016/j.bbadis.2022.166425 -
Cancer Treatment Reviews Apr 2024Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Cancer-related pain often requires opioid treatment with opioid-induced constipation (OIC) as its most frequent gastrointestinal side-effect. Both for prevention and treatment of OIC osmotic (e.g. polyethylene glycol) and stimulant (e.g. bisacodyl) laxatives are widely used. Newer drugs such as the peripherally acting µ-opioid receptor antagonists (PAMORAs) and naloxone in a fixed combination with oxycodone have become available for the management of OIC. This systematic review and meta-analysis aims to give an overview of the scientific evidence on pharmacological strategies for the prevention and treatment of OIC in cancer patients.
METHODS
A systematic search in PubMed, Embase, Web of Science and the Cochrane Library was completed from inception up to 22 October 2022. Randomized and non-randomized studies were systematically selected. Bowel function and adverse drug events were assessed.
RESULTS
Twenty trials (prevention: five RCTs and three cohort studies; treatment: ten RCTs and two comparative cohort studies) were included in the review. Regarding the prevention of OIC, three RCTs compared laxatives with other laxatives, finding no clear differences in effectivity of the laxatives used. One cohort study showed a significant benefit of magnesium oxide compared with no laxative. One RCT found a significant benefit for the PAMORA naldemedine compared with magnesium oxide. Preventive use of oxycodone/naloxone did not show a significant difference in two out of three other studies compared to oxycodone or fentanyl. A meta-analysis was not possible. Regarding the treatment of OIC, two RCTs compared laxatives, of which one RCT found that polyethylene glycol was significantly more effective than sennosides. Seven studies compared an opioid antagonist (naloxone, methylnaltrexone or naldemedine) with placebo and three studies compared different dosages of opioid antagonists. These studies with opioid antagonists were used for the meta-analysis. Oxycodone/naloxone showed a significant improvement in Bowel Function Index compared to oxycodone with laxatives (MD -13.68; 95 % CI -18.38 to -8.98; I = 58 %). Adverse drug event rates were similar amongst both groups, except for nausea in favour of oxycodone/naloxone (RR 0.51; 95 % CI 0.31-0.83; I = 0 %). Naldemedine (NAL) and methylnaltrexone (MNTX) demonstrated significantly higher response rates compared to placebo (NAL: RR 2.07, 95 % CI 1.64-2.61, I = 0 %; MNTX: RR 3.83, 95 % CI 2.81-5.22, I = 0 %). With regard to adverse events, abdominal pain was more present in treatment with methylnaltrexone and diarrhea was significantly more present in treatment with naldemedine. Different dosages of methylnaltrexone were not significantly different with regard to both efficacy and adverse drug event rates.
CONCLUSIONS
Magnesium oxide and naldemedine are most likely effective for prevention of OIC in cancer patients. Naloxone in a fixed combination with oxycodone, naldemedine and methylnaltrexone effectively treat OIC in cancer patients with acceptable adverse events. However, their effect has not been compared to standard (osmotic and stimulant) laxatives. More studies comparing standard laxatives with each other and with opioid antagonists are necessary before recommendations for clinical practice can be made.
Topics: Humans; Laxatives; Analgesics, Opioid; Narcotic Antagonists; Constipation; Oxycodone; Opioid-Induced Constipation; Magnesium Oxide; Cohort Studies; Naloxone; Polyethylene Glycols; Neoplasms; Drug-Related Side Effects and Adverse Reactions; Quaternary Ammonium Compounds; Naltrexone
PubMed: 38452708
DOI: 10.1016/j.ctrv.2024.102704 -
Heliyon Sep 2023In recent years, dental resin materials have become increasingly popular for cavity filling. However, these materials can shrink during polymerization, leading to... (Review)
Review
In recent years, dental resin materials have become increasingly popular for cavity filling. However, these materials can shrink during polymerization, leading to microleakages that enable bacteria to erode tooth tissue and cause secondary caries. As a result, there is great clinical demand for the development of antibacterial resins. The principle of antibacterial resin includes contact killing and filler-release killing of bacteria. For contact killing, quaternary ammonium salts (QACs) and antibacterial peptides (AMPs) can be added. For filler-release killing, chlorhexidine (CHX) and nanoparticles are used. These antibacterial agents are effective against gram-positive bacteria, gram-negative bacteria, fungi, and more. Among them, QACs has a lasting antibacterial effect, and silver nanoparticles even have a certain ability to kill viruses. Biocompatibility-wise, QACs, AMPs, and CHX have low cytotoxicity to cells when added into the resin. However, nanoparticles with smaller particle sizes have higher cytotoxicity. In terms of mechanical properties, QACs, AMPs, and CHX do not negatively affect the resin. However, the addition of magnesium oxide can have a negative impact. This paper reviews the types and antibacterial principles of commonly used antibacterial resins in recent years, evaluates their antibacterial effect, biological safety, and mechanical properties, and provides references for selecting clinical filling materials.
PubMed: 37662807
DOI: 10.1016/j.heliyon.2023.e19078