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ACS Nano Jul 2018Biodegradable polymers have been extensively used in biomedical applications, ranging from regenerative medicine to medical devices. However, the acidic byproducts...
Biodegradable polymers have been extensively used in biomedical applications, ranging from regenerative medicine to medical devices. However, the acidic byproducts resulting from degradation can generate vigorous inflammatory reactions, often leading to clinical failure. We present an approach to prevent acid-induced inflammatory responses associated with biodegradable polymers, here poly(lactide- co-glycolide), by using oligo(lactide)-grafted magnesium hydroxide (Mg(OH)) nanoparticles, which neutralize the acidic environment. In particular, we demonstrated that incorporating the modified Mg(OH) nanoparticles within degradable coatings on drug-eluting arterial stents efficiently attenuates the inflammatory response and in-stent intimal thickening by more than 97 and 60%, respectively, in the porcine coronary artery, compared with that of drug-eluting stent control. We also observed that decreased inflammation allows better reconstruction of mouse renal glomeruli in a kidney tissue regeneration model. Such modified Mg(OH) nanoparticles may be useful to extend the applicability and improve clinical success of biodegradable devices used in various biomedical fields.
Topics: Animals; Cell Survival; Cells, Cultured; Drug-Eluting Stents; Humans; Inflammation; Magnesium Hydroxide; Mice; Nanoparticles; Polylactic Acid-Polyglycolic Acid Copolymer; U937 Cells
PubMed: 29812907
DOI: 10.1021/acsnano.8b02365 -
Acta Biomaterialia Jun 2018Artificial scaffolds made up of various synthetic biodegradable polymers have been reported to have many advantages including cheap manufacturing, easy scale up, high...
UNLABELLED
Artificial scaffolds made up of various synthetic biodegradable polymers have been reported to have many advantages including cheap manufacturing, easy scale up, high mechanical strength, convenient manipulation, and molding into an unlimited variety of shapes. However, the synthetic biodegradable polymers still have the insufficiency for cartilage regeneration owing to their acidic degradation products. To reduce acidification by degradation of synthetic polymers, we incorporated magnesium hydroxide (MH) nanoparticles into porous polymer scaffold not only to effectively neutralize the acidic hydrolysate but also to minimize the structural disturbance of scaffolds. The neutralization effect of poly(D,L-lactic-co-glycolic acid; PLGA)/MH scaffold was confirmed with the maintenance of neutral pH, contrary to a PLGA scaffold with low pH. Further, the scaffolds were applied to evaluate the chondrogenic differentiation of the human bone marrow mesenchymal stem cells. In in vitro study, the PLGA/MH scaffold enhanced the chondrogenesis markers and reduced the calcification, compared to the PLGA scaffold. Additionally, the PLGA/MH scaffold reduced the release of inflammatory cytokines, compared to the PLGA scaffold, as the cell death decreased. Moreover, the addition of MH reduced necrotic cell death at the early stage of chondrogenic differentiation. Further, the necrotic cell death by the PLGA scaffold was mediated by cleavage of caspase-1, the so-called interleukin 1-converting enzyme, and MH alleviated it as well as nuclear factor kappa B expression. Furthermore, the PLGA/MH scaffold highly supported chondrogenic healing of rat osteochondral defect sites in in vivo study. Therefore, it was suggested that a synthetic polymer scaffold containing MH could be a novel healing tool to support cartilage regeneration and further treatment of orthopedic patients.
STATEMENT OF SIGNIFICANCE
Synthetic polymer scaffolds have been widely utilized for tissue regeneration. However, they have a disadvantage of releasing acidic products through degradation. This paper demonstrated a novel type of synthetic polymer scaffold with pH-neutralizing ceramic nanoparticles composed of magnesium hydroxide for cartilage regeneration. This polymer showed pH-neutralization property during polymer degradation and significant enhancement of chondrogenic differentiation of mesenchymal stem cells. It reduced not only chondrogenic calcification but also release of proinflammatory cytokines. Moreover, it has an inhibitory effect on necrotic cell death, particularly caspase-1-mediated necrotic cell death (pyroptosis). In in vivo study, it showed higher healing rate of the damaged cartilage in a rat osteochondral defect model. We expected that this novel type of scaffold can be effectively applied to support cartilage regeneration and further treatment of orthopedic patients.
Topics: Chondrogenesis; Humans; Magnesium Hydroxide; Mesenchymal Stem Cells; Nanoparticles; Polylactic Acid-Polyglycolic Acid Copolymer; Tissue Scaffolds
PubMed: 29673840
DOI: 10.1016/j.actbio.2018.04.022 -
ACS Applied Materials & Interfaces Jul 2021Based on the promising biomedical developments in wound healing strategies, herein, a new nanobiocomposite scaffold was designed and presented by incorporation of...
Hybrid Bionanocomposite Containing Magnesium Hydroxide Nanoparticles Embedded in a Carboxymethyl Cellulose Hydrogel Plus Silk Fibroin as a Scaffold for Wound Dressing Applications.
Based on the promising biomedical developments in wound healing strategies, herein, a new nanobiocomposite scaffold was designed and presented by incorporation of carboxymethyl cellulose hydrogels prepared using epichlorohydrin as a cross-linking agent (CMC hydrogel), a natural silk fibroin (SF) protein, and magnesium hydroxide nanoparticles (Mg(OH) NPs). Biological evaluation of the CMC hydrogel/SF/Mg(OH) nanobiocomposite scaffold was conducted via in vitro cell viability assays and in vivo assays, red blood cell hemolysis, and antibiofilm assays. Considering the cell viability percentage of Hu02 cells (84.5%) in the presence of the prepared nanobiocomposite after 7 days, it was indicated that this new nanoscaffold was biocompatible. The signs of excellent hemocompatibility and the high antibacterial activity were observed due to the low-point hemolytic effect (8.3%) and high-level potential in constraining the biofilm formation with a low OD value (0.13). Moreover, in vivo wound healing assay results indicated that the wound healing method was faster in mice treated with the prepared nanobiocomposite scaffold (82.29%) than the control group (75.63%) in 12 days. Apart from the structural characterization of the CMC hydrogel/SF/Mg(OH) nanobiocomposite through FTIR, EDX, FESEM, and TG analyses, compressive mechanical tests, contact angle, porosity, and swelling ratio studies indicated that the combination of the CMC hydrogel structure with SF protein and Mg(OH) NPs could significantly impact Young's modulus (from 11.34 to 10.14 MPa), tensile strength (from 299.35 to 250.78 MPa), elongation at break (12.52 to 12.84%), hydrophilicity, and water uptake capacity (92.5%).
Topics: Animals; Anti-Bacterial Agents; Bandages; Biofilms; Carboxymethylcellulose Sodium; Cell Line; Elastic Modulus; Fibroins; Hemolysis; Humans; Hydrogels; Magnesium Hydroxide; Male; Mice, Inbred BALB C; Nanocomposites; Nanoparticles; Pseudomonas aeruginosa; Tensile Strength; Wound Healing; Mice
PubMed: 34278788
DOI: 10.1021/acsami.1c07285 -
Water Science and Technology : a... 2015Application of magnesium hydroxide as a coagulant for treating high pH reactive orange wastewater was studied. The coagulation performance and magnesium...
Application of magnesium hydroxide as a coagulant for treating high pH reactive orange wastewater was studied. The coagulation performance and magnesium hydroxide-reactive orange floc properties were investigated under different dosages, feeding modes and pH values. Flocculation index (FI) was then discussed with controlled experiments using an intelligent particle dispersion analyzer and optimum coagulant dose of 150 mg/L (magnesium ion) was obtained for pH value 12. The results showed that the optimum magnesium ion dose tended to decrease with the increase of initial pH value. One time addition feeding mode led to relatively large FI value and higher removal efficiency compared with other addition modes. All of the flocs under investigation showed a limited capacity for re-growth when they had been previously broken. Based on the changes of zeta potential and floc properties, charge neutralization and precipitate enmeshment were proposed to be the main coagulation mechanisms.
Topics: Azo Compounds; Flocculation; Hydrogen-Ion Concentration; Magnesium Hydroxide; Sulfuric Acid Esters; Waste Disposal, Fluid; Wastewater
PubMed: 25945846
DOI: 10.2166/wst.2015.083 -
Journal of Chemical Neuroanatomy Nov 2023Alzheimer's disease (AD) is a neurodegenerative disease marked by mitochondrial dysfunction, amyloid-β (Aβ) aggregation, and neuronal cell loss. G-protein-coupled...
Gelatin/polyethylene glycol-loaded magnesium hydroxide nanocomposite to attenuate acetylcholinesterase, neurotoxicity, and activation of GPR55 protein in rat models of Alzheimer's disease.
Alzheimer's disease (AD) is a neurodegenerative disease marked by mitochondrial dysfunction, amyloid-β (Aβ) aggregation, and neuronal cell loss. G-protein-coupled receptor 55 (GPR55) has been used as a promising target for insulin receptors in diabetes therapy, but GPR55's role in AD is still unidentified. Gelatin (GE) and polyethylene glycol (PEG) polymeric hydrogels are commonly used in the drug delivery system. Therefore, the aim of the present study was the preparation of magnesium hydroxide nanocomposite using Clitoria ternatea (CT) flower extract, GE, and PEG (GE/PEG/Mg(OH)NCs) by the green precipitation method. The synthesized GE/PEG/Mg(OH)NCs were used to determine the effect of GPR55 activation of intracerebroventricular administration on streptozotocin (ICV-STC)-induced cholinergic dysfunction, oxidative stress, neuroinflammation, and cognitive deficits. The GE/PEG/Mg(OH)NCs were administered following bilateral ICV-STC administration (3 mg/kg) in experimental rats. Neurobehavioral assessments were performed using a Morris water maze (MWM) and a passive avoidance test (PA). Cholinergic and antioxidant activity, oxidative stress, and mitochondrial complex activity were estimated in the cortex and hippocampus through biochemical analysis. Inflammatory markers (TNF-α, IL-6, and IL-1β) were determined using the ELISA method. Our study results demonstrated that the GE/PEG/Mg(OH)NCs treatment significantly improved spatial and non-spatial memory functions in behavioral studies. Moreover, the treatment with GE/PEG/Mg(OH)NCs group significantly attenuated cholinergic dysfunction, oxidative stress, and inflammatory markers, and also highly improved anti-oxidant activity (GSH, SOD, CAT, and GPx) in the cortex and hippocampus regions. The western blot results suggest the activation of the GPR55 protein expression through GE/PEG/Mg(OH)NCs. The histopathological studies showed clear cytoplasm and healthy neurons, effectively promoting neuronal activity. Furthermore, the molecular docking results demonstrated the binding affinity and potential interactions of the compounds with the AChE enzyme. In conclusion, the GE/PEG/Mg(OH)NCs treated groups showed reduced neurotoxicity and have the potential as a therapeutic agent to effectively target AD.
Topics: Animals; Rats; Acetylcholinesterase; Alzheimer Disease; Antioxidants; Cholinergic Agents; Disease Models, Animal; Gelatin; Hippocampus; Magnesium Hydroxide; Molecular Docking Simulation; Neurodegenerative Diseases; Oxidative Stress; Polyethylene Glycols; Receptors, Cannabinoid; Receptors, G-Protein-Coupled; Cholinesterase Inhibitors; Nanoparticles
PubMed: 37708946
DOI: 10.1016/j.jchemneu.2023.102337 -
Environmental Technology Jan 2022Magnesium hydroxide is commonly used as a coagulant for treating reactive dyes wastewater. However, the flocs are relatively small and coagulation process needs longer...
Magnesium hydroxide is commonly used as a coagulant for treating reactive dyes wastewater. However, the flocs are relatively small and coagulation process needs longer sedimentation time. Large flocs and short operation time are important for good coagulation performance. Coagulation floc formation and growth processes using magnesium hydroxide and polyacrylamide (PAM) dual-coagulant were investigated with controlled experiments through flocculation index (FI), floc size distribution, zeta potential, scanning electron microscopy and Fourier transform infrared spectroscopy. The final average floc size reached 58.5 and 4.96 μm with and absence of PAM addition during slow mixing periods. PAM feeding time and magnesium hydroxide formation time can affect the floc formation and growth processes. The results showed that floc formed rapidly during magnesium hydroxide generation within 90 s and flocs aggregated together by PAM bridging function. Reactive orange removal efficiency reached 99.3% with rapid mixing 250 rpm at 90 s during 100 mg/L magnesium ion addition, then adding 6 mg/L PAM at the beginning of slow mixing period in dual-coagulant system.
Topics: Acrylic Resins; Aluminum Hydroxide; Azo Compounds; Flocculation; Magnesium Hydroxide; Sulfuric Acid Esters; Water Purification
PubMed: 32633211
DOI: 10.1080/09593330.2020.1791970 -
Biomaterials Science Feb 2021Although drug-eluting stents (DESs) are mainly coated with biodegradable polymers such as PLGA and PLLA, their acidic degradation products can alter the local...
Although drug-eluting stents (DESs) are mainly coated with biodegradable polymers such as PLGA and PLLA, their acidic degradation products can alter the local microenvironment and affect the homeostasis of adjacent tissue. Previously, we developed anti-inflammatory PLGA-based materials including magnesium hydroxide (MH) to relieve the side effects caused by PLGA degradation. However, the underlying molecular mechanism of its protective effects has not yet been clarified. Here, we demonstrated the pathological mechanism of vascular endothelial activation caused by PLGA by-products. The PLGA by-products accumulated in HCAECs through MCT1, followed by oxidative stress and the activation of the MAPK/NF-κB signaling pathway. Finally, the PLGA by-products increased the expression of VCAM-1 as well as the secretion of proinflammatory cytokines. However, the addition of MH particles significantly diminished the activation of this molecular pathway and the expression of inflammation-related factors induced by acidic PLGA degradation products. Furthermore, Mg2+ released from MH particles restored endothelial function in both intracellular and extracellular spaces. Taken together, MH particles prevent the accumulation of PLGA degradation products in HCAECs, thereby repressing the associated vascular endothelial activation. These findings on the biochemical mechanisms are expected to provide important clues for addressing the safety issues in nearly all biodegradable polymer-based implants.
Topics: Absorbable Implants; Drug-Eluting Stents; Endothelium, Vascular; Magnesium Hydroxide; Polymers
PubMed: 33245077
DOI: 10.1039/d0bm01656j -
Journal of Pharmaceutical Sciences May 1981The electrophoretic mobility of magnesium hydroxide was studied as a function of the concentration of its potential-determining ions, namely, of the magnesium ions, and...
The electrophoretic mobility of magnesium hydroxide was studied as a function of the concentration of its potential-determining ions, namely, of the magnesium ions, and of the hydroxide ions or pH. The zero point of charge was located at approximately 10.8. The zeta-potential of magnesium hydroxide below this pH was positive. The addition of magnesium nitrate to magnesium hydroxide suspensions increased the positive zeta-potential and lowered the pH. The low solubility of magnesium hydroxide in water prevented the attainment of substantial concentrations of magnesium ions in solution. Increasing the hydroxide-ion concentration or the pH produced charge inversion. The largest negative zeta-potential was attained at pH 11.5. Further increases in pH produced no significant increase in the negative value of the zeta-potential.
Topics: Chemical Phenomena; Chemistry; Electrophoresis; Hydrogen-Ion Concentration; Kinetics; Magnesium; Magnesium Hydroxide
PubMed: 7241347
DOI: 10.1002/jps.2600700505 -
Journal of the American Veterinary... May 1996To assess the effect of aluminum hydroxide/magnesium hydroxide antacid and bismuth subsalicylate on gastric pH in clinically normal horses and to develop guidelines on... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
OBJECTIVE
To assess the effect of aluminum hydroxide/magnesium hydroxide antacid and bismuth subsalicylate on gastric pH in clinically normal horses and to develop guidelines on the use of these agents for treatment of peptic ulcer disease in horses.
DESIGN
Prospective, randomized, controlled trial.
ANIMALS
5 clinically normal adult horses with chronically implanted gastric cannulas.
PROCEDURE
Each horse received all 5 treatments (30 g of aluminum hydroxide/15 g of magnesium hydroxide, 12 g of aluminum hydroxide/6 g of magnesium hydroxide, 10.5 g of bismuth subsalicylate, 26.25 g of bismuth subsalicylate, and 5% methylcellulose control) with only 1 experiment performed each day. Gastric pH was measured via a glass electrode inserted through the gastric cannula for 1 hour before treatment and continued for 2 hours after treatment. Food or water was not given to the horses during the experiment. Measurements of gastric pH obtained during posttreatment hours were compared with pretreatment gastric pH values.
RESULTS
Only a dose of 30 g of aluminum hydroxide/ 15 g of magnesium hydroxide resulted in a significant increase in gastric pH over baseline or control values. Mean pH was 5.2 +/- 0.62 and 4.59 +/- 0.48 for posttreatment hours 1 and 2, respectively.
CLINICAL IMPLICATIONS
Oral administration of 30 g of aluminum hydroxide/15 g of magnesium hydroxide to adult horses should result in a mean hourly gastric pH > or = 4.0 for at least 2 hours.
Topics: Administration, Oral; Aluminum Hydroxide; Animals; Antacids; Bismuth; Drug Therapy, Combination; Female; Gastric Acidity Determination; Gastric Mucosa; Horse Diseases; Horses; Hydrogen-Ion Concentration; Magnesium Hydroxide; Male; Organometallic Compounds; Peptic Ulcer; Prospective Studies; Salicylates; Stomach
PubMed: 8641951
DOI: No ID Found -
Magnesium hydroxide-based dentifrice as an anti-erosive agent in an in situ intrinsic erosion model.American Journal of Dentistry Jun 2017To evaluate in situ a magnesium hydroxide-[Mg(OH)2] based dentifrice on enamel erosion. (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
To evaluate in situ a magnesium hydroxide-[Mg(OH)2] based dentifrice on enamel erosion.
METHODS
Human dental enamel slabs were selected by surface microhardness and randomly assigned to one out of the following three groups (n=18): non-fluoride (control), NaF (1,450 ppm F), and Mg(OH)2 dentifrices. 18 volunteers were enrolled in a randomized, crossover and double-blind study, with three phases in 5 days. They wore acrylic palatal appliances containing two human enamel slabs, which were treated with one of the three dentifrices. During each experimental phase, the specimens were subjected to erosion by immersion in 0.01 M HCl for 60 seconds, 4x/day, followed by a 1-minute treatment with the correspondent slurry (saliva/dentifrice). Enamel changes were determined by the percentage of surface hardness loss (%SHL) and mechanical profilometry analysis. Data were analyzed by ANOVA, followed by Tukey's test (P< 0.05).
RESULTS
The means (SD) for %SHL and surface wear (μm) were, respectively, as follows: control [50.67(17.48), 2.70(1.24) ], NaF [45.45(15.44), 1.95(0.70) ] and Mg(OH)2 [53.94(19.48), 1.95(0.67) ]. There was no statistically significant difference among the treated and control groups for %SHL (P= 0.349); however, for wear rates, a statistically significant difference was found between the groups treated with NaF and Mg(OH)2 and the control group (P= 0.04).
CLINICAL SIGNIFICANCE
Dentifrices containing magnesium hydroxide or sodium fluoride might be an important strategy to minimize the effects of erosive challenges.
Topics: Adult; Cross-Over Studies; Dentifrices; Double-Blind Method; Female; Humans; Hydrochloric Acid; Magnesium Hydroxide; Male; Sodium Fluoride; Tooth Erosion; Treatment Outcome
PubMed: 29178758
DOI: No ID Found