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559 result(s) for "Silicates - pharmacology"
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Dislodgement resistance and structural changes of tricalcium silicate-based cements after exposure to different chelating agents
This study aimed to evaluate the dislodgement resistance and structural changes of different mineral trioxide aggregate cements (MTA) like Pro-Root MTA, Ortho MTA, and Retro MTA after exposure to sodium hypochlorite (NaOCl), NaOCl-Ethylenediaminetetraacetic acid (EDTA), 1-hydroxyethylidene-1, 1-bisphosphonate (Dual Rinse HEDP), and NaOCl-Maleic acid (MA). The root canal spaces of 150 dentine slices were obturated using tricalcium silicate cements and divided into 3 groups (n = 50): Group1: ProRoot MTA, Group2: Retro MTA, and Group3: Ortho MTA. The samples in each group were further subdivided into four experimental (n = 10) and one control groups (n = 10): 2.5% NaOCl-17% EDTA, Dual Rinse HEDP, 2.5% NaOCl-7% Maleic acid, 2.5% NaOCl, distilled water (control). The dislodgement resistance and structural changes of cements were measured. Use of DR HEDP resulted in higher dislodgement resistance compared to17% EDTA and 7% MA in the samples obturated with Ortho MTA and Pro-Root MTA (p<0.001). In Retro MTA group, samples treated with DR HEDP and 17% EDTA had higher dislodgment resistance compared to 7% MA (p<0.001). On microstructural and elemental analysis of all the three MTA cements, samples treated with 17% EDTA and 7% MA were more amorphous and granular when compared to DR HEDP, which was pettle shaped. Calcium level was decreased more in samples treated with 17% EDTA and 7% MA when compared to DR HEDP.
Beneficial modulation of the gut microbiome by leachates of Penicillium purpurogenum in the presence of clays: A model for the preparation and efficacy of historical Lemnian Earth
The experiments presented here are based on the reconfiguration of an ancient medicine, Lemnian Earth (LE) ( terra sigillata , stamped earth , sphragis ), an acclaimed therapeutic clay with a 2500-year history of use. Based on our hypothesis that LE was not a natural material but an artificially modified one involving a clay-fungus interaction, we present results from experiments involving the co-culture of a common fungus, Penicillium purpurogenum ( Pp ), with two separate clay slurries, smectite and kaolin, which are the principal constituents of LE. Our results show: (a) the leachate of the Pp +smectite co-culture is antibacterial in vitro , inhibiting the growth of both Gram-positive and Gram-negative bacteria; (b) in vivo , supplementation of regular mouse diet with leachates of Pp +smectite increases intestinal microbial diversity; (c) Pp+ kaolin does not produce similar results; (d) untargeted metabolomics and analysis of bacterial functional pathways indicates that the Pp +smectite-induced microbiome amplifies production of short-chain fatty acids (SCFAs) and amino acid biosynthesis, known to modulate intestinal and systemic inflammation. Our results suggest that the combination of increased microbial diversity and SCFA production indicates beneficial effects on the host microbiome, thus lending support to the argument that the therapeutic properties of LE may have been based on the potential for modulating the gut microbiome. Our experiments involving reconfigured LE open the door to future research into small molecule-based sources for promoting gut health.
The effect of acidity on the physicochemical properties of two hydraulic calcium silicate-based cements and two calcium phosphate silicate-based cements
Background Bioceramic cements have been widely used in endodontic treatment. This study aimed to compare the microhardness, elastic modulus, internal microstructure and chemical compositions of Biodentine, WMTA, ERRM Putty, iRoot FS and IRM after exposure to PBS, butyric acid, and butyric acid followed by PBS. Methods Specimens of each material were prepared and randomly divided into 5 subgroups (n = 5): subgroup A: PBS (pH = 7.4) for 4 days, subgroup B: PBS (pH = 7.4) for 14 days, subgroup C: butyric acid (pH = 5.4) for 4 days, subgroup D: butyric acid (pH = 5.4) for 14 days, subgroup E: butyric acid for 4 days followed by 10 days in contact with PBS. The surface microhardness, elastic modulus, internal morphologic and chemical compositions of specimens were analyzed. Results The microhardness and elastic modulus values of all materials were significantly higher in the presence of PBS compared to exposure to butyric acid, with the same setting time ( P  < 0.01). After 4-day exposure to butyric acid followed by 10-day exposure to PBS, the microhardness values returned to the same level as 4-day exposure to PBS ( P  > 0.05). Biodentine showed significantly higher microhardness and elastic modulus values than other materials, while IRM displayed the lowest ( P  < 0.01). Conclusion Biodentine seems the most suitable bioceramic cements when applied to an infected area with acidic pH. Further storage at neutral pH, e.g. PBS reverses the adverse effects on bioceramic cements caused by a low pH environment.
Antimicrobial effect of bioceramic cements on multispecies microcosm biofilm: a confocal laser microscopy study
ObjectivesTo assess the viability of multispecies microcosm biofilm after contact with NeoMTA Plus, Biodentine, and MTA Angelus.Materials and methodsFifty-four human dentin blocks (4 × 5 × 4 mm) were allocated to Hawley retainers, worn by six volunteers for 72 h. The blocks were then individually incubated in BHI broth for 21 days at 37 °C. At the end of experimental time for biofilm growth, the samples were randomly divided into four groups (n = 12): NeoMTA Plus, Biodentine, MTA Angelus, and negative control. The materials were placed in contact with the blocks. All samples were placed in cell-culture plate wells and incubated in BHI broth for 7 days at 37 °C. One sample from each volunteer (n = 6) was analyzed by SEM to describe the biofilm morphology. CLSM was performed to determine the percentage of viable biofilm biovolume. The data were statistically analyzed by one-way ANOVA and Tukey’s multiple comparison test (α = 5%).ResultsSEM showed biofilm formed by spherical and rod-shaped bacteria surrounded by an extracellular matrix. No material was able to kill all biofilm cells, and all groups had more than 50% of viable bacteria. NeoMTA Plus was significantly different from the negative control group (P < .05).ConclusionsAll tested materials were not effective against multispecies microcosm biofilm.Clinical relevanceNeoMTA Plus, Biodentine, and MTA Angelus were not effective against multispecies microcosm biofilm. It is essential to understand that these bioceramic cements are indicated for infected clinical situations. Thus, complementary disinfection procedures should be conducted prior to filling with these materials.
MicroRNA-146a-loaded magnesium silicate nanospheres promote bone regeneration in an inflammatory microenvironment
Reconstruction of irregular oral-maxillofacial bone defects with an inflammatory microenvironment remains a challenge, as chronic local inflammation can largely impair bone healing. Here, we used magnesium silicate nanospheres (MSNs) to load microRNA-146a-5p (miR-146a) to fabricate a nanobiomaterial, MSN+miR-146a, which showed synergistic promoting effects on the osteogenic differentiation of human dental pulp stem cells (hDPSCs). In addition, miR-146a exhibited an anti-inflammatory effect on mouse bone marrow-derived macrophages (BMMs) under lipopolysaccharide (LPS) stimulation by inhibiting the NF-κB pathway via targeting tumor necrosis factor receptor-associated factor 6 (TRAF6), and MSNs could simultaneously promote M2 polarization of BMMs. MiR-146a was also found to inhibit osteoclast formation. Finally, the dual osteogenic-promoting and immunoregulatory effects of MSN+miR-146a were further validated in a stimulated infected mouse mandibular bone defect model via delivery by a photocuring hydrogel. Collectively, the MSN+miR-146a complex revealed good potential in treating inflammatory irregular oral-maxillofacial bone defects.
Histopathological and immunohistochemical characterization of pulp tissue reaction to ACTIVA BioACTIVE base/liner in primary teeth pulpotomy: a randomized clinical trial
Background Mineral trioxide aggregate (MTA) is the gold standard pulpotomy agent with some shortcomings, such as lengthy setting time, difficult manipulation, and a costly price. A new bioactive material, ACTIVA BioACTIVE Base/Liner, may prevail over these drawbacks. Aim The purpose of the study was to evaluate and compare the pulp reaction in primary teeth to ACTIVA BioACTIVE Base/Liner and conventional powder-liquid MTA (WhiteProRoot®MTA) as pulpotomy agents. Materials and methods Eighty primary first molars in children aged 7–9 years were assigned into two groups (40 molars/group) in which the pulpotomy procedure was done. The pulp tissue was dressed in ACTIVA BioACTIVE Base/Liner (group I) and MTA (group II). Twenty teeth from each group were extracted after 15 days, and the remaining twenty teeth in each group were extracted after 30 days. All teeth specimens underwent a decalcification treatment for histological and immunohistochemical assessment for fibronectin and osteopontin (OPN) expressions. Results Significant statistical differences were identified between ACTIVA BioACTIVE and MTA groups concerning the total scoring of pulp vascularity, pulp fibrosis, and presence or absence of pulp stone ( P  = 0.015, P  < 0.001, P  = 0.038, respectively), whereas a non-significant difference was noted concerning the odontoblastic layer organization. Fibronectin and OPN in both ACTIVA BioACTIVE and MTA groups were positive at the fibrotic and calcified areas. Conclusion ACTIVA BioACTIVE Base/Liner demonstrated encouraging outcomes concerning enhanced systemic tissue responses. Trial Registration ClinicalTrials.gov, NCT05300152, “Pulpotomy Medications in Primary Teeth”, Registered: 29/03/2022, https://clinicaltrials.gov/study/NCT05300152?cond=NCT05300152&rank=1
Exploring the potential of phyllosilicate minerals as potassium fertilizers using sodium tetraphenylboron and intensive cropping with perennial ryegrass
In response to addressing potassium (K) deficiency in soil and decreasing agricultural production costs, the potential of K-bearing phyllosilicate minerals that can be directly used as an alternative K source has been investigated using sodium tetraphenylboron (NaTPB) extraction and an intensive cropping experiment. The results showed that the critical value of K-release rate and leaf K concentration was 3.30 g kg −1 h −1 and 30.64 g (kg dry matter) −1 , respectively under the experimental conditions. According to this critical value, the maximum amount of released K that could be utilized by a plant with no K deficiency symptoms was from biotite (27.80 g kg −1 ) and vermiculite (5.58 g kg −1 ), followed by illite, smectite and muscovite with 2.76, 0.88 and 0.49 g kg −1 , respectively. Ryegrass grown on phlogopite showed K deficiency symptoms during the overall growth period. It is concluded that biotite and vermiculite can be directly applied as a promising and sustainable alternative to the use of classical K fertilizers, illite can be utilized in combination with soluble K fertilizers, whereas muscovite, phlogopite and smectite may not be suitable for plant growth. Further field experiments are needed to assess the use of these phyllosilicate minerals as sources of K fertilizer.
Acute effects of Nitrosigine® and citrulline malate on vasodilation in young adults
Background Athletes are increasingly exploring ways to enhance their physical performance. Increasing blood flow to the working tissues through endothelium-dependent vasodilation is one factor athletes use to realize these results. Sports supplements such as pre-workouts tout this benefit; however, many have not been tested under laboratory conditions to examine the effects of commonly used supplements on vasodilation. Two popular supplements are Nitrosigine® and citrulline malate (CM). Thus, the purpose of this experiment was to determine the effects of Nitrosigine and CM on vasodilation using ultrasound and flow mediated dilation (FMD). Methods Healthy, normotensive, and physically active male ( n  = 16) and female ( n  = 8) young adults participated in the present investigation. We utilized a randomized, double-blind, within-subjects design where participants reported for three trials, each preceded by a 7-day washout period. Baseline FMD measurement was obtained for each visit, followed by consumption of one clinical dose CM (8 g), Nitrosigine (1.5 g), or dextrose placebo (8 g). Following a 60-min digestion period, FMD was repeated. Supplementation order was randomized controlling for potential order effects. Results Repeated measures ANOVA yielded a significant supplement (3) x time (2) effect ( p  < .001), such that Nitrosigine and CM yielded a greater improvement in FMD response than placebo. After supplementation, Nitrosigine and CM increased FMD by 31 and 34%, respectively, compared to a decrease of 2% during the placebo trial. After allometric scaling of the FMD values, supplement x time effect remained significant ( p  = .001) and changes were similar to non-scaled results. Nitrosigine (23%) and CM (25%) generated significantly greater allometric scaled FMD values when compared to the placebo trial (0.60%). Discussion Both Nitrisigine and CM increased endothelial-dependent vasodilation as measured by a change in FMD. Increased vasodilation leads to an increase in skeletal muscle blood flow resulting in potential improvements in exercise performance.
Mitigation of Colitis with NovaSil Clay Therapy
Background/Aims Five million people currently live with Crohn’s disease (CD) or ulcerative colitis, the two major forms of inflammatory bowel disease. Available treatments frequently result in side effects that compromise the immune health of the patient. Consequently, alternative therapies that cause fewer systemic effects are needed. Dioctahedral smectite clays have been utilized to treat medical conditions, including diarrheal and enteric disease. Herein, we report the ability of a refined dioctahedral smectite (NovaSil, NS) to sorb inflammatory proteins and reduce inflammation in a TNBS (2,4,6-trinitrobenzenesulfonic acid) mouse model of CD. We also investigated whether NS could rescue gut microbial diversity in TNBS-induced mice. Methods ELISA, X-ray diffraction, and transmission electron microscopy were employed to characterize the NS–cytokine interaction in vitro. A TNBS mouse colitis model was utilized to study the efficacy of NS supplementation for 4 weeks. The three treatment groups included control, TNBS, and TNBS + NS. DNA was extracted from feces and sorted for bacterial phylogenetic analysis. Results Results suggest that NS binds TNFα in vitro. In TNBS-treated mice, supplementation with NS significantly reduced weight loss, and serum proinflammatory cytokine levels (IL-2, IL-6, and IL-12, TNFα, IFNγ) compared with the TNBS group. TNBS-treated mice demonstrated a significant reduction in gut microbiota species richness when compared with the TNBS + NS group and control group. Conclusions NovaSil mitigated the effects of TNBS-induced colitis based on reduction in systemic markers of inflammation, significant improvement in weight gain, and intestinal microbial profile.
Effect of nanoparticulate CaCO 3 on the biological properties of calcium silicate cement
This study aimed to evaluate the effects of nanoparticulate CaCO (NPCC) on the biological properties of calcium silicate-based cements (CSCs), including their cytotoxicity, in vitro osteogenic activity, and interactions with rat femur tissue. The average size of NPCC was 90.3±26.0 nm. Cytotoxicity and osteogenic activity assays were performed using mouse bone marrow mesenchymal stem cells (BMSCs). BMSCs exposed to the eluents from CSC alone and CSC containing 2.5% NPCC (CSC-NPCC (2.5%)) for 24 h showed decreased cell viability at an eluent concentration of 75%. In contrast, CSC-NPCCs (5%, 10%, and 20%) did not affect cell viability. Regarding osteogenic activity, CSC-NPCCs (5%, 10%, 20%) enhanced the expression of osteogenic genes, including runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), type I collagen (COL-1), and osteocalcin (OCN). Additionally, mineralization in cell cultures was enhanced by CSC-NPCC, indicating that NPCC promoted the osteogenic activity of CSCs. In rat femurs, NPCC accelerates CSC resorption and stimulates bone regeneration at the implantation site. CSC alone occupied 22.2%±3.25% of the total femoral area at the implantation site, whereas CSC-NPCC (20%) occupied only 4%. These histological findings suggest that CSC-NPCC has potential as a biodegradable bone cement for use in bone defect areas that require regeneration.