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[PMID]: 28836872 [Au] Autor: Dettmar PW; Gil-Gonzalez D; Fisher J; Flint L; Rainforth D; Moreno-Herrera A; Potts M [Ad] Endereço: a Research Department , Technostics Limited, Castle Hill Hospital , Cottingham , UK. [Ti] Título: A comparative study on the raft chemical properties of various alginate antacid raft-forming products. [So] Source: Drug Dev Ind Pharm;44(1):30-39, 2018 Jan. [Is] ISSN: 1520-5762 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: OBJECTIVE: Research to measure the chemical characterization of alginate rafts for good raft performance and ascertain how formulation can affect chemical parameters. SIGNIFICANCE: A selection of alginate formulations was investigated all claiming to be proficient raft formers with significance between products established and ranked. METHODS: Procedures were selected which demonstrated the chemical characterization allowing rafts to effectively impede the reflux into the esophagus or in severe cases to be refluxed preferentially into the esophagus and exert a demulcent effect, with focus of current research on methods which complement previous studies centered on physical properties. The alginate content was analyzed by a newly developed HPLC method. Methods were used to determine the neutralization profile and the acid neutralization within the raft determined along with how raft structure affects neutralization. RESULTS: Alginate content of Gaviscon Double Action (GDA) within the raft was significantly superior (p < .0001) to all competitor products. The two products with the highest raft acid neutralization capacity were GDA and Rennie Duo, the latter product not being a raft former. Raft structure was key and GDA had the right level of porosity to allow for longer duration of neutralization. CONCLUSION: Alginate formulations require three chemical reactions to take place simultaneously: transformation to alginic acid, sodium carbonate reacting to form carbon dioxide, calcium releasing free calcium ions to bind with alginic acid providing strength to raft formation. GDA was significantly superior (p <.0001) to all other comparators. [Mh] Termos MeSH primário: Alginatos/química Hidróxido de Alumínio/química Antiácidos/química Carbonato de Cálcio/química Carbonatos/química Esôfago/química Refluxo Gastroesofágico/tratamento farmacológico Magnésio/química Ácido Silícico/química Bicarbonato de Sódio/química [Mh] Termos MeSH secundário: Alginatos/farmacologia Alginatos/uso terapêutico Antiácidos/metabolismo Antiácidos/uso terapêutico Combinação de Medicamentos Impedância Elétrica Refluxo Gastroesofágico/metabolismo Ácido Glucurônico/química Ácido Glucurônico/farmacologia Ácido Glucurônico/uso terapêutico Ácidos Hexurônicos/química Ácidos Hexurônicos/farmacologia Ácidos Hexurônicos/uso terapêutico Seres Humanos [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Alginates); 0 (Antacids); 0 (Carbonates); 0 (Drug Combinations); 0 (Hexuronic Acids); 1343-98-2 (Silicic Acid); 45P3261C7T (sodium carbonate); 5QB0T2IUN0 (Aluminum Hydroxide); 66220-44-8 (alginate, aluminium hydroxide, magnesium trisilicate, sodium bicarbonate drug combination); 82351-35-7 (Rennie); 8A5D83Q4RW (Glucuronic Acid); 8C3Z4148WZ (alginic acid); 8MDF5V39QO (Sodium Bicarbonate); H0G9379FGK (Calcium Carbonate); I38ZP9992A (Magnesium) [Em] Mês de entrada: 1801 [Cu] Atualização por classe: 180111 [Lr] Data última revisão: 180111 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170825 [St] Status: MEDLINE [do] DOI: 10.1080/03639045.2017.1371737

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[PMID]: 28464343 [Au] Autor: Coyle C; Crawford G; Wilkinson J; Thomas SJ; Bytzer P [Ad] Endereço: RB, Slough, Berkshire, UK. [Ti] Título: Randomised clinical trial: addition of alginate-antacid (Gaviscon Double Action) to proton pump inhibitor therapy in patients with breakthrough symptoms. [So] Source: Aliment Pharmacol Ther;45(12):1524-1533, 2017 06. [Is] ISSN: 1365-2036 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: BACKGROUND: Symptomatic breakthrough in proton pump inhibitor (PPI)-treated gastro-oesophageal reflux disease (GERD) patients is a common problem with a range of underlying causes. The nonsystemic, raft-forming action of alginates may help resolve symptoms. AIM: To assess alginate-antacid (Gaviscon Double Action, RB, Slough, UK) as add-on therapy to once-daily PPI for suppression of breakthrough reflux symptoms. METHODS: In two randomised, double-blind studies (exploratory, n=52; confirmatory, n=262), patients taking standard-dose PPI who had breakthrough symptoms, assessed by Heartburn Reflux Dyspepsia Questionnaire (HRDQ), were randomised to add-on Gaviscon or placebo (20 mL after meals and bedtime). The exploratory study endpoint was change in HRDQ score during treatment vs run-in. The confirmatory study endpoint was "response" defined as ≥3 days reduction in the number of "bad" days (HRDQ [heartburn/regurgitation] >0.70) during treatment vs run-in. RESULTS: In the exploratory study, significantly greater reductions in HRDQ scores (heartburn/regurgitation) were observed in the Gaviscon vs placebo (least squares mean difference [95% CI] -2.10 [-3.71 to -0.48]; P=.012). Post hoc "responder" analysis of the exploratory study also revealed significantly more Gaviscon patients (75%) achieved ≥3 days reduction in "bad" days vs placebo patients (36%), P=.005. In the confirmatory study, symptomatic improvement was observed with add-on Gaviscon (51%) but there was no significant difference in response vs placebo (48%) (OR (95% CI) 1.15 (0.69-1.91), P=.5939). CONCLUSIONS: Adding Gaviscon to PPI reduced breakthrough GERD symptoms but a nearly equal response was observed for placebo. Response to intervention may vary according to whether symptoms are functional in origin. [Mh] Termos MeSH primário: Alginatos/administração & dosagem Hidróxido de Alumínio/administração & dosagem Antiácidos/administração & dosagem Dor Irruptiva/tratamento farmacológico Refluxo Gastroesofágico/tratamento farmacológico Inibidores da Bomba de Prótons/administração & dosagem Ácido Silícico/administração & dosagem Bicarbonato de Sódio/administração & dosagem [Mh] Termos MeSH secundário: Adulto Idoso Alginatos/efeitos adversos Hidróxido de Alumínio/efeitos adversos Antiácidos/efeitos adversos Antiulcerosos/administração & dosagem Antiulcerosos/efeitos adversos Método Duplo-Cego Combinação de Medicamentos Feminino Azia/tratamento farmacológico Seres Humanos Masculino Meia-Idade Inibidores da Bomba de Prótons/efeitos adversos Ácido Silícico/efeitos adversos Bicarbonato de Sódio/efeitos adversos Resultado do Tratamento [Pt] Tipo de publicação: JOURNAL ARTICLE; MULTICENTER STUDY; RANDOMIZED CONTROLLED TRIAL; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Alginates); 0 (Antacids); 0 (Anti-Ulcer Agents); 0 (Drug Combinations); 0 (Proton Pump Inhibitors); 1343-98-2 (Silicic Acid); 5QB0T2IUN0 (Aluminum Hydroxide); 66220-44-8 (alginate, aluminium hydroxide, magnesium trisilicate, sodium bicarbonate drug combination); 8MDF5V39QO (Sodium Bicarbonate) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171220 [Lr] Data última revisão: 171220 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170503 [St] Status: MEDLINE [do] DOI: 10.1111/apt.14064

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[PMID]: 28799215 [Au] Autor: Zerfaß C; Buchko GW; Shaw WJ; Hobe S; Paulsen H [Ad] Endereço: Institute of Molecular Physiology, Johannes Gutenberg University, Johannes-von-Müller-Weg 6, Mainz, 55128, Germany. [Ti] Título: Secondary structure and dynamics study of the intrinsically disordered silica-mineralizing peptide P S during silicic acid condensation and silica decondensation. [So] Source: Proteins;85(11):2111-2126, 2017 Nov. [Is] ISSN: 1097-0134 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The silica forming repeat R5 of sil1 from Cylindrotheca fusiformis was the blueprint for the design of P S , a 50-residue peptide which can be produced in large amounts by recombinant bacterial expression. It contains 5 protein kinase A target sites and is highly cationic due to 10 lysine and 10 arginine residues. In the presence of supersaturated orthosilicic acid P S enhances silica-formation whereas it retards the dissolution of amorphous silica (SiO ) at globally undersaturated concentrations. The secondary structure of P S during these 2 processes was studied by circular dichroism (CD) spectroscopy, complemented by nuclear magnetic resonance (NMR) spectroscopy of the peptide in the absence of silicate. The NMR studies of dual-labeled ( C, N) P S revealed a disordered structure at pH 2.8 and 4.5. Within the pH range of 4.5-9.5 in the absence of silicic acid, the CD data showed a disordered structure with the suggestion of some polyproline II character. Upon silicic acid polymerization and during dissolution of preformed silica, the CD spectrum of P S indicated partial transition into an α-helical conformation which was transient during silica-dissolution. The secondary structural changes observed for P S correlate with the presence of oligomeric/polymeric silicic acid, presumably due to P S -silica interactions. These P S -silica interactions appear, at least in part, ionic in nature since negatively charged dodecylsulfate caused similar perturbations to the P S CD spectrum as observed with silica, while uncharged ß-d-dodecyl maltoside did not affect the CD spectrum of P S . Thus, with an associated increase in α-helical character, P S influences both the condensation of silicic acid into silica and its decondensation back to silicic acid. [Mh] Termos MeSH primário: Proteínas Intrinsicamente Desordenadas/química Proteínas Intrinsicamente Desordenadas/metabolismo Peptídeos/química Ácido Silícico/química Dióxido de Silício/química [Mh] Termos MeSH secundário: Simulação de Dinâmica Molecular Ressonância Magnética Nuclear Biomolecular Peptídeos/metabolismo Conformação Proteica Ácido Silícico/metabolismo Dióxido de Silício/metabolismo Cloreto de Sódio [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Intrinsically Disordered Proteins); 0 (Peptides); 1343-98-2 (Silicic Acid); 451W47IQ8X (Sodium Chloride); 7631-86-9 (Silicon Dioxide) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171030 [Lr] Data última revisão: 171030 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170812 [St] Status: MEDLINE [do] DOI: 10.1002/prot.25366

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[PMID]: 28333113 [Au] Autor: Shuai C; Shuai C; Feng P; Yang Y; Xu Y; Qin T; Yang S; Gao C; Peng S [Ad] Endereço: State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China. shuai@csu.edu.cn. [Ti] Título: Silane Modified Diopside for Improved Interfacial Adhesion and Bioactivity of Composite Scaffolds. [So] Source: Molecules;22(4), 2017 Mar 23. [Is] ISSN: 1420-3049 [Cp] País de publicação: Switzerland [La] Idioma: eng [Ab] Resumo: Diopside (DIOP) was introduced into polyetheretherketone/polyglycolicacid (PEEK/PGA) scaffolds fabricated via selective laser sintering to improve bioactivity. The DIOP surface was then modified using a silane coupling agent, 3-glycidoxypropyltrimethoxysilane (KH570), to reinforce interfacial adhesion. The results showed that the tensile properties and thermal stability of the scaffolds were significantly enhanced. It could be explained that, on the one hand, the hydrophilic group of KH570 formed an organic covalent bond with the hydroxy group on DIOP surface. On the other hand, there existed relatively high compatibility between its hydrophobic group and the biopolymer matrix. Thus, the ameliorated interface interaction led to a homogeneous state of DIOP dispersion in the matrix. More importantly, an in vitro bioactivity study demonstrated that the scaffolds with KH570-modified DIOP (KDIOP) exhibited the capability of forming a layer of apatite. In addition, cell culture experiments revealed that they had good biocompatibility compared to the scaffolds without KDIOP. It indicated that the scaffolds with KDIOP possess potential application in tissue engineering. [Mh] Termos MeSH primário: Silanos/síntese química Ácido Silícico/química [Mh] Termos MeSH secundário: Linhagem Celular Seres Humanos Silanos/química Propriedades de Superfície [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Silanes); 1343-98-2 (Silicic Acid); 14483-19-3 (diopside) [Em] Mês de entrada: 1705 [Cu] Atualização por classe: 170518 [Lr] Data última revisão: 170518 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170324 [St] Status: MEDLINE

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[PMID]: 28182119 [Au] Autor: Yang HY; Niu LN; Sun JL; Huang XQ; Pei DD; Huang C; Tay FR [Ad] Endereço: The State Key Laboratory Breeding Base of Basic Science of Stomatology, Key Laboratory for Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei, People's Republic of China. [Ti] Título: Biodegradable mesoporous delivery system for biomineralization precursors. [So] Source: Int J Nanomedicine;12:839-854, 2017. [Is] ISSN: 1178-2013 [Cp] País de publicação: New Zealand [La] Idioma: eng [Ab] Resumo: Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration. [Mh] Termos MeSH primário: Regeneração Óssea/efeitos dos fármacos Fosfatos de Cálcio/farmacologia Nanopartículas/química Osteogênese/efeitos dos fármacos Polímeros/química Dióxido de Silício/química [Mh] Termos MeSH secundário: Alilamina/química Animais Materiais Biocompatíveis/química Bovinos Diferenciação Celular/efeitos dos fármacos Colágeno/química Seres Humanos Nanopartículas/administração & dosagem Ácido Silícico/análise Engenharia Tecidual Tecidos Suporte [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Biocompatible Materials); 0 (Calcium Phosphates); 0 (Polymers); 0 (amorphous calcium phosphate); 1343-98-2 (Silicic Acid); 48G762T011 (Allylamine); 7631-86-9 (Silicon Dioxide); 9007-34-5 (Collagen) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 170404 [Lr] Data última revisão: 170404 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170210 [St] Status: MEDLINE [do] DOI: 10.2147/IJN.S128792

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[PMID]: 28056936 [Au] Autor: Geusens P; Pavelka K; Rovensky J; Vanhoof J; Demeester N; Calomme M; Vanden Berghe D [Ad] Endereço: Biomedical Research Institute (BIOMED), Hasselt University, Diepenbeek, Belgium. drpgeusens@gmail.com. [Ti] Título: A 12-week randomized, double-blind, placebo-controlled multicenter study of choline-stabilized orthosilicic acid in patients with symptomatic knee osteoarthritis. [So] Source: BMC Musculoskelet Disord;18(1):2, 2017 Jan 05. [Is] ISSN: 1471-2474 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: BACKGROUND: The aim of this study was to assess the efficacy of choline-stabilized orthosilicic acid (ch-OSA) in patients with symptomatic knee osteoarthritis (OA). METHODS: In a multicenter, double-blind, placebo-controlled study, 211 patients with knee OA (Kellgren and Lawrence grade II or III) and moderate to moderately severe pain were randomly allocated to ch-OSA or placebo for 12 weeks. The primary outcome was the change in the WOMAC pain subscale from baseline to week 12. Secondary outcomes were changes from baseline to week 12 in WOMAC total, WOMAC stiffness, WOMAC physical function, Subject Global Assessment and levels of cartilage degradation biomarkers C-terminal telopeptide of collagen type II (CTX-II) and cartilage oligomeric matrix protein (COMP). Pre-specified subgroup analyses included the effect of gender. RESULTS: A total of 166 (120 women, 46 men) patients were included in the analysis (87 and 79 in the ch-OSA and placebo group, respectively). In the total study population, no differences were observed between the two treatment groups for the different outcomes but significant treatment x gender interactions were found. In men taking ch-OSA, a significant improvement in WOMAC total, WOMAC stiffness and WOMAC physical function as well as a lower increase in biomarker levels of cartilage degradation was observed, but not in women. The change in WOMAC pain showed a similar positive trend in men taking ch-OSA. CONCLUSION: After 12 weeks of treatment, no effect was found of ch-OSA in the total study population on clinical parameters and biomarkers, but a gender interaction was observed. In men, ch-OSA was found effective in reducing symptoms of knee OA, which was associated with a slight but significant reduction of biomarkers that are related to cartilage degradation. TRIAL REGISTRATION: The study was registered retrospectively: ISRCTN88583133 . Registration date: 2015-10-07. [Mh] Termos MeSH primário: Proteína de Matriz Oligomérica de Cartilagem/análise Colina/uso terapêutico Colágeno Tipo II/análise Osteoartrite do Joelho/tratamento farmacológico Manejo da Dor/métodos Ácido Silícico/uso terapêutico [Mh] Termos MeSH secundário: Administração Oral Idoso Biomarcadores/análise Cartilagem/patologia Colina/administração & dosagem Método Duplo-Cego Feminino Seres Humanos Masculino Meia-Idade Medição da Dor Fatores Sexuais Ácido Silícico/administração & dosagem Resultado do Tratamento [Pt] Tipo de publicação: JOURNAL ARTICLE; MULTICENTER STUDY; RANDOMIZED CONTROLLED TRIAL [Nm] Nome de substância: 0 (Biomarkers); 0 (Cartilage Oligomeric Matrix Protein); 0 (Collagen Type II); 1343-98-2 (Silicic Acid); N91BDP6H0X (Choline) [Em] Mês de entrada: 1709 [Cu] Atualização por classe: 170926 [Lr] Data última revisão: 170926 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170107 [St] Status: MEDLINE [do] DOI: 10.1186/s12891-016-1370-7

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[PMID]: 28044217 [Au] Autor: Ding T; Zhang J; Ni W; Li J [Ad] Endereço: College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China. dingtengda@zju.edu.cn. [Ti] Título: Combined toxicity of arsenite and dimethylarsenic acid on the freshwater diatom Nitzschia palea. [So] Source: Ecotoxicology;26(2):202-210, 2017 Mar. [Is] ISSN: 1573-3017 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The toxicity and bioavailability of single arsenic species have been widely investigated, however, the biological effects of mixed arsenic species co-existing in natural waters still remain unknown. The objective of this work was to discern the adverse effects of combined arsenite (As(III)) and dimethylarsenic acid (DMA) on diatom Nitzschia palea. The combined ecotoxicity of As(III) and DMA on N. palea was observed to be time-dependent and showed dose-effect relation. The toxicity of DMA and As(III) mixture was higher than individual DMA or As(III) when the As(III) concentration was in the range of 0.085-0.316 mg L . As the As(III) concentration increased from 0.487 to 0.858 mg L , the antagonistic effect was found, which could be due to the higher thiols contents in the thiol-containing proteins (e.g., frustulins, silaffins and other glycoproteins). The content of malondialdehyde (MDA) in the treatment of mixed arsenic species was found to be at the same level compared to the As-free control after 72 h of exposure, indicating that the co-toxicity of As(III) and DMA on diatom frustules was not significant. Furthermore, the increase of frustule formation rate in the mixture of EC As(III)-EC DMA at 72 h exposure time indicated that the damaged diatom cell walls was likely repaired gradually. The results from this study suggested that the effects of co-existed arsenic species were concentration-specific and should be considered in the risk assessment of arsenic and development of water quality criteria for the protection of aquatic ecosystems. [Mh] Termos MeSH primário: Arsenitos/toxicidade Ácido Cacodílico/toxicidade Diatomáceas/efeitos dos fármacos Ácido Silícico/toxicidade [Mh] Termos MeSH secundário: Poluentes Químicos da Água/toxicidade [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Arsenites); 0 (Water Pollutants, Chemical); 1343-98-2 (Silicic Acid); AJ2HL7EU8K (Cacodylic Acid); N5509X556J (arsenite) [Em] Mês de entrada: 1703 [Cu] Atualização por classe: 171019 [Lr] Data última revisão: 171019 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170104 [St] Status: MEDLINE [do] DOI: 10.1007/s10646-016-1755-2

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[PMID]: 28024584 [Au] Autor: Najafinezhad A; Abdellahi M; Ghayour H; Soheily A; Chami A; Khandan A [Ad] Endereço: Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. [Ti] Título: A comparative study on the synthesis mechanism, bioactivity and mechanical properties of three silicate bioceramics. [So] Source: Mater Sci Eng C Mater Biol Appl;72:259-267, 2017 Mar 01. [Is] ISSN: 1873-0191 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: In the present study three akermanite (Ca MgSi O ), diopside (CaMgSi O ) and baghdadite (Ca ZrSi O ) applicable bioceramics were synthesized via a sol-gel based method. The combination of sol-gel method and the raw materials used in this study presents a new route for the synthesis of the mentioned bioceramics. By the use of thermal analysis, the mechanisms occurred during the synthesis of these bioceramics were investigated. The differences in the structural density and their relation with the degradation rate and mechanical properties of all three ceramics were studied. In vitro bioactivity and apatite formation mechanisms of the samples soaked in the simulated body fluid were considered. The results showed that baghdadite as a Zr-containing material has a more dense structure in comparison with the other ceramics, which leads to a lower degradation rate and also lower bioactivity. There were also main differences between akermanite and diopside as Mg-containing ceramics. Diopside showed a structure with lower porosity content compared to the akermanite samples which resulted in the lower degradation rate and higher compressive strength. [Mh] Termos MeSH primário: Materiais Biocompatíveis/química Cerâmica/química Silicatos/química Ácido Silícico/química [Mh] Termos MeSH secundário: Materiais Biocompatíveis/síntese química Géis/química Microscopia Eletrônica de Varredura Nanoestruturas/química Espectroscopia de Infravermelho com Transformada de Fourier Difração de Raios X [Pt] Tipo de publicação: COMPARATIVE STUDY; JOURNAL ARTICLE [Nm] Nome de substância: 0 (Biocompatible Materials); 0 (Ca(3)ZrSi(2)O(9)); 0 (Gels); 0 (Silicates); 1343-98-2 (Silicic Acid); 14483-19-3 (diopside); 85422-94-2 (Glass ceramics) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 170420 [Lr] Data última revisão: 170420 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161228 [St] Status: MEDLINE

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[PMID]: 28017870 [Au] Autor: Fiocco L; Li S; Stevens MM; Bernardo E; Jones JR [Ad] Endereço: Dipartimento di Ingegneria Industriale, University of Padova, Via Marzolo, 9, 35131 Padova, Italy. [Ti] Título: Biocompatibility and bioactivity of porous polymer-derived Ca-Mg silicate ceramics. [So] Source: Acta Biomater;50:56-67, 2017 Mar 01. [Is] ISSN: 1878-7568 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Magnesium is a trace element in the human body, known to have important effects on cell differentiation and the mineralisation of calcified tissues. This study aimed to synthesise highly porous Ca-Mg silicate foamed scaffolds from preceramic polymers, with analysis of their biological response. Akermanite (Ak) and wollastonite-diopside (WD) ceramic foams were obtained from the pyrolysis of a liquid silicone mixed with reactive fillers. The porous structure was obtained by controlled water release from selected fillers (magnesium hydroxide and borax) at 350°C. The homogeneous distribution of open pores, with interconnects of modal diameters of 160-180µm was obtained and maintained after firing at 1100°C. Foams, with porosity exceeding 80%, exhibited compressive strength values of 1-2MPa. In vitro studies were conducted by immersion in SBF for 21days, showing suitable dissolution rates, pH and ionic concentrations. Cytotoxicity analysis performed in accordance with ISO10993-5 and ISO10993-12 standards confirmed excellent biocompatibility of both Ak and WD foams. In addition, MC3T3-E1 cells cultured on the Mg-containing scaffolds demonstrated enhanced osteogenic differentiation and the expression of osteogenic markers including Collagen Type I, Osteopontin and Osteocalcin, in comparison to Mg-free counterparts. The results suggest that the addition of magnesium can further enhance the bioactivity and the potential for bone regeneration applications of Ca-silicate materials. STATEMENTS OF SIGNIFICANCE: Here, we show that the incorporation of Mg in Ca-silicates plays a significant role in the enhancement of the osteogenic differentiation and matrix formation of MC3T3-E1 cells, cultured on polymer-derived highly porous scaffolds. Reduced degradation rates and improved mechanical properties are also observed, compared to Mg-free counterparts, suggesting the great potential of Ca-Mg silicates as bone tissue engineering materials. Excellent biocompatibility of the new materials, in accordance to the ISO10993-5 and ISO10993-12 standard guidelines, confirms the preceramic polymer route as an efficient synthesis methodology for bone scaffolds. The use of hydrated fillers as porogens is an additional novelty feature presented in the manuscript. [Mh] Termos MeSH primário: Compostos de Cálcio Cerâmica Silicatos de Magnésio Teste de Materiais Silicatos [Mh] Termos MeSH secundário: Animais Antígenos de Diferenciação/biossíntese Compostos de Cálcio/química Compostos de Cálcio/farmacologia Diferenciação Celular/efeitos dos fármacos Linhagem Celular Sobrevivência Celular/efeitos dos fármacos Cerâmica/síntese química Cerâmica/química Cerâmica/farmacologia Força Compressiva Silicatos de Magnésio/química Silicatos de Magnésio/farmacologia Camundongos Porosidade Silicatos/química Silicatos/farmacologia Ácido Silícico/química Ácido Silícico/farmacologia [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antigens, Differentiation); 0 (Calcium Compounds); 0 (Magnesium Silicates); 0 (Silicates); 1343-88-0 (Florisil); 1343-98-2 (Silicic Acid); 14483-19-3 (diopside); 85422-94-2 (Glass ceramics); S4255P4G5M (calcium silicate) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171030 [Lr] Data última revisão: 171030 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161227 [St] Status: MEDLINE

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MEDLINE

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[PMID]: 27987751 [Au] Autor: Kazemi A; Abdellahi M; Khajeh-Sharafabadi A; Khandan A; Ozada N [Ad] Endereço: Advanced Materials Research Center, Department of Materials Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran. [Ti] Título: Study of in vitro bioactivity and mechanical properties of diopside nano-bioceramic synthesized by a facile method using eggshell as raw material. [So] Source: Mater Sci Eng C Mater Biol Appl;71:604-610, 2017 Feb 01. [Is] ISSN: 1873-0191 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: In this study, diopside bioceramic was synthesized using a mechanical milling process and subsequent heat treatment. The simplicity of experiments and also the high energy available in ball milling lead to rapid synthesis of the products in comparison with other synthesis methods. Magnesium oxide (MgO), silicon dioxide (SiO ) and eggshell (as the calcium source) powders were weighted in stoichiometric conditions and milled to initial activation of the surface of the powder's mixture. Then a sintering process was conducted to complete formation of diopside nanopowder and also evaluates its thermal stability. The mechanisms occurred during the synthesis of this bioceramic were carefully investigated. X-Ray diffraction analysis (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry (TG), differential thermal analysis (DTA), and inductive coupled plasma atomic emission spectroscopy (ICP-AES) were used for gathering and analyzing data. The ability and rate of apatite formation on the sample surface were evaluated by Simulated Body Fluid (SBF) test, a method that is well recognized to characterize the in vitro bioactivity of ceramic materials. According to the results obtained, the diopside samples had a significant potential to form apatite layer on their surface during soaking in the SBF solution. Besides, the bonding strength of this bioceramic was about 350±7MPa which was almost more than three times of that reported for hydroxyapatite. An excellent fracture toughness of 4±0.3MPam was also obtained for this ceramic which was higher than that of previously reported works. [Mh] Termos MeSH primário: Cerâmica Casca de Ovo/química Nanoestruturas/química Ácido Silícico [Mh] Termos MeSH secundário: Animais Cerâmica/síntese química Cerâmica/química Nanoestruturas/ultraestrutura Ácido Silícico/síntese química Ácido Silícico/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 1343-98-2 (Silicic Acid); 14483-19-3 (diopside) [Em] Mês de entrada: 1704 [Cu] Atualização por classe: 170926 [Lr] Data última revisão: 170926 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 161219 [St] Status: MEDLINE

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