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1.
J Appl Oral Sci ; 28: e20190105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31800873

RESUMO

Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use aiming at periapical tissue repair. However, its effects on dental pulp cells have been poorly explored. OBJECTIVE: This study assessed the impact of calcium chloride (CaCl2) and bismuth oxide (Bi2O3) or zinc oxide (ZnO) additives on odontoblast cell response to CAC. METHODOLOGY: MDPC-23 cells were exposed for up to 14 d: 1) CAC with 2.8% CaCl2 and 25% ZnO (CACz); 2) CAC with 2.8% CaCl2 and 25% Bi2O3 (CACb); 3) CAC with 10% CaCl2 and 25% Bi2O3 (CACb+); or 4) mineral trioxide aggregate (MTA), placed on inserts. Non-exposed cultures served as control. Cell morphology, cell viability, gene expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), and dentin matrix protein 1 (DMP-1), ALP activity, and extracellular matrix mineralization were evaluated. Data were compared using ANOVA (α=5%). RESULTS: Lower cell density was detected only for MTA and CACb+ compared with Control, with areas showing reduced cell spreading. Cell viability was similar among groups at days one and three (p>0.05). CACb+ and MTA showed the lowest cell viability values at day seven (p>0.05). CACb and CACb+ promoted higher ALP and BSP expression compared with CACz (p<0.05); despite that, all cements supported ALP activity. Matrix mineralization were enhanced in CACb+ and MTA. CONCLUSION: In conclusion, CAC with Bi2O3, but not with ZnO, supported the expression of odontoblastic phenotype, but only the composition with 10% CaCl2 promoted mineralized matrix formation, rendering it suitable for dentin-pulp complex repair.


Assuntos
Compostos de Alumínio/química , Compostos de Alumínio/farmacologia , Compostos de Cálcio/química , Compostos de Cálcio/farmacologia , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Fosfatase Alcalina/análise , Fosfatase Alcalina/efeitos dos fármacos , Animais , Bismuto/química , Bismuto/farmacologia , Cloreto de Cálcio/química , Cloreto de Cálcio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Combinação de Medicamentos , Expressão Gênica/efeitos dos fármacos , Teste de Materiais , Camundongos , Odontoblastos/efeitos dos fármacos , Óxidos/química , Óxidos/farmacologia , Reprodutibilidade dos Testes , Silicatos/química , Silicatos/farmacologia , Fatores de Tempo , Óxido de Zinco/química , Óxido de Zinco/farmacologia
2.
Chemosphere ; 239: 124738, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494316

RESUMO

Stabilization/Solidification (S/S) has been widely used in soil remediation to both improve physical properties and immobilize extensive contaminants. GGBS (granulated ground blast furnace slag)-MgO-CaO (GMCs) was used to treat Pb/Zn contaminated soil. The physical and microstructural characteristics of stabilized/solidified contaminated soil were investigated in this study. Microstructural analysis showed that the main hydration products of GMC treated contaminated soil were C-S-H and hydrotalcite like gels (Ht), which dominated the physical strength of S/S soil. The unconfined compressive strength (UCS) and the leachability of GMC treated contaminated soil were improved with the increase in GMC proportion (5%-15%), curing time (7 days and 28 days) and temperature (5 °C, 21 °C and 45 °C) due to the enhanced hydration. The compressive strengths of the majority mixes met the US EPA criterion (0.35 MPa). The strength of S/S soils was less affected by the increase of curing temperature after a longer curing period (28 days). According to the XRD and SEM results, both Pb and Zn in S/S contaminated soil could be immobilized by the precipitation and the adsorption on the surface of calcium silicate hydrate (C-S-H). Zn can also be incorporated into the structure of C-S-H and Ht. The addition of Pb/Zn decreased the physical strength in the order of: Pb(5000 mg/kg)>Pb(10000 mg/kg)>Zn/Pb(5000 mg/kg)>Pb(20000 mg/kg).


Assuntos
Recuperação e Remediação Ambiental/métodos , Chumbo/química , Poluentes do Solo/química , Solo/química , Zinco/química , Hidróxido de Alumínio/química , Compostos de Cálcio/química , China , Hidróxido de Magnésio/química , Óxido de Magnésio/química , Microscopia Eletrônica de Varredura , Óxidos/química , Silicatos/química , Temperatura Ambiente , Difração de Raios X
3.
Environ Int ; 133(Pt B): 105247, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31677577

RESUMO

Elevated level of arsenic (As) in marine sediment via deposition and accumulation presents long-term ecological risks. This study proposed a sustainable stabilization/solidification (S/S) of As-contaminated sediment via novel valorization of red mud waste, blast furnace slag and calcined clay mineral, which were selected to mitigate the increased leaching of As under alkaline environment of S/S treatment. Quantitative X-ray diffraction and thermogravimetric analyses illustrated that stable Ca-As complexes (e.g., Ca5(AsO4)3OH) could be formed at the expense of Ca(OH)2 consumption, which inevitably hindered the hydration process and S/S efficiency. The 29Si nuclear magnetic resonance analysis revealed that incorporation of metakaolin for As immobilization resulted in a low degree of hydration and polymerization, whereas addition of red mud promoted Fe-As complexation and demonstrated excellent compatibility with As. Transmission electron microscopy and elemental mapping further confirmed the precipitation of crystalline Ca-As and amorphous Fe-As compounds. Therefore, red mud-incorporated S/S binder achieved the highest efficiency of As immobilization (99.9%), which proved to be applicable for both in-situ and ex-situ S/S of As-contaminated sediment. These results advance our mechanistic understanding for the design of green and sustainable remediation approach for effective As immobilization.


Assuntos
Arsênico/química , Compostos de Cálcio/química , Argila/química , Sedimentos Geológicos/química , Resíduos Industriais , Mineração , Silicatos/química , Recuperação e Remediação Ambiental , Química Verde , Hong Kong , Humanos , Difração de Raios X
4.
Chem Pharm Bull (Tokyo) ; 67(10): 1152-1159, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582635

RESUMO

Melt adsorption is a manufacturing method that offers precise control of particle size distribution of granules and circumvents the disadvantages of conventional melt granulation. However, drug release from particles adsorbed with hydrophobic materials has not been fully investigated, and there are missing details as to whether particles manufactured by this technique can be applied to orally disintegrating tablets (ODT). In this report, we aimed to optimize process parameters and formulation to manufacture ODT containing melt adsorption-particles with the specific characteristic of sustained release. Melt adsorption particles containing Neusilin US2 as the adsorbent were prepared by using various waxes to determine the most suitable material for controlled release formulation. Glycerol fatty acid ester (Poem TR-FB: TR-FB) was the optimal wax examined because of its drug release pattern and tabletability. We then optimized manufacturing conditions by examining granulation time, disintegrant amount per tablet and compression force on the tablet for ODT that meet the criteria of controlled drug release, tensile strength and disintegration of the tablet. Multiple regression analysis revealed the effect of process parameters on tablet properties and drug release with increasing the granulation time affording sustained release of the drug. The analysis also showed that a high compression force crushed the granules coated by TR-FB, which impaired sustained drug release. From the regression model the optimal manufacturing conditions were determined, and the tablet prepared under these conditions concurred with the predicted values and met all criteria. This new technique should contribute to the development of ODT to improve medication adherence.


Assuntos
Compostos de Alumínio/química , Compostos de Magnésio/química , Silicatos/química , Administração Oral , Adsorção , Ésteres/química , Ácidos Graxos/química , Glicerol/química , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Propriedades de Superfície , Comprimidos/administração & dosagem , Comprimidos/química
5.
Curr Microbiol ; 76(12): 1398-1406, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31583437

RESUMO

Conventional glycoconjugates are prepared with polysaccharides (PS) isolated from bacterial sources by fermentation technique. This approach has some major challenges like lower yield of PS, impurities and usage of hazardous chemicals. Reports on efficient and enhanced production of PS from Shigella flexneri is meager in literature. Hence, in the current study, three different types of media namely Yeast extract medium, Shigella sonnei-defined medium and synthetic medium were utilized for the culture of S. flexneri. Among the selected media it was recognized that the culture of S. flexneri harvested in synthetic media produced significant quantity of PS in less time when compared to the other two media. Different purification techniques such as phenol chloroform extraction, acid precipitation, detergent method, chromatographic purification and a novel silicate method were carried out to refine the harvested PS from impurities. It was observed that large impurities such as bacterial protein, debris and media components were eliminated significantly by using chromatographic and silicate methods. The final yield of purified PS was approximately 20-35% higher in silicate method which is reported for the first time in this study for purification of PS. Further, the characterization of the purified PS was done using high-performance liquid chromatography and high-performance anion-exchange chromatography with pulsed amperometric detection. Hence, the robust process developed in the present study using synthetic media and chromatographic filtration technique along with the novel silicate treatment produced significant quantities of PS from S. flexneri in reduced cost and time, which could be further conjugated to a suitable carrier to generate a potential Shigella conjugate antigen.


Assuntos
Microbiologia Industrial/métodos , Polissacarídeos Bacterianos/isolamento & purificação , Polissacarídeos Bacterianos/metabolismo , Shigella flexneri/metabolismo , Vacinas Bacterianas/imunologia , Cromatografia Líquida , Meios de Cultura/química , Shigella flexneri/crescimento & desenvolvimento , Silicatos/química
6.
Nat Commun ; 10(1): 4586, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594932

RESUMO

Upconversion nanoparticles (UCNPs) are the preferred choice for deep-tissue photoactivation, owing to their unique capability of converting deep tissue-penetrating near-infrared light to UV/visible light for photoactivation. Programmed photoactivation of multiple molecules is critical for controlling many biological processes. However, syntheses of such UCNPs require epitaxial growth of multiple shells on the core nanocrystals and are highly complex/time-consuming. To overcome this bottleneck, we have modularly assembled two distinct UCNPs which can individually be excited by 980/808 nm light, but not both. These orthogonal photoactivable UCNPs superballs are used for programmed photoactivation of multiple therapeutic processes for enhanced efficacy. These include sequential activation of endosomal escape through photochemical-internalization for enhanced cellular uptake, followed by photocontrolled gene knockdown of superoxide dismutase-1 to increase sensitivity to reactive oxygen species and finally, photodynamic therapy under these favorable conditions. Such programmed activation translated to significantly higher therapeutic efficacy in vitro and in vivo in comparison to conventional, non-programmed activation.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Processos Fotoquímicos/efeitos da radiação , Animais , Compostos de Cálcio/química , Linhagem Celular Tumoral , Permeabilidade da Membrana Celular , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/efeitos da radiação , Desenho de Drogas , Endossomos/efeitos dos fármacos , Técnicas de Inativação de Genes , Células HeLa , Humanos , Indóis/administração & dosagem , Indóis/farmacocinética , Raios Infravermelhos , Camundongos , Nanopartículas/efeitos da radiação , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Compostos Organometálicos/administração & dosagem , Compostos Organometálicos/farmacocinética , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/farmacocinética , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Silicatos/química , Superóxido Dismutase-1/genética , Distribuição Tecidual , Raios Ultravioleta
7.
Molecules ; 24(19)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561457

RESUMO

Porous glass was prepared by the hydrothermal reaction of sodium borosilicate glass, and oxygen-ion characterization was used to identify the hydroxyl groups in its surface area. A substantial amount of "water" was introduced into the ionic structure as either OH- groups or H2O molecules through the hydrothermal reaction. When the hydrothermally treated glass was reheated at normal pressures, a porous structure was formed due to the low-temperature foaming resulting from the evaporation of H2O molecules and softening of the glass. Although it was expected that the OH- groups would remain in the porous glass, their distribution required clarification. Oxygen K-edge X-ray absorption fine structure (XAFS) spectroscopy enables the bonding states of oxygen ions in the surface area and interior to be characterized using the electron yield (EY) and fluorescence yield (FY) mode, respectively. The presence of OH- groups was detected in the O K-edge XAFS spectrum of the porous glass prepared by hydrothermal reaction with a corresponding pre-edge peak energy of 533.1 eV. In addition, comparison of the XAFS spectra obtained in the EY and FY modes revealed that the OH- groups were mainly distributed in the surface area (depths of several tens of nanometers).


Assuntos
Vidro/química , Íons/química , Oxigênio/química , Silicatos/química , Espectroscopia por Absorção de Raios X , Porosidade , Temperatura Ambiente , Água/química
8.
Braz Oral Res ; 33: e042, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508725

RESUMO

This study evaluated the cytotoxicity and biocompatibility of a new bioceramic endodontic sealer (i.e., Sealer Plus BC) in comparison with those of MTA Fillapex and AH Plus. L929 fibroblasts were cultured and Alamar Blue was used to evaluate cell viability of diluted extracts (1:50, 1:100, and 1:200) from each sealer at 24 h. Polyethylene tubes that were filled with material or empty (as a control) were implanted in the subcutaneous tissue of rats. The rats were killed after 7 and 30 d (n = 8), and the tubes were removed for histological analysis. Parametric data was analyzed using a one-way ANOVA test, and nonparametric data was analyzed via the Kruskal-Wallis test followed by the Dunn test (p < 0.05). A reduction in cell viability was observed in the extracts that were more diluted for Sealer Plus BC when compared to that of Control and AH Plus (p < 0.05). However, the 1:50 dilution of the Sealer Plus BC was similar to that of the Control (p > 0.05). Conversely, more diluted extracts of MTA Fillapex (1:200) and AH Plus (1:100 and 1:200) were similar to the Control (p > 0.05). Histological analysis performed at 7 d did not indicate any significant difference between tissue response for all materials, and the fibrous capsule was thick (p > 0.05). At 30 d, Sealer Plus BC was similar to the Control (p > 0.05) and MTA Fillapex and AH Plus exhibited greater inflammation than the Control (p < 0.05). The fibrous capsule was thin for the Control and for most specimens of Sealer Plus BC and AH Plus. Thus, Sealer Plus BC is biocompatible when compared to MTA Fillapex and AH Plus, and it is less cytotoxic when less-diluted extracts are used.


Assuntos
Cimentos para Ossos/química , Hidróxido de Cálcio/química , Cerâmica/química , Materiais Restauradores do Canal Radicular/química , Compostos de Alumínio/química , Animais , Materiais Biocompatíveis , Cimentos para Ossos/farmacologia , Cimentos para Ossos/toxicidade , Compostos de Cálcio/química , Hidróxido de Cálcio/farmacologia , Hidróxido de Cálcio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas/efeitos dos fármacos , Combinação de Medicamentos , Resinas Epóxi/química , Fibroblastos/efeitos dos fármacos , Técnicas In Vitro , Inflamação , Masculino , Teste de Materiais , Óxidos/química , Ratos Wistar , Materiais Restauradores do Canal Radicular/toxicidade , Silicatos/química , Tela Subcutânea/patologia
9.
J Appl Oral Sci ; 27: e20180556, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31508791

RESUMO

OBJECTIVE: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. METHODOLOGY: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers' instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). RESULTS: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. CONCLUSIONS: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Dimetilpolisiloxanos/química , Resinas Epóxi/química , Guta-Percha/química , Óxidos/química , Materiais Restauradores do Canal Radicular/química , Silicatos/química , Ondas Ultrassônicas , Análise de Variância , Combinação de Medicamentos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Solubilidade , Estatísticas não Paramétricas , Propriedades de Superfície , Fatores de Tempo
10.
Mater Sci Eng C Mater Biol Appl ; 105: 110032, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546347

RESUMO

Removing malignant bone tumors results in critical size bone defects. These voids in bones should be filled by a proper scaffold that not only can support cell ingrowth and bone regeneration but also it has to show a desirable ability in long-term releasing anticancer drugs in order to prevent the growth of remaining cancer cells. Applying this scaffold can significantly improve the outcome of bone tumors treatment. In this study, a novel way is proposed for immobilization of doxorubicin (DOX)-loaded polycaproloactone (PCL) microparticles on the hardystonite (HT) scaffold surfaces. High interconnected porous HT scaffolds with immobilized DOX-encapsulated PCL microparticles can be successfully fabricated by modified water/oil/water method. In the present work, we verify a slow release of DOX over 30 days from PCL microparticles inside HT scaffold. Our developed HT scaffolds with the long-term release of DOX are more effective in reduction of Saos-2 cancer cells viability and induce higher degrees of apoptosis compared to DOX dip coated HT scaffolds. Encapsulating DOX into PCL microparticles significantly improves the anti-tumor activity of DOX by regulating the expression of apoptosis-related genes. Our results suggest that by immobilization of polymeric vehicles on the ceramic scaffold for controlled drug release, we can achieve high efficiency in apoptosis of cancer cells.


Assuntos
Osso e Ossos/fisiologia , Sistemas de Liberação de Medicamentos/métodos , Engenharia Tecidual/métodos , Apoptose/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Caspases/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Difusão Dinâmica da Luz , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Microesferas , Estresse Oxidativo/efeitos dos fármacos , Poliésteres/química , Porosidade , Silicatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tecidos Suporte/química
11.
Mater Sci Eng C Mater Biol Appl ; 105: 110009, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546356

RESUMO

In the present study, a two-step sintering (TSS) method has been used to improve the mechanical properties, biocompatibility, drug release, and osteogenesis abilities of hardystonite (HT) ceramic scaffolds for tissue engineering and drug delivery applications. The average particle size of HT scaffold is kept lower than 80 nm and is reached higher than 130 nm by using two-step and conventional sintering methods, respectively. The compressive strengths of the prepared nanocrystalline HT scaffolds were found to be significantly higher than those of the micro-structure HT and currently available hydroxyapatite scaffolds. A comparative analysis of cell viability and live/dead staining of human mesenchymal stem cells (hMSCs) in nano- and micro-structured HT scaffolds and their drug release potentiation was carried out. The results showed that the nano-structured HT scaffolds have higher cell viability, biocompatibility and longer-term doxorubicin (DOX) release potential than the micro-structured ones. The results of quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) analyses showed that the expression of adhesion and differentiation supporting genes were significantly higher in nano-structured HT scaffolds as compared to the micro-structured ones. The results of qRT-PCR also showed that the mRNA expression level of ERK1/2 and P38 MAPK from hMSCs were significantly higher in nano-structured HT scaffolds than the micro-structured ones. These results potentially open new aspects for using nano-structured scaffolds in bone tissue engineering applications.


Assuntos
Materiais Biocompatíveis/química , Cerâmica/química , Temperatura Alta , Engenharia Tecidual/métodos , Tecidos Suporte/química , Biomarcadores/metabolismo , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Força Compressiva , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Nanoestruturas/química , Osteocalcina/metabolismo , Osteonectina/metabolismo , Tamanho da Partícula , Silicatos/química , Fatores de Tempo , Difração de Raios X
12.
Mater Sci Eng C Mater Biol Appl ; 105: 110076, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31546443

RESUMO

The composite scaffolds of bioactive glasses and polymers are often used in bone regeneration which could improve the stiffness, compressive strength and bioactivity of polymers while maintaining the osteoconductivity and osteoinductivity of bioactive glasses. But due to complicated situations and limitations of compositing process, the prepared composite materials have low uniformity and obvious phase separation, leading to problems such as poor mechanical properties and inferior new bone formation capacity. In this paper, a modified sol-gel processing technique was used to realize the homogeneous inorganic-organic composites. After hydrolysis of the metal alkoxide, the sol was mixed with the aqueous solution of polyvinyl alcohol (PVA), and through gelation and chemical reaction, the mixture was solidified into the inorganic-organic composite hydrogel. The composites showed as a uniform single phase with interpenetrating networks of PVA gel and borosilicate gel (BG) that chemically and physically interacted at the scale of molecular or nanometer, therefore PVA-BG hybrids were obtained. When immersed in phosphate-buffered saline, the PVA-BG hybrid-derived scaffolds released beneficial ions into the medium and converted to hydroxyapatite. The scaffolds were not toxic to the rat bone marrow-derived mesenchymal stem cells (rBMSCs), and supported rBMSCs proliferation. Furthermore, the alkaline phosphatase activity of the rBMSCs and the expression levels of osteogenic-related genes (alkaline phosphatase, osteocalcin and runt-related transcription factor 2) increased significantly with increasing amount of BG in the hybrid scaffolds. Finally, the bone defect repair results of critical-sized femoral condyle defect rat model demonstrated that PVA-BG hybrid scaffolds could enhance bone regeneration compared with PVA scaffolds. The results suggested that PVA-BG hybrid scaffolds may be a promising biomaterial for bone regeneration.


Assuntos
Células da Medula Óssea/metabolismo , Regeneração Óssea , Células-Tronco Mesenquimais/metabolismo , Osteogênese , Álcool de Polivinil/química , Silicatos/química , Tecidos Suporte/química , Animais , Células da Medula Óssea/citologia , Células-Tronco Mesenquimais/citologia , Ratos , Ratos Sprague-Dawley
13.
Geobiology ; 17(6): 691-707, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31478592

RESUMO

On rocky planets such as Earth and Mars the serpentinization of olivine in ultramafic crust produces hydrogen that can act as a potential energy source for life. Direct evidence of fluid-rock interaction on Mars comes from iddingsite alteration veins found in martian meteorites. In the Yamato 000593 meteorite, putative biosignatures have been reported from altered olivines in the form of microtextures and associated organic material that have been compared to tubular bioalteration textures found in terrestrial sub-seafloor volcanic rocks. Here, we use a suite of correlative, high-sensitivity, in situ chemical, and morphological analyses to characterize and re-evaluate these microalteration textures in Yamato 000593, a clinopyroxenite from the shallow subsurface of Mars. We show that the altered olivine crystals have angular and micro-brecciated margins and are also highly strained due to impact-induced fracturing. The shape of the olivine microalteration textures is in no way comparable to microtunnels of inferred biological origin found in terrestrial volcanic glasses and dunites, and rather we argue that the Yamato 000593 microtextures are abiotic in origin. Vein filling iddingsite extends into the olivine microalteration textures and contains amorphous organic carbon occurring as bands and sub-spherical concentrations <300 nm across. We propose that a martian impact event produced the micro-brecciated olivine crystal margins that reacted with subsurface hydrothermal fluids to form iddingsite containing organic carbon derived from abiotic sources. These new data have implications for how we might seek potential biosignatures in ultramafic rocks and impact craters on both Mars and Earth.


Assuntos
Meio Ambiente Extraterreno/química , Compostos de Ferro/química , Compostos de Magnésio/química , Marte , Meteoroides , Silicatos/química , Exobiologia
14.
Mater Sci Eng C Mater Biol Appl ; 104: 109999, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499945

RESUMO

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/ß-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Compostos de Cálcio/química , Compostos de Cálcio/farmacologia , Quitosana/química , Gadolínio/química , Gadolínio/farmacologia , Silicatos/química , Silicatos/farmacologia , Fosfatase Alcalina/metabolismo , Animais , Materiais Biocompatíveis/química , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Masculino , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Osteogênese/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Engenharia Tecidual/métodos , Tecidos Suporte/química , Regulação para Cima/efeitos dos fármacos
15.
Mater Sci Eng C Mater Biol Appl ; 104: 109980, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500011

RESUMO

The aim of this study was to solidify a ticagrelor loaded self-microemulsifying drug delivery system (TCG-SM) with enhanced dissolution and bioavailability of ticagrelor (TCG) for developing TCG-SM granules and tablets. TCG was dissolved in the self-microemulsifying drug delivery system (SMEDDS) and TCG-SM was solidified by adsorption to the optimized adsorbent through statistical design. In order to select an appropriate adsorbent, the physical properties (bulk density, tapped density, angle of repose, and liquid adsorption capacity) of silica-based adsorbents (Neusilin US2, Florite R, Aerosil 200, and Florite PS-10) and non silica-based adsorbents (Avicel PH102, Pharmatose 100M, Pearlitol 200, LH-11, and Emcompress) were investigated. Neusilin US2 and Florite R were selected as suitable adsorbents and their mixing ratios were optimized using statistical experimental design. The predicted values of physical properties by statistical design showed the error percentage of <10% compared to actual values. As a result of the statistical approach, TCG-SM (490 mg) was successfully solidified with Nesulin US2 (167.8 mg) and Florite R (82.2 mg), which showed good powder properties and improved dissolution of TCG. The solidified TCG-SM (Sol-TCG-SM), disintegrant (croscarmellose sodium), diluent (microcrystalline cellulose), binder (polyvinylpyrrolidone), and lubricant (magnesium stearate) were mixed to prepare granules. And, the granules with total weight of 900 mg were tableted using 16 mm oval-shape punch. The prepared Sol-TCG-SM tablet showed good tablet properties and maintained self-microemulsifying ability, such as microemulsion formation and enhanced dissolution of TCG. In vivo pharmacokinetic study, the relative bioavailability of Sol-TCG-SM exhibited 108.1% and 632.7% compared to TCG-SM and raw TCG powder, respectively. In conclusion, we successfully solidified SMEDDS with improved oral bioavailability of insoluble drugs such as TCG through a statistical design. This suggests a new approach that can be utilized in the production of solidified SMEDDS.


Assuntos
Emulsões/química , Solubilidade/efeitos dos fármacos , Ticagrelor/química , Administração Oral , Compostos de Alumínio/química , Animais , Disponibilidade Biológica , Celulose/química , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Excipientes/química , Compostos de Magnésio/química , Masculino , Pós/química , Ratos , Ratos Sprague-Dawley , Silicatos/química , Dióxido de Silício/química , Comprimidos/química
16.
ACS Appl Mater Interfaces ; 11(38): 34621-34633, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31483598

RESUMO

In situ tissue repair holds great potential as a cell-free regenerative strategy. A critical aspect of this approach is the selection of cell instructive materials that can efficiently regulate the defect microenvironment via the release of chemoattractant factors to mobilize and recruit endogenous stem cells toward the site of implantation. Here we report the design of a DNA-based hydrogel as a drug delivery platform for the sustained release of a promising chemoattractant, SDF-1α. The hydrogel is composed of chemically cross-linked DNA strands, which are bridged via silicate nanodisks (nSi). Silicate nanodisks electrostatically interact with the negatively charged DNA backbone resulting in the formation of a dual cross-linked nanocomposite hydrogel with a combination of chemical and physical cross-link points. The formulated nanocomposites display enhanced elasticity and mechanical toughness as compared to their nonsilicate containing counterparts. Moreover, the electrostatic interaction between nSi and SDF-1α leads to sustained release of the chemokine from the hydrogels. The in vitro bioactivity assays confirm the retention of chemotactic properties of the protein after its release. Overall, the dual cross-linked DNA-based hydrogel platform could be potentially used as a cell-instructive material for the recruitment of host stem cells to guide the process of in situ tissue repair.


Assuntos
Movimento Celular/efeitos dos fármacos , Quimiocina CXCL12 , DNA/química , Hidrogéis/química , Nanoestruturas/química , Silicatos/química , Células-Tronco/metabolismo , Animais , Quimiocina CXCL12/química , Quimiocina CXCL12/farmacocinética , Quimiocina CXCL12/farmacologia , Humanos , Camundongos , Células RAW 264.7 , Células-Tronco/citologia
17.
Chemistry ; 25(56): 12916-12919, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31397017

RESUMO

Inorganic cells bearing calcium silicate membranes were prepared and resembled closed chemical gardens. It was demonstrated that these inorganic cells can successfully be loaded with natural products, proteins and plasmid DNA, and their cargo can be released in a controlled manner. These cells demonstrated the ability of chemical gardens to act as platforms for the sustained delivery of biomolecules and are expected to introduce chemical gardens in the field of biosciences.


Assuntos
Portadores de Fármacos/química , Animais , Compostos de Cálcio/química , Bovinos , Plasmídeos/química , Plasmídeos/metabolismo , Rutina/química , Rutina/metabolismo , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Silicatos/química
18.
Chem Commun (Camb) ; 55(71): 10563-10566, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31417990

RESUMO

Besides delivering plausible prebiotic feedstock molecules and high-energy initiators, extraterrestrial impacts could also affect the process of abiogenesis by altering the early Earth's geological environment in which primitive life was conceived. We show that iron-rich smectites formed by reprocessing of basalts due to the residual post-impact heat could catalyze the synthesis and accumulation of important prebiotic building blocks such as nucleobases, amino acids and urea.


Assuntos
Argila/química , Ferro/química , Meteoroides , Silicatos/química , Aminoácidos/química , Catálise , Evolução Química , Meio Ambiente Extraterreno/química , Origem da Vida , Ureia/química
19.
J Mater Sci Mater Med ; 30(9): 98, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31440844

RESUMO

Calcium magnesium silicate glasses could be suggested for the synthesis of scaffolds for hard tissue regeneration, as they present a high residual glassy phase, high hardness values and hydroxyapatite-forming ability. The use of trace elements in the human body, such as Cu, could improve the biological performance of such glasses, as Cu is known to play a significant role in angiogenesis. Nano-bioceramics are preferable compared to their micro-scale counterparts, because of their increased surface area, which improves both mechanical properties and apatite-forming ability due to the increased nucleation sites provided, their high diffusion rates, reduced sintering time or temperature, and high mechanical properties. The aim of the present work was the evaluation of the effect of different ratios of Ethanol/TEOS and total amount of the inserted ammonia to the particle size, morphology and bioactive, hemolytic and antibacterial behavior of nanoparticles in the quaternary system SiO2-CaO-MgO-CuO. Different ratios of Ethanol/TEOS and ammonia amount affected the size and morphology of bioactive nanopowders. The optimum materials were synthesized with the highest ethanol/TEOS ratio and ammonia amount as verified by the enhanced apatite-forming ability and antibacterial and non-hemolytic properties.


Assuntos
Amônia/farmacologia , Cálcio/química , Cobre/química , Etanol/farmacologia , Silicatos/síntese química , Apatitas/síntese química , Apatitas/química , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Cerâmica/síntese química , Cerâmica/química , Relação Dose-Resposta a Droga , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Etanol/química , Vidro/química , Humanos , Teste de Materiais , Nanocompostos/química , Silicatos/química , Silicatos/farmacologia , Dióxido de Silício/química , Propriedades de Superfície/efeitos dos fármacos
20.
Environ Sci Pollut Res Int ; 26(29): 29789-29798, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31407258

RESUMO

In this study, environment-friendly inorganic basalt fiber (BF) was used as bio-carrier for wastewater treatment. To enhance the bio-affinity, raw BF was modified by grafting the diethylamino functional groups to make the surface more hydrophilic and electro-positive. Contact angle and zeta potential of modified basalt fiber (MBF) were characterized. The capacity of MBF bio-carriers was evaluated by microorganism immobilization tests. To explain the mechanism of capacity enhancement by modification, the profiles of total interaction energy barrier between raw BF (or MBF) and bacteria (Escherichia coli, E. coli) were discussed based on the extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The results showed the contact angle of fiber decreased from 89.71° to 63.08° after modification, and zeta potential increased from - 18.53 to +10.58 mV. The microorganism immobilization tests showed that the surface modification accelerated the initial bacterial adhesion on fiber. The total interaction energy barrier between MBF and E. coli disappeared as a result of electrostatic and hydrophilic attractive forces, and enhanced the irreversible adhesion. MBF bio-carrier medium provides a promising alternative to conventional bio-carrier materials for wastewater treatment. Graphical abstract.


Assuntos
Reatores Biológicos/microbiologia , Escherichia coli/crescimento & desenvolvimento , Modelos Teóricos , Silicatos/química , Águas Residuárias/química , Purificação da Água/métodos , Aderência Bacteriana , Células Imobilizadas/química , Escherichia coli/fisiologia , Interações Hidrofóbicas e Hidrofílicas , Viabilidade Microbiana , Fibras Minerais , Esgotos/química , Eletricidade Estática , Propriedades de Superfície
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