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1.
Bioresour Technol ; 323: 124608, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33421833

RESUMO

Pseudomonas sp. HXF1, a strain capable of heterotrophic nitrification, aerobic denitrification (HNAD), and biomineralization was identified and employed for the simultaneous removal of ammonia nitrogen (NH4+-N) and fluoride (F-). It removed 99.2% of NH4+-N without accumulation of nitrous nitrogen (NO2--N) and nitrate nitrogen (NO3--N), while removed 87.3% of F-. Response surface methodology (RSM) was used to study the best removal conditions for NH4+-N and F-. The results of nitrogen balance experiments with NH4Cl, NaNO2, and NaNO3 as single nitrogen sources and amplification experiments of denitrification genes proved that the bacterial strains may remove NH4+-N through HNAD. The experimental results of Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer (XRD) indicated that the way of F- removal may be adsorption and co-precipitation. The results demonstrated that the strain HXF1 has great potential in the biological denitrification and F- removal of groundwater.


Assuntos
Água Subterrânea , Nitrificação , Aerobiose , Amônia , Biomineralização , Desnitrificação , Fluoretos , Processos Heterotróficos , Nitritos , Nitrogênio , Pseudomonas
2.
Chemosphere ; 262: 127567, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32755692

RESUMO

Acid mine drainage (AMD) is recognized as a challenge encountered by mining industries globally. Cyclic mineralization method, namely Fe2+ oxidation/mineralization-residual Fe3+ reduction-resultant Fe2+ oxidation/mineralization, could precipitate Fe and SO42- present in AMD into iron hydroxysulfate minerals and greatly improve the efficiency of subsequent lime neutralization, but the current Fe0-mediated reduction approach increased the mineralization cycles. This study constructed a bacteria-driven biomineralization system based on the reactions of Acidithiobacillus ferrooxidans-mediated Fe2+ oxidation and Acidiphilium multivorum-controlled Fe3+ reduction, and utilized water-dropping aeration and biofilm technology to satisfy the requirement of practical application. The resultant biofilms showed stable activity for Fe conversion: the efficiency of Fe2+-oxidation, Fe-precipitation, and Fe3+-reduction maintained at 98%, 32%, and 87%, respectively. Dissolved oxygen for Fe-oxidizing bacteria growth was continuously replenished by water-dropping aeration (4.2-7.2 mg/L), and the added organic carbon was mainly metabolized by Fe-reducing bacteria. About 89% Fe and 60% SO42- were precipitated into jarosite mineral after five biomineralization cycles. Fe was removed via forming secondary mineral precipitates, while SO42- was coprecipitated into mineral within the initial three biomineralization cycles, and then mainly precipitated with Ca2+ afterwards. Fe concentration in AMD was proven to directly correlate with subsequent lime neutralization efficiency. Biomineralization for five cycles drastically reduced the amount of required lime and neutralized sludge by 75% and 77%, respectively. The results in this study provided theoretical guidance for practical AMD treatment based on biomineralization technology.


Assuntos
Ferro/análise , Poluentes Químicos da Água/análise , Acidiphilium , Acidithiobacillus , Ácidos , Bactérias/metabolismo , Biodegradação Ambiental , Biomineralização , Compostos de Cálcio , Compostos Férricos , Ferro/metabolismo , Minerais , Mineração , Óxidos , Sulfatos , Poluentes Químicos da Água/metabolismo
3.
Water Res ; 190: 116753, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360619

RESUMO

Reusing produced water (PW) as the subsequent hydraulic fracturing fluid is currently the most economical and dominant practice in the shale oil and gas industry. However, high Ca2+ present in PW needs to be removed prior to reuse to minimize the potential for well clogging and formation damage. In this study, the microbially induced calcite precipitation (MICP), as an emerging biomineralization technique mediated by ureolytic bacteria, was employed to remove Ca2+ and toxic contaminants from hypersaline PW for the first time. Batch and continuous studies demonstrated the feasibility of MICP for Ca2+ removal from hypersaline PW under low urea and nutrient conditions. Throughout the continuous biofiltration operation with biochar as the media, high removal efficiencies of Ca2+ (~96%), organic contaminants (~100%), and heavy metals (~100% for As, Cd, Mn and Ni, 92.2% for Ba, 94.2% for Sr) were achieved when PW co-treated with synthetic domestic wastewater (SDW) under the condition of PW:SDW = 1:1 & urea 4 g/L. Metagenomic sequencing analysis showed that a stable ureolytic bacterial consortium (containing Sporosarcina and Arthrobacter at the genus level) was constructed in the continuous biofiltration system under hypersaline conditions, which may play a crucial role during the biomineralization process. Moreover, the combination of the MICP and ammonium recovery could significantly reduce the acute toxicity of PW towards Vibrio fischeri by 72%. This research provides a novel insight into the biomineralization of Ca2+ and heavy metals from hypersaline PW through the MICP technique. Considering the low cost and excellent treatment performance, the proposed process has the potential to be used for both hydraulic fracturing reuse and desalination pretreatment on a large scale.


Assuntos
Carbonato de Cálcio , Sporosarcina , Biomineralização , Precipitação Química , Ureia , Água
4.
Nat Commun ; 11(1): 5678, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33173053

RESUMO

While many organisms synthesize robust skeletal composites consisting of spatially discrete organic and mineral (ceramic) phases, the intrinsic mechanical properties of the mineral phases are poorly understood. Using the shell of the marine bivalve Atrina rigida as a model system, and through a combination of multiscale structural and mechanical characterization in conjunction with theoretical and computational modeling, we uncover the underlying mechanical roles of a ubiquitous structural motif in biogenic calcite, their nanoscopic intracrystalline defects. These nanoscopic defects not only suppress the soft yielding of pure calcite through the classical precipitation strengthening mechanism, but also enhance energy dissipation through controlled nano- and micro-fracture, where the defects' size, geometry, orientation, and distribution facilitate and guide crack initialization and propagation. These nano- and micro-scale cracks are further confined by larger scale intercrystalline organic interfaces, enabling further improved damage tolerance.


Assuntos
Biomineralização , Bivalves/metabolismo , Carbonato de Cálcio/metabolismo , Cerâmica/química , Animais , Simulação por Computador , Modelos Biológicos
5.
Braz Dent J ; 31(5): 477-484, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33146330

RESUMO

This study evaluated the biocompatibility, biomineralization, and collagen fiber maturation induced by Resorbable Tissue Replacement (RTR®; ß-tricalcium phosphate [TCP]), Bioglass (BIOG; bioactive glass), and DM Bone® (DMB; hydroxyapatite and ß-TCP) in vivo. Sixty-four polyethylene tubes with or without (control group; CG) materials (n=8/group/period) were randomly implanted in the subcutaneous tissue of 16 male Wistar rats (four per rat), weighting 250 to 280 g. The rats were killed after 7 and 30 days (n=8), and the specimens were removed for analysis of inflammation using hematoxylin-eosin; biomineralization assay using von Kossa (VK) staining and polarized light (PL); and collagen fiber maturation using picrosirius red (PSR). Nonparametric data were statistically analyzed by Kruskal-Wallis and Dunn tests, and parametric data by one-way ANOVA test (p<0.05). At 7 days, all groups induced moderate inflammation (p>0.05). At 30 days, there was mild inflammation in the BIOG and CG, and moderate inflammation in the RTR and DMB groups, with a significant difference between the CG and RTR (p<0.05). The fibrous capsule was thick at 7 days and predominantly thin at 30 days in all groups. All materials exhibited structures that stained positively for VK and PL. Immature collagen fibers were predominant at 7 and 30 days in all groups (p>0.05), although DMB exhibited more mature fibers than BIOG at 30 days (p<0.05). RTR, BIOG, and DMB were biocompatible, inducing inflammation that reduced over time and biomineralization in the subcutaneous tissue of rats. DMB exhibited more mature collagen fibers than BIOG over a longer period.


Assuntos
Biomineralização , Materiais Restauradores do Canal Radicular , Compostos de Alumínio , Animais , Materiais Biocompatíveis , Compostos de Cálcio , Cerâmica , Colágeno , Masculino , Teste de Materiais , Óxidos , Ratos , Ratos Wistar , Silicatos , Tela Subcutânea
6.
Nat Commun ; 11(1): 4530, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913195

RESUMO

Various cancer cells have been demonstrated to have the capacity to form plasmonic gold nanoparticles when chloroauric acid is introduced to their cellular microenvironment. But their biomedical applications are limited, particularly considering the millimolar concentrations and longer incubation period of ionic gold. Here, we describe a simplistic method of intracellular biomineralization to produce plasmonic gold nanoparticles at micromolar concentrations within 30 min of application utilizing polyethylene glycol as delivery vector for ionic gold. We have characterized this process for intracellular gold nanoparticle formation, which progressively accumulates proteins as the ionic gold clusters migrate to the nucleus. This nano-vectorized application of ionic gold emphasizes its potential biomedical opportunities while reducing the quantity of ionic gold and required incubation time. To demonstrate its biomedical potential, we further induce in-situ biosynthesis of gold nanoparticles within MCF7 tumor mouse xenografts which is followed by its photothermal remediation.


Assuntos
Cloretos/administração & dosagem , Portadores de Fármacos/química , Compostos de Ouro/administração & dosagem , Ouro/química , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Nanomedicina Teranóstica/métodos , Animais , Biomineralização/efeitos da radiação , Feminino , Ouro/efeitos da radiação , Humanos , Hipertermia Induzida/métodos , Íons , Células MCF-7 , Nanopartículas Metálicas/efeitos da radiação , Camundongos , Fotoquimioterapia/métodos , Polietilenoglicóis/química , Ensaios Antitumorais Modelo de Xenoenxerto
7.
J Appl Oral Sci ; 28: e20200033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785523

RESUMO

Aim To evaluate the cytotoxicity, biocompatibility and mineralization capacity of BIO-C PULPO, and MTA. Methodology L929 fibroblasts were cultured and MTT assay was used to determine the material cytotoxicity on 6, 24, and 48 h. A total of 30 male rats (Wistar) aged between 4 and 6 months, weighing between 250 and 300 g were used. Polyethylene tubes containing BIO-C PULPO, MTA, and empty tubes were implanted into dorsal connective tissue. After the experimental periods (7, 15, 30, 60, and 90 days) the tubes were histologically analyzed using hematoxylin-eosin (H&E), immunolabeling of IL-1ß and TNF-α, and von Kossa staining, or without staining for polarized light analysis. The average number of inflammatory cells was quantified; the mineralization assessment was determined by the area marked in µm2 and semiquantitative immunolabeling analyses of IL-1ß and TNF-α were performed. Then, data underwent statistical analysis with a 5% significance level. Results It was observed that BIO-C PULPO and MTA presented cytocompatibility at 6, 24, and 48 similar or higher than control for all evaluated period. On periods 7 and 15 days, BIO-C PULPO was the material with the highest number of inflammatory cells (p<0.05). On periods 30, 60, and 90 days, BIO-C PULPO and MTA presented similar inflammatory reactions (p>0.05). No statistical differences were found between Control, BIO-C PULPO, and MTA for immunolabeling of IL-1ß and TNF-α in the different periods of analysis (p<0.05). Positive von Kossa staining and birefringent structures under polarized light were observed in all analyzed periods in contact with both materials, but larger mineralization area was found with BIO-C PULPO on day 90 (p<0.05). Conclusion BIO-C PULPO was biocompatible and induced mineralization similar to MTA.


Assuntos
Biomineralização , Cimentos Dentários , Interleucina-1beta/metabolismo , Materiais Restauradores do Canal Radicular , Fator de Necrose Tumoral alfa/metabolismo , Compostos de Alumínio , Animais , Materiais Biocompatíveis , Compostos de Cálcio , Combinação de Medicamentos , Inflamação , Masculino , Óxidos , Ratos , Ratos Wistar , Silicatos , Tela Subcutânea
8.
Proc Biol Sci ; 287(1933): 20201467, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32811320

RESUMO

Hyoliths (hyolithids and orthothecids) were one of the most successful early biomineralizing lophotrochozoans and were a key component of the Cambrian evolutionary fauna. However, the morphology, skeletogenesis and anatomy of earliest members of this enigmatic clade, as well as its relationship with other lophotrochozoan phyla remain contentious. Here, we present a new orthothecid, Longxiantheca mira gen. et sp. nov. preserved as part of secondarily phosphatized small shelly fossil assemblage from the lower Cambrian Xinji Formation of North China. Longxiantheca mira retains some ancestral traits of the clade with an undifferentiated disc-shaped operculum, a simple conical conch with apical septa and a two-layered microstructure of aragonitic fibrous bundles. The operculum interior exhibits impressions of soft tissues, including muscle attachment scars, mantle epithelial cells and a central kidney-shaped platform interpreted as a support structure in association with its presumptive feeding apparatus. The muscular system in orthothecids appears to be similar to that in hyolithids, suggesting a consistent anatomical configuration among the total group of hyoliths. The new finding of shell secreting cells demonstrates a mantle regulating the mode of growth for the operculum. Investigations of shell microstructures support the placement of hyoliths as total group molluscs with an unsettled position within the phylum Mollusca.


Assuntos
Exoesqueleto , Evolução Biológica , Moluscos , Animais , Biomineralização , Calcificação Fisiológica , Carbonato de Cálcio , China , Fósseis , Gastrópodes , Fenótipo , Pele
10.
Environ Sci Technol ; 54(16): 10128-10140, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32693580

RESUMO

Microbial iron reduction is a ubiquitous biogeochemical process driven by diverse microorganisms in a variety of environments. However, it is often difficult to separate the biological from the geochemical controls on bioreduction of Fe(III) oxides. Here, we investigated the primary driving factor(s) that mediate secondary iron mineral formation over a broad range of environmental conditions using a single dissimilatory iron reducer, Orenia metallireducens strain Z6. A total of 17 distinct geochemical conditions were tested with differing pH (6.5-8.5), temperature (22-50 °C), salinity (2-20% NaCl), anions (phosphate and sulfate), electron shuttle (anthraquinone-2,6-disulfonate), and Fe(III) oxide mineralogy (ferrihydrite, lepidocrocite, goethite, hematite, and magnetite). The observed rates and extent of iron reduction differed significantly with kint between 0.186 and 1.702 mmol L-1 day-1 and Fe(II) production ranging from 6.3% to 83.7% of the initial Fe(III). Using X-ray absorption and scattering techniques (EXAFS and XRD), we identified and assessed the relationship between secondary minerals and the specific environmental conditions. It was inferred that the observed bifurcation of the mineralization pathways may be mediated by differing extents of Fe(II) sorption on the remaining Fe(III) minerals. These results expand our understanding of the controls on biomineralization during microbial iron reduction and aid the development of practical applications.


Assuntos
Compostos Férricos , Firmicutes , Biomineralização , Ferro , Minerais , Oxirredução
11.
Sci Total Environ ; 742: 140646, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32640395

RESUMO

The sulfur ions generated during the microbial treatment of sulfate wastewater could cause secondary pollution problem, however, the application of the biomineralization technique could convert sulfur ions into sulfide nanocomposites with diverse properties. This study constructed a multi-stage process for sulfate wastewater treatment and CdS nanocomposites (CdS-NCs) recovery by using biomineralization, which simultaneously achieved the removal of pollutants and recovery of functional nanocomposites. In this process, about 97% of the sulfate could be removed, and the CdS-NCs with a diameter of 16.0-20.2 nm were collected at different pHs. The results of FTIR and Raman proved that the biomacromolecules derived from microorganisms participated in the formation of CdS-NCs. The Mott-Schottky curve suggested that the CdS-NCs belonged to n-type semiconductors with the energy gap of 2.29-2.38 eV and could be applied as the photocatalyst, and up to 78.2% of 200 mg/L tetracycline was photodegraded catalytically by CdS-NCs obtained at pH 6.5. In the application of CdS-NCs as anodes of lithium-ion batteries, all the batteries assembled by CdS-NCs exhibited a very strong cycle performance of more than 500 cycles. This research not only effectively recovered nanocomposites with great application potential from sulfate wastewater but also provided a perspective for the utilization of recovered resources.


Assuntos
Compostos de Cádmio , Nanocompostos , Biomineralização , Eletroquímica , Sulfatos , Águas Residuárias
12.
Chemosphere ; 259: 127507, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650171

RESUMO

In this study, a yeast-like fungal strain (LG-8), newly isolated from spontaneous Tibet kefir in China, was identified as Geotrichum candidum on the basis of its morphological characteristics and ITS5.8S gene sequence. Interestingly, the strain was able to remove more than 99% of Pb2+ ions in water at low concentrations and a maximum of 325.68 mg lead/g of dry biomass. The results of selective passivation experiments suggested that phosphate, amide and carboxyl groups on the cell wall contributed to lead removal. Scanning electron microscopy (SEM) photomicrographs revealed that large amounts of micro/nanoparticles formed on the cell wall, and energy dispersive X-ray spectroscopy (EDX) results further indicated the presence of lead along with phosphorus and chlorine in the particles. Furthermore, the results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses revealed that the particles were composed of pyromorphite [Pb5(PO4)3Cl], a highly insoluble lead mineral. Importantly, this is the first time that the biomineralization of lead into pyromorphite has been observed as the major mechanism for lead removal by G. candidum LG-8, providing a new strategy to scavenge heavy metals from aquatic environment in an eco-friendly manner.


Assuntos
Geotrichum/isolamento & purificação , Kefir/microbiologia , Chumbo/isolamento & purificação , Leite/microbiologia , Purificação da Água/métodos , Animais , Biomineralização , Geotrichum/metabolismo , Microscopia Eletrônica de Varredura , Minerais/química , Fosfatos/química , Análise Espectral , Tibet
13.
Life Sci ; 257: 118044, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32622944

RESUMO

AIMS: High-dose glucocorticoid (GC) administration causes osteoporosis. Many previous studies from our group and other groups have shown that melatonin participates in the regulation of osteoblast proliferation and differentiation, especially low concentrations of melatonin, which enhance osteoblast osteogenesis. However, the role of melatonin in glucocorticoid-induced osteoblast differentiation remains unknown. MATERIALS AND METHODS: An examination of the expression of osteoblast differentiation markers (ALP, OCN, COLL-1), as well as alkaline phosphatase staining and alkaline phosphatase enzymatic activity assay to measure osteoblast differentiation and quantifying Alizarin red S staining to measure mineralization, were performed to determine the effects of dexamethasone (Dex) and melatonin on the differentiation of MC3T3-E1 cells. We used immunofluorescence staining to detect the expression of Runx2 in melatonin-treated MC3T3-E1 cells. The expression of mRNA was determined by qRT-PCR, and protein levels were measured by western blotting. KEY FINDINGS: In the present study, we found that 100 µM Dex significantly reduced osteoblast differentiation and mineralization in MC3T3-E1 cells and that 1 µM melatonin attenuated these inhibitory effects. We found that only inhibition of PI3K/AKT (MK2206) and BMP/Smad (LDN193189) signalling abolished melatonin-induced differentiation and mineralization. Meanwhile, MK2206 decreased the expression of P-AKT and P-Smad1/5/9 and LDN193189 decreased the expression of P-Smad1/5/9 but had no obvious effect on P-AKT expression in melatonin-treated and Dex-induced MC3T3-E1 cells. SIGNIFICANCE: These findings suggest that melatonin rescues Dex-induced inhibition of osteoblast differentiation in MC3T3-E1 cells via the PI3K/AKT and BMP/Smad signalling pathways and that PI3K/AKT signalling may be the upstream signal of BMP/Smad signalling.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Melatonina/metabolismo , Osteoblastos/metabolismo , Animais , Biomineralização/efeitos dos fármacos , Proteína Morfogenética Óssea 2/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Calcificação Fisiológica/efeitos dos fármacos , Linhagem Celular , Dexametasona/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Glucocorticoides/efeitos adversos , Glucocorticoides/farmacologia , Melatonina/farmacologia , Camundongos , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo
14.
Arch Biochem Biophys ; 691: 108482, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32710882

RESUMO

Bone biomineralization is mediated by a special class of extracellular vesicles, named matrix vesicles (MVs), released by osteogenic cells. The MV membrane is enriched in sphingomyelin (SM), cholesterol (Chol) and tissue non-specific alkaline phosphatase (TNAP) compared with the parent cells' plasma membrane. TNAP is an ATP phosphohydrolase bound to cell and MV membranes via a glycosylphosphatidylinositol (GPI) anchor. Previous studies have shown that the lipid microenvironment influences the catalytic activity of enzymes incorporated into lipid bilayers. However, there is a lack of information about how the lipid microenvironment controls the ability of MV membrane-bound enzymes to induce mineral precipitation. Herein, we used TNAP-harboring proteoliposomes made of either pure dimyristoylphosphatidylcholine (DMPC) or DMPC mixed with either Chol, SM or both of them as MV biomimetic systems to evaluate how the composition modulates the lipid microenvironment and, in turn, TNAP incorporation into the lipid bilayer by means of calorimetry. These results were correlated with the proteoliposomes' catalytic activity and ability to induce the precipitation of amorphous calcium phosphate (ACP) in vitro. DMPC:SM proteoliposomes displayed the highest efficiency of mineral propagation, apparent affinity for ATP and substrate hydrolysis efficiency, which correlated with their highest degree of membrane organization (highest ΔH), among the tested proteoliposomes. Results obtained from turbidimetry and Fourier transformed infrared (FTIR) spectroscopy showed that the tested proteoliposomes induced ACP precipitation with the order DMPC:SM>DMPC:Chol:SM≈DMPC:Chol>DMPC which correlated with the lipid organization and the presence of SM in the proteoliposome membrane. Our study arises important insights regarding the physical properties and role of lipid organization in MV-mediated mineralization.


Assuntos
Trifosfato de Adenosina/metabolismo , Fosfatase Alcalina/metabolismo , Biomineralização/fisiologia , Fosfatos de Cálcio/metabolismo , Lipossomos/metabolismo , Proteolipídeos/metabolismo , Animais , Bovinos , Colesterol/química , Dimiristoilfosfatidilcolina/química , Hidrólise , Lipossomos/química , Proteolipídeos/química , Ratos , Esfingomielinas/química
15.
Proc Natl Acad Sci U S A ; 117(25): 14102-14109, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32522867

RESUMO

The spatial-temporal relationship between cells, extracellular matrices, and mineral deposits is fundamental for an improved understanding of mineralization mechanisms in vertebrate tissues. By utilizing focused ion beam-scanning electron microscopy with serial surface imaging, normally mineralizing avian tendons have been studied with nanometer resolution in three dimensions with volumes exceeding tens of micrometers in range. These parameters are necessary to yield sufficiently fine ultrastructural details while providing a comprehensive overview of the interrelationships between the tissue structural constituents. Investigation reveals a complex lacuno-canalicular network in highly mineralized tendon regions, where ∼100 nm diameter canaliculi emanating from cell (tenocyte) lacunae surround extracellular collagen fibril bundles. Canaliculi are linked to smaller channels of ∼40 nm diameter, occupying spaces between fibrils. Close to the tendon mineralization front, calcium-rich deposits appear between the fibrils and, with time, mineral propagates along and within them. These close associations between tenocytes, tenocyte lacunae, canaliculi, small channels, collagen, and mineral suggest a concept for the mineralization process, where ions and/or mineral precursors may be transported through spaces between fibrils before they crystallize along the surface of and within the fibrils.


Assuntos
Biomineralização , Matriz Extracelular/ultraestrutura , Tendões/ultraestrutura , Tenócitos/ultraestrutura , Animais , Cálcio/metabolismo , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Imageamento Tridimensional , Extremidade Inferior/diagnóstico por imagem , Masculino , Tenócitos/metabolismo , Perus
16.
Nature ; 583(7816): 406-410, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32555457

RESUMO

Calcified eggshells protect developing embryos against environmental stress and contribute to reproductive success1. As modern crocodilians and birds lay hard-shelled eggs, this eggshell type has been inferred for non-avian dinosaurs. Known dinosaur eggshells are characterized by an innermost membrane, an overlying protein matrix containing calcite, and an outermost waxy cuticle2-7. The calcitic eggshell consists of one or more ultrastructural layers that differ markedly among the three major dinosaur clades, as do the configurations of respiratory pores. So far, only hadrosaurid, a few sauropodomorph and tetanuran eggshells have been discovered; the paucity of the fossil record and the lack of intermediate eggshell types challenge efforts to homologize eggshell structures across all dinosaurs8-18. Here we present mineralogical, organochemical and ultrastructural evidence for an originally non-biomineralized, soft-shelled nature of exceptionally preserved ornithischian Protoceratops and basal sauropodomorph Mussaurus eggs. Statistical evaluation of in situ Raman spectra obtained for a representative set of hard- and soft-shelled, fossil and extant diapsid eggshells clusters the originally organic but secondarily phosphatized Protoceratops and the organic Mussaurus eggshells with soft, non-biomineralized eggshells. Histology corroborates the organic composition of these soft-shelled dinosaur eggs, revealing a stratified arrangement resembling turtle soft eggshell. Through an ancestral-state reconstruction of composition and ultrastructure, we compare eggshells from Protoceratops and Mussaurus with those from other diapsids, revealing that the first dinosaur egg was soft-shelled. The calcified, hard-shelled dinosaur egg evolved independently at least three times throughout the Mesozoic era, explaining the bias towards eggshells of derived dinosaurs in the fossil record.


Assuntos
Dinossauros , Casca de Ovo/anatomia & histologia , Casca de Ovo/química , Fósseis , Dureza , Animais , Evolução Biológica , Biomineralização , Carbonato de Cálcio/análise , Carbonato de Cálcio/química
17.
Gene ; 757: 144852, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32599019

RESUMO

Until now, various methods have been introduced to fabricate 3D scaffolds to provide a suitable substrate for cell growth and proliferation and subsequent use in tissue engineering to repair damaged tissues. The 3D scaffolds can simulate the natural cellular microenvironment well. Herein, the decellularized leaf spinach has been used which not only have no problems associated with artificial scaffolds, but they also do not cost significantly. Decellularized scaffolds surface properties were characterized by the investigation of scaffolds surface roughness, hydrophilicity, mechanical properties, size and shape of porosities and specific surface area. In the next step, osteogenic differentiation potential of bone marrow derived mesenchymal stem cells cultured on the scaffold and culture plate (as a control) was evaluated using alizarin staining and calcium content, alkaline phosphatase activity and bone related genes expression assays. The results indicated that the surface properties and shape of scaffold pores were effective in the stem cells binding, growth and proliferation. This higher biocompatibility due to the ideal surface hydrophilicity as well as high specific surface area due to the presence of a rough grid surface ultimately increased the efficiency of stem cell's bone differentiation. Taken together, it can be concluded that the decellularized spinach leaf scaffold, due to its easy availability, low prices and high efficiency, can be considered as a promising potential candidate for use as a proper substrate for stem cell growth and differentiation in bone tissue engineering.


Assuntos
Diferenciação Celular , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteocalcina/genética , Folhas de Planta/química , Tecidos Suporte/química , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Biomineralização , Cálcio/metabolismo , Linhagem Celular , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Osteocalcina/metabolismo , Spinacia oleracea/química
18.
Wiad Lek ; 73(5): 864-867, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32386359

RESUMO

OBJECTIVE: The aim: To establish the features of the structural organization of enamel in various anatomical areas of the tooth and determine their influence on the characteristics of the course of biomineralization processes. PATIENTS AND METHODS: Materials and methods: The study of the structural features of enamel and dentin was performed on thin sections of various groups of teeth. Then morphological, histochemical and electron microscopic examination methods were used. RESULTS: Results: The study found that there are three structural and functional barriers to biomineralization of enamel, which are located in different anatomical areas of the tooth crown. Each of them has both general and specific features. Enamel biomineralization is a continuous process of exchange of calcium ions, donor of which is brushite. The stepwise process of biomineralization turns the latter into calcium octaphosphate, which then turns into hydroxyapatite. The latter, when destroyed by carbon dioxide, forms carboxyapatite. CONCLUSION: Conclusions: In the result of conducted study was established peculiarities of enamel mineralization processes in different anatomical parts of tooth.


Assuntos
Biomineralização , Dente , Esmalte Dentário , Dentina , Microscopia Eletrônica
19.
Environ Pollut ; 260: 114051, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32369896

RESUMO

Soil contamination by toxic heavy metals such as copper is a serious problem. In this study, the extracellular polymeric substance (EPS) extracted from Rahnella sp. LRP3 was found with the potential of immobilizing Cu-polluted in soil. The EPS could bond to Cu (II) through functional groups (polysaccharides, amide, proteins, and carboxyl groups), which further developed into the porous sphere with a diameter of 20 µm. Besides, EPS could induce the formation of Cu5(PO4)2(OH)4 crystal by the biomineralization process. Finally, the EPS in the culture solution reduced 89.4 mg/kg of DTPA-Cu content by 78.99% in soil for 10 d under the condition of 25 °C via biomineralization. The results demonstrated that EPS produced by Rahnella sp. LRP3 will be a promising factor in the remediation of Cu contaminated soil.


Assuntos
Biomineralização , Cobre/química , Matriz Extracelular de Substâncias Poliméricas , Rahnella/fisiologia , Solo/química , Rahnella/efeitos dos fármacos
20.
Sci Rep ; 10(1): 7581, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32371888

RESUMO

Biomineralization is the process by which living organisms acquired the capacity to accumulate minerals in tissues. Shells are the biomineralized exoskeleton of marine molluscs produced by the mantle but factors that regulate mantle shell building are still enigmatic. This study sought to identify candidate regulatory factors of molluscan shell mineralization and targeted family B G-protein coupled receptors (GPCRs) and ligands that include calcium regulatory factors in vertebrates, such as calcitonin (CALC). In molluscs, CALC receptor (CALCR) number was variable and arose through lineage and species-specific duplications. The Mediterranean mussel (Mytilus galloprovincialis) mantle transcriptome expresses six CALCR-like and two CALC-precursors encoding four putative mature peptides. Mussel CALCR-like are activated in vitro by vertebrate CALC but only receptor CALCRIIc is activated by the mussel CALCIIa peptide (EC50 = 2.6 ×10-5 M). Ex-vivo incubations of mantle edge tissue and mantle cells with CALCIIa revealed they accumulated significantly more calcium than untreated tissue and cells. Mussel CALCIIa also significantly decreased mantle acid phosphatase activity, which is associated with shell remodelling. Our data indicate the CALC-like system as candidate regulatory factors of shell mineralization. The identification of the CALC system from molluscs to vertebrates suggests it is an ancient and conserved calcium regulatory system of mineralization.


Assuntos
Biomineralização , Calcitonina/metabolismo , Sequência de Aminoácidos , Animais , Evolução Biológica , Transporte Biológico , Biomineralização/genética , Bivalves , Calcificação Fisiológica , Calcitonina/genética , Cálcio/metabolismo , Biologia Computacional/métodos , Sequência Conservada , Ativação Enzimática , Receptores da Calcitonina/genética , Receptores da Calcitonina/metabolismo , Receptores Acoplados a Proteínas-G/classificação , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo
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