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1.
J Funct Biomater ; 14(7)2023 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-37504883

RESUMO

Facial trauma, bone resection due to cancer, periodontal diseases, and bone atrophy following tooth extraction often leads to alveolar bone defects that require bone regeneration in order to restore dental function. Guided bone regeneration using synthetic biomaterials has been suggested as an alternative approach to autologous bone grafts. The efficiency of bone substitute materials seems to be influenced by their physico-chemical characteristics; however, the debate is still ongoing on what constitutes optimal biomaterial characteristics. The purpose of this study was to develop an empirical model allowing the assessment of the bone regeneration potential of new biomaterials on the basis of their physico-chemical characteristics, potentially giving directions for the design of a new generation of dental biomaterials. A quantitative data set was built composed of physico-chemical characteristics of seven commercially available intra-oral bone biomaterials and their in vivo response. This empirical model allowed the identification of the construct parameters driving optimized bone formation. The presented model provides a better understanding of the influence of driving biomaterial properties in the bone healing process and can be used as a tool to design bone biomaterials with a more controlled and custom-made composition and structure, thereby facilitating and improving the clinical translation.

2.
Astrobiology ; 22(9): 1081-1098, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35704291

RESUMO

On Earth, the circulation of Fe-rich fluids in hydrothermal environments leads to characteristic iron mineral deposits, reflecting the pH and redox chemical conditions of the hydrothermal system, and is often associated with chemotroph microorganisms capable of deriving energy from chemical gradients. On Mars, iron-rich hydrothermal sites are considered to be potentially important astrobiological targets for searching evidence of life during exploration missions, such as the Mars 2020 and the ExoMars 2022 missions. In this study, an extinct hydrothermal chimney from the Jaroso hydrothermal system (SE Spain), considered an interesting geodynamic and mineralogical terrestrial analog for Mars, was analyzed using Raman spectroscopy, X-ray diffraction, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The sample consists of a fossil vent in a Miocene shallow-marine sedimentary deposit composed of a marl substrate, an iron-rich chimney pipe, and a central space filled with backfilling deposits and vent condensates. The iron crust is particularly striking due to the combined presence of molecular and morphological indications of a microbial colonization, including mineral microstructures (e.g., stalks, filaments), iron oxyhydroxide phases (altered goethite, ferrihydrite), and organic signatures (carotenoids, organopolymers). The clear identification of pigments by resonance Raman spectroscopy and the preservation of organics in association with iron oxyhydroxides by Raman microimaging demonstrate that the iron crust was indeed colonized by microbial communities. These analyses confirm that Raman spectroscopy is a powerful tool for documenting the habitability of such historical hydrothermal environments. Finally, based on the results obtained, we propose that the ancient iron-rich hydrothermal pipes should be recognized as singular terrestrial Mars analog specimens to support the preparatory work for robotic in situ exploration missions to Mars, as well as during the subsequent interpretation of data returned by those missions.


Assuntos
Fósseis , Marte , Exobiologia , Sedimentos Geológicos/química , Ferro/análise , Microscopia Eletrônica de Varredura , Minerais/análise , Espectrometria por Raios X , Análise Espectral Raman/métodos , Difração de Raios X
3.
Biotechnol J ; 14(8): e1800624, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31161690

RESUMO

The fungal endophyte Cyanodermella asteris (C. asteris) has been recently isolated from the medicinal plant Aster tataricus (A. tataricus). This fungus produces astin C, a cyclic pentapeptide with anticancer and anti-inflammatory properties. The production of this secondary metabolite is compared in immobilized and planktonic conditions. For immobilized cultures, a stainless steel packing immersed in the culture broth is used as a support. In these conditions, the fungus exclusively grows on the packing, which provides a considerable advantage for astin C recovery and purification. C. asteris metabolism is different according to the culture conditions in terms of substrate consumption rate, cell growth, and astin C production. Immobilized-cell cultures yield a 30% increase of astin C production, associated with a 39% increase in biomass. The inoculum type as spores rather than hyphae, and a pre-inoculation washing procedure with sodium hydroxide, turns out to be beneficial both for astin C production and fungus development onto the support. Finally, the influence of culture parameters such as pH and medium composition on astin C production is evaluated. With optimized culture conditions, astin C yield is further improved reaching a five times higher final specific yield compared to the value reported with astin C extraction from A. tataricus (0.89 mg g-1 and 0.16 mg g-1 respectively).


Assuntos
Ascomicetos/metabolismo , Meios de Cultura/química , Microbiologia Industrial/métodos , Peptídeos Cíclicos/biossíntese , Ascomicetos/citologia , Ascomicetos/crescimento & desenvolvimento , Reatores Biológicos , Células Imobilizadas , Endófitos/metabolismo , Microbiologia Industrial/instrumentação , Plâncton , Aço Inoxidável
4.
Environ Sci Pollut Res Int ; 24(9): 8017-8032, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28132192

RESUMO

Over the past decades, an increasing need in renewable resources has progressively appeared. This trend concerns not only fossil fuels but also mineral resources. Wastewater and sewage sludge contain significant concentrations in phosphate and can be considered as a fertilizer source of the utmost importance. In wastewater treatment plants, the biological uptake of phosphate is performed by a specific microbiota: the phosphate-accumulating organisms. These microorganisms are recovered in sewage sludge. Here, we aimed to investigate the occurrence of phosphate accumulators in four wastewater treatment plants. A 16S metagenetic analysis identified the main bacterial phyla extracted from the aerobic treatment: α-Proteobacteria, ß-Proteobacteria, and Sphingobacteria. An enrichment stage was performed to stimulate the specific growth of phosphate-accumulating bacteria in an acetate medium. An analysis of metabolic activities of sulfur and phosphorus highlighted strong modifications related to phosphorus and much less distinguishable effects with sulfur. A solid acetate medium containing 5-Br-4-Cl-3-indolyl phosphate was used to select potential phosphate-accumulating bacteria from the enriched consortia. The positive strains have been found to belong in the genera Acinetobacter, Corynebacterium, and Pseudomonas. Finally, electron microscopy was applied to the strains and allowed to confirm the presence of polyphosphate granules. Some of these bacteria contained granules the size of which exceeded 100 nm.


Assuntos
Bactérias/metabolismo , Fosfatos/metabolismo , Esgotos/microbiologia , Poluentes Químicos da Água/metabolismo , Bactérias/genética , Bactérias/ultraestrutura , DNA Bacteriano/genética , DNA Ribossômico/genética , Microscopia Eletrônica , Eliminação de Resíduos Líquidos
5.
Environ Sci Technol ; 49(18): 11158-66, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26301775

RESUMO

Dead leaves of the Neptune grass, Posidonia oceanica (L.) Delile, in the Mediterranean coastal zone, are colonized by an abundant "detritivorous" invertebrate community that is heavily predated by fishes. This community was sampled in August 2011, November 2011, and March 2012 at two different sites in the Calvi Bay (Corsica). Ingested artificial fibers (AFs) of various sizes and colors were found in 27.6% of the digestive tracts of the nine dominant species regardless of their trophic level or taxon. No seasonal, spatial, size, or species-specific significant differences were revealed; suggesting that invertebrates ingest AFs at constant rates. Results showed that, in the gut contents of invertebrates, varying by trophic level, and across trophic levels, the overall ingestion of AFs was low (approximately 1 fiber per organism). Raman spectroscopy revealed that the ingested AFs were composed of viscose, an artificial, cellulose-based polymer. Most of these AFs also appeared to have been colored by industrial dyes. Two dyes were identified: Direct Blue 22 and Direct Red 28. The latter is known for being carcinogenic for vertebrates, potentially causing environmental problems for the P. oceanica litter community. Techniques such as Raman spectroscopy are necessary to investigate the particles composition, instead of relying on fragment size or color to identify the particles ingested by animals.


Assuntos
Alismatales/química , Celulose/química , Invertebrados/metabolismo , Plásticos/química , Poluentes Atmosféricos/análise , Animais , Celulose/ultraestrutura , França , Mucosa Gástrica/metabolismo , Análise Espectral Raman
6.
PLoS One ; 10(5): e0128362, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26020773

RESUMO

This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%-alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E2, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE2 and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects.


Assuntos
Quitosana/química , Condrócitos/metabolismo , Matriz Extracelular/química , Mediadores da Inflamação/metabolismo , Alicerces Teciduais/química , Células Cultivadas , Condrócitos/citologia , Dinoprostona/metabolismo , Feminino , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Metaloproteinase 3 da Matriz/metabolismo , Óxido Nítrico/metabolismo
7.
Photomed Laser Surg ; 31(7): 307-14, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23756100

RESUMO

OBJECTIVE: The aim of this study was to evaluate the effect on dentinal surfaces of diode lasers (810 and 980 nm) at different parameters. MATERIALS AND METHODS: Twenty-four caries-free human impacted wisdom teeth were used. The crowns were sectioned transversely in order to expose the dentin. The smear layer was removed by a 1 min application of ethylenediaminetetraacetic acid (EDTA). Each surface was divided into four quadrants irradiated at a different output power setting for each kind of laser: 0.8, 1, 1.6, and 2 W (energy densities: 2547, 3184, 5092, and 6366 J/cm(2), irradiation speed 1 mm/sec; optical fiber diameter: 200 µm; continuous and noncontact mode). Half of the samples were stained with a graphite paste. All specimens were sent for scanning electron microscopic (SEM) analysis. Pulp temperature increases in additional 20 teeth were measured by a thermocouple. RESULTS: Diode laser irradiations at 0.8 and 1 W led to occlusion or narrowing of dentin tubules without provoking fissures or cracks. The application of graphite paste increased the thermal effects in dentin. Measurements of pulp temperature showed that irradiations at 0.8 and 1 W for a period of 10 sec in continuous mode increased pulp temperature (T ≤2°C). CONCLUSIONS: Diode lasers (810 and 980 nm) used at 0.8 and 1 W for 10 sec in continuous mode were able to seal the dentin tubules. These parameters can be considered harmless for pulp vitality, and may be effective in the treatment of dentinal hypersensitivity.


Assuntos
Dentina/efeitos da radiação , Lasers Semicondutores/uso terapêutico , Adolescente , Adulto , Sensibilidade da Dentina/radioterapia , Humanos , Técnicas In Vitro
8.
Photomed Laser Surg ; 30(11): 655-62, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23075147

RESUMO

OBJECTIVE: The aims of this in vitro study were to evaluate: (1) the influence of 5% NaOCl application on Er:YAG-irradiated dentin; and (2) its effect on the quality of adaptation of the composite restoration margins. BACKGROUND DATA: Previous research has shown that Er:YAG dentin irradiation produces a thermally affected tissue layer that results in lower bond strength than that of nonirradiated dentin. The removal of this thermally-affected layer may enhance the quality of dentin bonding. MATERIALS AND METHODS: Forty-nine caries-free extracted human molars were transversely sectioned in order to totally expose the dentin. Four standardized cavities were created on the dentinal surface of each molar. First, two cavities were irradiated with Er:YAG laser (2.94 nm): 150 mJ, 10 Hz, variable square pulse (VSP) mode (100 µsec), beam diameter=0.9 mm, speed of irradiation=1 mm/sec, 20% air and 20% water. Then, one of irradiated cavities and one of nonirradiated cavities were treated for 30 sec with 5% NaOCl solution. Finally, they went through a standard bonding treatment for composite restoration, etching, bonding, and composite filling. We obtained four groups of cavities: (1) one control group of nonirradiated cavities not pretreated with NaOCl; (2) one group of nonirradiated cavities, pretreated with NaOCl; (3) one group of irradiated cavities, not pretreated with NaOCl; and (4) one group of irradiated cavities, pretreated with NaOCl. All samples were subjected to thermocycling. Every cavity was immersed into a 0.5% solution of methylene blue. The percentage of dye penetration (microleakage) in the composite-dentin interface was evaluated. Six molars were analyzed by scanning electron microscope. RESULTS: Dye infiltration depth was significantly reduced in irradiated cavities treated with 5% NaOCl solution. CONCLUSIONS: The application of a 5% NaOCl solution on Er:YAG irradiated cavities can significantly improve the marginal quality of composite bonding.


Assuntos
Resinas Compostas/uso terapêutico , Adesivos Dentinários/farmacologia , Dentina/efeitos da radiação , Lasers de Estado Sólido , Hipoclorito de Sódio/farmacologia , Adaptação Fisiológica , Colagem Dentária/métodos , Dentina/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Dente Molar/efeitos da radiação
9.
Nat Genet ; 41(9): 1027-31, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19668215

RESUMO

The primary cilium is an antenna-like structure that protrudes from the cell surface of quiescent/differentiated cells and participates in extracellular signal processing. Here, we report that mice deficient for the lipid 5-phosphatase Inpp5e develop a multiorgan disorder associated with structural defects of the primary cilium. In ciliated mouse embryonic fibroblasts, Inpp5e is concentrated in the axoneme of the primary cilium. Inpp5e inactivation did not impair ciliary assembly but altered the stability of pre-established cilia after serum addition. Blocking phosphoinositide 3-kinase (PI3K) activity or ciliary platelet-derived growth factor receptor alpha (PDGFRalpha) restored ciliary stability. In human INPP5E, we identified a mutation affecting INPP5E ciliary localization and cilium stability in a family with MORM syndrome, a condition related to Bardet-Biedl syndrome. Together, our results show that INPP5E plays an essential role in the primary cilium by controlling ciliary growth factor and PI3K signaling and stability, and highlight the consequences of INPP5E dysfunction.


Assuntos
Cílios/metabolismo , Cílios/patologia , Mutação , Monoéster Fosfórico Hidrolases/genética , Transdução de Sinais/fisiologia , Animais , Síndrome de Bardet-Biedl/genética , Linhagem Celular , Núcleo Celular/metabolismo , Células Cultivadas , Cromonas/farmacologia , Cílios/genética , Cílios/ultraestrutura , Meios de Cultura Livres de Soro , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Inibidores Enzimáticos/farmacologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Técnica Direta de Fluorescência para Anticorpo , Corantes Fluorescentes/metabolismo , Ligação Genética , Marcadores Genéticos , Proteínas de Fluorescência Verde/metabolismo , Humanos , Indóis/metabolismo , Deficiência Intelectual/genética , Masculino , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Repetições de Microssatélites , Morfolinas/farmacologia , Obesidade/genética , Pênis/anormalidades , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Epitélio Pigmentado Ocular/citologia , Epitélio Pigmentado Ocular/metabolismo , Polimorfismo de Nucleotídeo Único , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Degeneração Retiniana/genética , Transfecção , Tubulina (Proteína)/metabolismo
10.
Tissue Cell ; 37(2): 153-65, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15748742

RESUMO

The structure of the epithelia of the branchial chamber organs (gills, branchiostegites, epipodites) and the localization of the Na(+),K(+)-ATPase were investigated in two caridean shrimps, the epibenthic Palaemon adspersus and the deep-sea hydrothermal Rimicaris exoculata. The general organization of the phyllobranchiate gills, branchiostegites and epipodites is similar in P. adspersus and in R. exoculata. The gill filaments are formed by a single axial epithelium made of H-shaped cells with thin lateral expansions and a basal lamina limiting hemolymph lacunae. In P. adspersus, numerous ionocytes are present in the epipodites and in the inner-side of the branchiostegites; immunofluorescence reveals their high content in Na(+),K(+)-ATPase. In R. exoculata, typical ionocytes displaying a strong Na(+),K(+)-ATPase specific fluorescence are observed in the epipodites only. While the epipodites and the branchiostegites appear as the main site of osmoregulation in P. adspersus, only the epipodites might be involved in ion exchanges in R. exoculata. In both species, the gill filaments are mainly devoted to respiration.


Assuntos
Decápodes/anatomia & histologia , Brânquias/enzimologia , Palaemonidae/anatomia & histologia , Água do Mar/química , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Técnica Indireta de Fluorescência para Anticorpo , Brânquias/citologia , Brânquias/ultraestrutura , Imuno-Histoquímica , Biologia Marinha , Concentração Osmolar , ATPase Trocadora de Sódio-Potássio/ultraestrutura , Temperatura
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