Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.326
Filter
1.
Braz. j. biol ; 84: e257070, 2024. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1360228

ABSTRACT

Nanoparticles (NPs) are insoluble particles with a diameter of fewer than 100 nanometers. Two main methods have been utilized in orthodontic therapy to avoid microbial adherence or enamel demineralization. Certain NPs are included in orthodontic adhesives or acrylic resins (fluorohydroxyapatite, fluorapatite, hydroxyapatite, SiO2, TiO2, silver, nanofillers), and NPs (i.e., a thin layer of nitrogen-doped TiO2 on the bracket surfaces) are coated on the surfaces of orthodontic equipment. Although using NPs in orthodontics may open up modern facilities, prior research looked at antibacterial or physical characteristics for a limited period of time, ranging from one day to several weeks, and the limits of in vitro studies must be understood. The long-term effectiveness of nanotechnology-based orthodontic materials has not yet been conclusively confirmed and needs further study, as well as potential safety concerns (toxic effects) associated with NP size.


Nanopartículas (NPs) são partículas insolúveis com diâmetro inferior a 100 nanômetros. Dois métodos principais têm sido utilizados na terapia ortodôntica para evitar a aderência microbiana ou a desmineralização do esmalte: NPs são incluídas em adesivos ortodônticos ou resinas acrílicas (fluoro-hidroxiapatita, fluorapatita, hidroxiapatita, SiO2, TiO2, prata, nanopreenchimentos) e NPs são revestidas nas superfícies de equipamentos ortodônticos, ou seja, uma camada fina de TiO2 dopado com nitrogênio nas superfícies do braquete. Embora o uso de NPs em ortodontia possa tornar acessível modernos recursos, pesquisas anteriores analisaram as características antibacterianas ou físicas por um período limitado de tempo, variando de 24 horas a várias semanas, por isso devem ser compreendidos os limites dos estudos in vitro. A eficácia de longo prazo de materiais ortodônticos com base em nanotecnologia ainda não foi confirmada de forma conclusiva, o que exige mais estudos, bem como potenciais preocupações de segurança (efeitos tóxicos) associadas ao tamanho da NP.


Subject(s)
Orthodontics , Demineralization , Dental Enamel , Nanoparticles , Anti-Infective Agents
2.
Braz. j. biol ; 84: e253183, 2024. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1355858

ABSTRACT

Abstract Nanoparticles are considered viable options in the treatment of cancer. This study was conducted to investigate the effect of magnetite nanoparticles (MNPs) and magnetite folate core shell (MFCS) on leukemic and hepatocarcinoma cell cultures as well as their effect on the animal model of acute myelocytic leukemia (AML). Through current study nanoparticles were synthesized, characterized by various techniques, and their properties were studied to confirm their nanostructure. Invivo study, nanoparticles were evaluated to inspect their cytotoxic activity against SNU-182 (human hepatocellular carcinoma), K562 (human leukemia), and THLE2 (human normal epithelial liver) cells via MTT test. Apoptotic signaling proteins Bcl-2 and Caspase-3 expression were inspected through RT-PCR method. A cytotoxic effect of MNPs and MFCS was detected in previous cell cultures. Moreover, the apoptosis was identified through significant up-regulation of caspase-3, with Bcl-2 down-regulation. Invitro study, AML was induced in rats by N-methyl-N-nitrosourea followed by oral treatment with MNPS and MFCS. Biochemical indices such as aspartate and alanine amino transferases, and lactate dehydrogenase activities, uric acid, complete blood count, and Beta -2-microglubulin were assessed in serum. Immunophenotyping for CD34 and CD38 detection was performed. Liver, kidney, and bone marrow were microscopically examined. Bcl-2 promoter methylation, and mRNA levels were examined. Although, both MNPs and MFCS depict amelioration in biochemical parameters, MFCS alleviated them toward normal control. Anticancer activity of MNPs and MFCS was approved especially for AML. Whenever, administration of MFCS was more effective than MNPs. The present work is one of few studies used MFCS as anticancer agent.


Resumo Nanopartículas são consideradas opções viáveis ​​no tratamento do câncer. Este estudo foi conduzido para investigar o efeito de nanopartículas de magnetita (MNPs) e núcleo de folato de magnetita (MFCS) em culturas de células leucêmicas e de hepatocarcinoma, bem como seu efeito no modelo animal de leucemia mielocítica aguda (LMA). Através do atual estudo, nanopartículas foram sintetizadas, caracterizadas por várias técnicas, e suas propriedades foram estudadas para confirmar sua nanoestrutura. No estudo in vivo, as nanopartículas foram avaliadas para inspecionar sua atividade citotóxica contra células SNU-182 (carcinoma hepatocelular humano), K562 (leucemia humana) e THLE2 (fígado epitelial humano normal) por meio do teste MTT. A expressão das proteínas sinalizadoras apoptóticas Bcl-2 e Caspase-3 foram inspecionadas através do método RT-PCR. Um efeito citotóxico de MNPs e MFCS foi detectado em culturas de células anteriores. Além disso, a apoptose foi identificada por meio de regulação positiva significativa da Caspase-3, com regulação negativa de Bcl-2. No estudo in vitro, a AML foi induzida em ratos por N-metil-N-nitrosoureia seguida por tratamento oral com MNPS e MFCS. Índices bioquímicos como aspartato e alanina aminotransferases e atividades de lactato desidrogenase, ácido úrico, hemograma completo e Beta-2-microglubulina foram avaliados no soro. A imunofenotipagem para detecção de CD34 e CD38 foi realizada. Fígado, rim e medula óssea foram examinados microscopicamente. A metilação do promotor Bcl-2 e os níveis de mRNA foram examinados. Embora tanto os MNPs quanto os MFCS representem uma melhora nos parâmetros bioquímicos, o MFCS os aliviou em direção ao controle normal. A atividade anticâncer de MNPs e MFCS foi aprovada especialmente para AML. Sempre, a administração de MFCS foi mais eficaz do que MNPs. O presente trabalho é um dos poucos estudos que utilizou o MFCS como agente anticâncer.


Subject(s)
Animals , Rats , Magnetite Nanoparticles , Liver Neoplasms , Ferric Compounds , Folic Acid
3.
Braz. j. biol ; 83: e244675, 2023. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1339348

ABSTRACT

Abstract Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.


Resumo Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.


Subject(s)
Oils, Volatile/pharmacology , Thymus Plant , Metal Nanoparticles , Anti-Infective Agents/pharmacology , Silver , Antioxidants/pharmacology
4.
Rev. biol. trop ; 70(1)dic. 2022.
Article in English | LILACS-Express | LILACS, SaludCR | ID: biblio-1387704

ABSTRACT

Abstract Introduction: Pathogenic protozoans, like Entamoeba histolytica and Trichomonas vaginalis, represent a major health problem in tropical countries; and polymeric nanoparticles could be used to apply plant extracts against those parasites. Objective: To test Curcuma longa ethanolic extract and Berberis vulgaris methanolic extracts, and their main constituents, against two species of protozoans. Methods: We tested the extracts, as well as their main constituents, curcumin (Cur) and berberine (Ber), both non-encapsulated and encapsulated in polymeric nanoparticles (NPs), in vitro. We also determined nanoparticle characteristics by photon correlation spectroscopy and scanning electron microscopy, and hemolytic capacity by hemolysis in healthy erythrocytes. Results: C. longa consisted mainly of tannins, phenols, and flavonoids; and B. vulgaris in alkaloids. Encapsulated particles were more effective (P < 0.001); however, curcumin and berberine nanoparticles were the most effective treatments. CurNPs had IC50 values (µg/mL) of 9.48 and 4.25, against E. histolytica and T. vaginalis, respectively, and BerNPs 0.24 and 0.71. The particle size and encapsulation percentage for CurNPs and BerNPs were 66.5 and 73.4 nm, and 83.59 and 76.48 %, respectively. The NPs were spherical and significantly reduced hemolysis when compared to non-encapsulated extracts. Conclusions: NPs represent a useful and novel bioactive compound delivery system for therapy in diseases caused by protozoans.


Resumen Introducción: Los protozoos patógenos, como Entamoeba histolytica y Trichomonas vaginalis, representan un importante problema de salud en los países tropicales; y se podrían usar nanopartículas poliméricas para aplicar extractos de plantas contra esos parásitos. Objetivo: Probar los extractos etanólicos de Curcuma longa y Berberis vulgaris, y sus principales constituyentes, contra dos especies de protozoos. Métodos: Probamos los extractos, así como sus principales constituyentes, curcumina (Cur) y berberina (Ber), tanto no encapsulados como encapsulados en nanopartículas poliméricas (NPs), in vitro. También determinamos las características de las nanopartículas por espectroscopía de correlación de fotones y microscopía electrónica de barrido, y la capacidad hemolítica por hemólisis en eritrocitos sanos. Resultados: C. longa tenía principalmente: taninos, fenoles y flavonoides; y B. vulgaris, alcaloides. Las partículas encapsuladas fueron más efectivas (P < 0.001); sin embargo, las nanopartículas de curcumina y berberina fueron los tratamientos más efectivos. CurNPs tenía valores IC50 (µg/mL) de 9.48 y 4.25, contra E. histolytica y T. vaginalis, respectivamente, y BerNPs 0.24 y 0.71. El tamaño de partícula y el porcentaje de encapsulación para CurNPs y BerNPs fueron: 66.5 y 73.4 nm, y 83.59 y 76.48 %, respectivamente. Los NP son esféricos y redujeron significativamente la hemólisis en comparación con los extractos no encapsulados. Conclusiones: Las NP representan un sistema de administración de compuestos bioactivos útil y novedoso para la terapia enfermedades causadas por protozoos.


Subject(s)
Trichomonas vaginalis , Berberis vulgaris , Curcuma , Entamoeba histolytica
5.
Rev. ADM ; 79(4)jul.-ago. 2022. ilus, tab
Article in Spanish | LILACS | ID: biblio-1395261

ABSTRACT

Introducción: el biofilm dental microbiano es el precursor de diversas enfermedades orales, una de ellas la caries, ésta representa la enferme- dad oral más significativa a nivel mundial, con una incidencia de 1.76 billones de niños afectados. Las nanopartículas de plata (AgNPs) se están usando como alternativa para el control y prevención del biofilm dental, ya que poseen propiedades antimicrobianas contra bacterias relacionadas a estas enfermedades. Sin embargo, no hay estudios que evalúen este comportamiento en pacientes pediátricos. Objetivo: eva- luar la actividad antimicrobiana de las AgNPs en bacterias de aislados clínicos tomados de pacientes pediátricos. Material y métodos: se tomó muestra del biofilm dental de 22 pacientes pediátricos, el efecto micro- biológico se evaluó mediante ensayos microbiológicos estandarizados internacionalmente por triplicado, usando dos diferentes tamaños de AgNPs. Resultados: los dos tamaños de AgNPs mostraron inhibición bacteriana, sin embargo, sólo se vio una diferencia estadísticamente significativa entre el género (p < 0.05), además, en general, hubo una correlación positiva significativa en relación a la concentración de las AgNPs y la velocidad del crecimiento bacteriano (p < 0.05). Conclusión: las AgNPs se pueden considerar como una alternativa para la prevención del biofilm dental y de esta manera para el control de diferentes enfermedades orales (AU))


Introduction: dental biofilm is the precursor of oral diseases, one of them dental caries, this represents the most significant oral disease worldwide with an incidence of 1.76 billion affected children. Silver nanoparticles (AgNPs) are being used as an alternative for the control and prevention of dental biofilm since they have antimicrobial properties against bacteria related to these diseases. However, there are no studies evaluating this behavior in pediatric patients. Objective: to evaluate the antimicrobial activity of AgNPs in bacteria from clinical isolates taken from pediatric patients. Material and methods: a sample of dental biofilm was taken from 22 pediatric patients, the microbiological effect was evaluated by international standardized microbiological tests in triplicate, using two different sizes of AgNPs. Results: the two sizes of AgNPs showed bacterial inhibition, however, only a statistically significant difference was seen between gender (p < 0.05), in addition, in general, there was a significant positive correlation in relation to the concentration of AgNPs and the speed bacterial growth (p < 0.05). Conclusion: AgNPs can be considered as an alternative for the prevention of dental biofilm and thus for the control of different oral diseases (AU)


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Dental Caries/prevention & control , Dental Plaque/prevention & control , Nanoparticles/therapeutic use , Bacterial Growth , Dental Care for Children/methods , Culture Media , Dental Plaque/microbiology , Age and Sex Distribution
6.
Int. j. high dilution res ; 21: 67-84, June 20, 2022.
Article in English | LILACS, HomeoIndex | ID: biblio-1396376

ABSTRACT

Homeopathy is highly controversial. The main reason for this is its use of very highly dilute medicines (high homeopathic potencies, HHP), diluted beyond the Avogadro/Loschmidt limit. Research using Nano Tracking Analysis has demonstrated the presence of particles in HHPs. This study aims to verify the results of a previous publication that identified the ionic composition of these particles in all dilutions. We used Scanning Electron Microscopy & Energy Dispersive X-Ray Spectroscopy (SEM-EDX) to examine dilutions of a commonly used homeopathic medicine, an insoluble metal, Cuprum metallicum, for the presence of particles (NPs). The homeopathic medicines tested were specially prepared according to the European pharmacopoeia standards. We compared the homeopathic dilutions/dynamizations of copper with simple dilutions and dynamized lactose controls. We observed an ionic diversity common to all preparations including HHPs but also significant differences in the relative quantity of each ion between manufacturing lines of homeopathic copper and lactose controls. The probability that the observed differences could have occurred chance alone (especially above Avogadro limit) can be rejected at p < 0.001. The essential component of these homeopathic medicines is sodium hydrogen carbonate, modulated by some other elements and by its quantity, size and shape. Homeopathic medicines made of Cuprum metallicum do contain material with a specific ionic composition even in HHPs diluted beyond the Avogadro/Loschmidt limit. This specificity can be attributed to the manufacturing process. This material demonstrates that the step-by-step process (dynamized or not) does not match the theoretical expectations of a dilution process. The starting material and dilution/dynamization method influences the nature of these NPs. Further measurements are needed on other raw materials using the same controls (solvent and simply diluted manufacturing lines) to support these findings. The role of sodium bicarbonate must be carefully studied in the future.


Subject(s)
Dynamization , Homeopathic Pharmacotechniques , Nanoparticles , Spectrometry, X-Ray Emission , Microscopy, Electron, Scanning , Cuprum Metallicum , Sodium Bicarbonate , Copper , Lactose
7.
J. oral res. (Impresa) ; 11(1): 1-13, may. 11, 2022. ilus
Article in English | LILACS | ID: biblio-1398893

ABSTRACT

Introduction: This study aimed to prepare a new root repair material including Portland cement, bismuth oxide, and nano-hydroxyapatite and analyze its physicochemical properties and its effects on the proliferation and differentiation of human dental pulp stem cells (hDPSCs). Material and Methods: Bismuth oxide as a radiopaque component and nano-hydroxyapatite particles were added to white Portland cement at 20% and 5% weight ratio, respectively. Characterization of the prepared cement was done using conventional methods. To examine the bioactivity of this new material, atomic absorption spectroscopy (AAS) was used for the investigation of the rate of calcium ions dissolution in simulated body fluid media. The viability of hDPSCs was assessed by an MTT assay after 1, 3 and 7 days. The odontogenic potential of this substance was evaluated by measuring alkaline phosphatase activity and alizarin red S staining. Results: Based on the bioactivity results, the cement presented high bio-activity, corroborating sufficiently with the calcium release patterns. The cell viability was significantly increased in new root repair material containing hydroxyapatite nanoparticles after 3 and 7 days (p<0.05). Conclusion: Moreover, alkaline phosphatase activity increased over 7 days in all experimental groups. The new cement containing nano-hydroxyapatite particles could be a good root repair material.


Objetivo: Este estudio tuvo como objetivo preparar un nuevo material de reparación de raíces que incluye cemento Portland, óxido de bismuto y nano-hidroxiapatita y analizar sus propiedades fisicoquímicas y sus efectos sobre la proliferación y diferenciación de células madre de pulpa dental humana. Material y Métodos: El óxido de bismuto como compo-nente radiopaco y las partículas de nano-hidroxiapatita se agregaron al cemento Portland blanco en una proporción en peso del 20 % y el 5 %, respectivamente. La caracterización del cemento preparado se realizó utilizando métodos con-vencionales. Para examinar la bioactividad de este nuevo material, se utilizó la espectroscopia de absorción atómica para investigar la velocidad de disolución de los iones de calcio en medio fluido corporal simulado. La viabilidad de las células madre de pulpa dental humana se evaluó mediante un ensayo MTT después de 1, 3 y 7 días. El potencial odontogénico de esta sustancia se evaluó midiendo la actividad de la fosfatasa alcalina y la tinción con rojo de alizarina S.Resultados: Con base en los resultados de bioactividad, el cemento presentó alta bioactividad, corroborando suficientemente con los patrones de liberación de calcio. La viabilidad celular aumentó significativamente en el nuevo material de reparación de raíces que contenía nanopartículas de hidroxiapatita después de 3 y 7 días (p<0,05). Conclusión: Además, la actividad de la fosfatasa alcalina aumentó durante 7 días en todos los grupos experimentales. El nuevo cemento que contiene partículas de nanohidroxiapatita podría ser un buen material de reparación radicular.


Subject(s)
Humans , Bismuthum Oxydatum , Silicates/chemical synthesis , Durapatite/chemical synthesis , Dental Cementum/chemistry , Root Canal Filling Materials , Stem Cells , Dental Pulp , Nanoparticles
8.
Int. j. high dilution res ; 21(2): 2-3, May 6, 2022.
Article in English | LILACS, HomeoIndex | ID: biblio-1396754

ABSTRACT

Homeopathy is controversial because using highly dilute medicines (high homeopathic potencies, HHP) beyond the Avogadro/Loschmidt limit. Previous publications [1,2] using NMR relaxation revealed the involvement of nanobubbles and/or nanoparticles and/or nanometric superstructures in high potentizations. Nano Tracking Analyse (NTA) demonstrated the presence of particles in HHPs [3,4]. WithSEM-EDX [5] we observed an ionic diversity common to all preparations including HHPs and significant differences in the relative quantity of each ion between different homeopathic manufacturing lines and controls. FTIR spectroscopy [6] shows that the molecular composition is that of carbonates, primarily sodium bicarbonate.Methods:To observe the materiality of homeopathic medicines a multidisciplinary approach is necessary. In collaboration with several universities,we canobserve these medications with NMR, NTA, SEM-EDX, FTIR, pH,and EPA. Results:The essential component of all already studied homeopathic medicines is sodium hydrogen carbonate modulated by some other elements in a specific quantity, size,and shape. The probability that the observed results could have occurred just by random chance can be rejected(significantlyabove the Avogadro limit) p < 0,001.Conclusions:The homeopathic medicines do contain material with a specific ionic composition even in HHPs diluted beyond the Avogadro/Loschmidt limit. This specificity can be attributed to the manufacturing process. These results demonstrate that the step-by-step process (dynamized or not) does not match the theoretical expectations in a dilution process. The starting material and dilution/dynamization method influencethe nature of these NPs. The role of carbonates and sodium bicarbonate must be carefully studied in the future. Its aqueous solution is alkaline in nature but itis an amphoteric compound, which means that the compound has both acidic as well as alkaline character. The reaction with acids results in sodium salts and carbonic acid and the reaction with the basic solution producescarbonates and water. Specific electric fields are indeed detectable.


Subject(s)
Materia Medica , Dynamization , Nanoparticles , Microscopy, Electron, Scanning , Sodium Bicarbonate/analysis
9.
Rev. mex. ing. bioméd ; 43(1): 1216, Jan.-Apr. 2022. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1389189

ABSTRACT

ABSTRACT Tissue engineering involves anchorage-dependent cells cultured on scaffolds, with growth factors added to facilitate cell proliferation. Its use in transplants implies the risk of bacterial infection. The current contribution describes the preparation and antibacterial evaluation of a chitosan-based hydrogel physically cross-linked with poly(l-lactic-coɛ-caprolactone) (PLCL) and enriched with zinc oxide nanoparticles (ZnO NPs) and trace elements (potassium and magnesium). The material was developed as a scaffold with built-in antibacterial properties. Chitosan and PLCL are biocompatible support materials applied in medicine for the repair and regeneration of damaged tissues, objectives promoted by ZnO NPs and the aforementioned trace elements. The ZnO NPs were elaborated by chemical coprecipitation. The materials were characterized by XRD, FT-IR, and SEM. Antibacterial testing was performed with strains of Escherichia coli and Staphylococcus aureus by the Kirby-Bauer method, in accordance with the NCCLS and CLSI guidelines. It was possible to obtain a homogeneous hydrogel with adequate morphology and distribution of elements. The hydrogel with 300 mM of Mg, K, and ZnO NP's showed antibacterial inhibition halos of 13 mm for S. aureus and 19 mm for E. coli. This innovative biomaterial with trace elements holds promise for tissue engineering by considering the challenge of bacterial infection.


RESUMEN La ingeniería de tejidos involucra el uso de células cultivadas en andamios con adiciones de factores de crecimiento para facilitar la proliferación celular. Su uso en trasplantes implica riesgo de infección bacteriana. La contribución actual describe la preparación y evaluación antibacteriana de un hidrogel a base de quitosano físicamente reticulado con poli (l-láctico-co-ɛ-caprolactona) (PLCL) enriquecido con nanopartículas de óxido de zinc (NP de ZnO) y oligoelementos (potasio y magnesio). El material se desarrolló como un andamio con propiedades antibacterianas. El quitosano y el PLCL son materiales de soporte biocompatibles aplicados en medicina para la reparación y regeneración de tejidos dañados, propiedades promovidas por las NP´s de ZnO y los oligoelementos antes mencionados. Las NP de ZnO se elaboraron mediante coprecipitación química. Los materiales se caracterizaron por DRX, FT-IR y SEM. Las pruebas antibacterianas se realizaron con cepas de Escherichia coli y Staphylococcus aureus por el método de KirbyBauer de acuerdo con las guías NCCLS y CLSI. Se pudo obtener un hidrogel homogéneo con adecuada morfología y distribución de elementos. El hidrogel con 300 mM de NP ZnO y oligoelementos mostró halos de inhibición antibacteriana de 13 mm para S. aureus y 19 mm para E. coli. Este biomaterial innovador con oligoelementos es prometedor para la ingeniería de tejidos al considerar el desafío de la infección bacteriana.

10.
Eng. sanit. ambient ; 27(1): 79-89, jan.-fev. 2022. tab, graf
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1364830

ABSTRACT

RESUMO A má distribuição geográfica de águas em território nacional aliada ao seu desperdício, à poluição dos cursos d'água próximos aos centros urbanos e industriais e à eficiência inadequada de processos de tratamento convencionais faz com que o tratamento e o reúso de água sejam tópicos de crescente importância no Brasil. Um dos métodos de tratamento de água são os processos de separação por membranas, como a nanofiltração. No entanto, esses processos estão sujeitos ao fenômeno de incrustação, que provoca diminuição gradativa de sua eficiência. Sendo assim, o presente trabalho visou à avaliação de diferentes métodos de pré-tratamento de água para mitigação da formação de biofilme em membranas de nanofiltração. Os processos de adsorção em partículas de alumina e desinfecção por meio de carvão ativado impregnado com nanopartículas de prata foram aplicados em uma amostra de um corpo d'água superficial. As amostras com e sem pré-tratamento foram nanofiltradas e a propensão à incrustação de cada uma foi avaliada. As eficiências de remoção de compostos orgânicos dos adsorventes empregados separadamente e em conjunto e as análises de absorção UV/Vis, microscópio eletrônico de varredura e espectroscopia de energia dispersiva do carvão ativado impregnado com nanopartículas de prata mostraram que os materiais empregados no pré-tratamento puderam ser apropriadamente sintetizados. Foi possível também identificar os principais grupos funcionais dos biopolímeros presentes nos biofilmes formados ao longo do tempo. Por fim, pôde-se observar que a adsorção da matéria orgânica é mais eficiente para o controle da incrustação rápida, enquanto o efeito bactericida se destaca no controle a longo prazo.


ABSTRACT The poor geographical distribution of water in the national territory combined with its waste, the pollution of watercourses close to urban and industrial centers, and the inadequate efficiency of conventional treatment processes make the treatment and reuse of water topics of increasing importance in Brazil. One of the advanced water treatment methods is membrane separation processes, such as nanofiltration. However, these processes are subject to fouling phenomenon, which causes a gradual decrease in the efficiency of the process. Therefore, the present work aims to evaluate different methods of pretreatment of water to mitigate the formation of biofilm in nanofiltration membranes. The adsorption processes on alumina particles and disinfection through activated carbon impregnated with silver nanoparticles were applied to a sample of a surface water body. Samples with and without pretreatment were nanofiltered and the propensity to fouling was evaluated. The efficiency of the adsorbents, used both separately and together, in removing organic compounds and the UV/Vis, scanning electron microscope, and Energy-dispersive X-ray spectroscopy analyses of the activated carbon impregnated with silver nanoparticles showed that the materials used in the pre-treatment were properly synthesized. It was also possible to identify the main functional groups of the biopolymers present in biofilms formed over time. Finally, it was observed that the adsorption of organic matter is more efficient for the control of rapid fouling while the bactericidal effect stands out in the long-term fouling control.

11.
Rev. estomatol. Hered ; 32(1): 61-67, ene.-mar 2022. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1389063

ABSTRACT

RESUMEN El tratamiento de la dentina como paso previo al procedimiento de adhesión tiene como propósito mejorar las condiciones del sustrato mejorando la fuerza de unión entre la superficie dentaria y el material de restauración, promoviendo mayor longevidad y estabilidad de la restauración. El objetivo del estudio fue realizar una revisión de la literatura que describe las propiedades de diferentes agentes acondicionantes de la dentina. Se realizó una revisión de la literatura incluyendo trabajos publicados entre el 2014 a 2020, de bases de datos médicas como PubMeb, SciELO y ScienceDirect; en idioma inglés, español y portugués. Se seleccionaron un total de 20 artículos que cumplían los criterios de inclusión. Se ha identificado en la literatura el uso de diversos agentes pre tratamiento de la dentina, principalmente agentes químicos como el hipoclorito de sodio, clorhexidina, el ácido etilenodiaminatetraacético (EDTA), las nanopartículas metálicas y las técnicas mecánicas como la abrasión por aire con óxido de aluminio y bicarbonato de sodio.


ABSTRACT Dentin treatment as a prior step to the adhesion procedure is intended to improve the substrate condition by improving the bonding strength between the tooth surfaces and the restorative material, promoting greater longevity and stability of the restoration. The objective of the study was to carry out a review of the literature that describes the properties of different conditioning agents of dentin. A review of the literature was carried out, including works published between 2014 and 2020, from medical databases such as PubMeb, SciELO and ScienceDirect; in English, Spanish and Portuguese. A total of 20 articles that met the inclusion criteria were selected. The use of various dentin pre-treatment agents has been identified in the literature, mainly chemical agents such as sodium hypochlorite, chlorhexidine, ethylenediaminetetraacetic acid (EDTA), metallic nanoparticles and mechanical techniques such as air abrasion. with aluminum oxide and baking soda.

12.
Braz. J. Pharm. Sci. (Online) ; 58: e19660, 2022. tab, graf
Article in English | LILACS | ID: biblio-1394027

ABSTRACT

Abstract In an attempt to increase molecular stability and provide controlled release, vascular endothelial growth factor (VEGF) was encapsulated into polycaprolactone (PCL) nanoparticles. Both VEGF-free and VEGF-loaded PCL nanoparticles were formulated by w/o/w double emulsion of the dichloromethane-water system in the presence of polyvinyl alcohol (PVA) and rat serum albumin. To achieve the optimal formulation concerning particle size and monodispersity, studies were carried out with different formulation parameters, including PVA concentration, homogenization time and rate. Scanning electron microscopy and dynamic light scattering analysis showed respectively that particles had a spherical shape with a smooth surface and particle size varying between 58.68-751.9 nm. All of the formulations were negatively charged according to zeta potential analysis. In vitro release study was performed in pH 7.4 phosphate-buffered saline at 37°C and released VEGF amount was measured by enzyme-linked immunosorbent assay (ELISA) method. At the end of the 35th day, 10% of total encapsulated VEGF was released with a sustained-release profile, which fitted the Korsmeyer-Peppas kinetic model. The bioactivation of the nanoparticles was evaluated using XTT and ELISA methods. As a result, the released VEGF was biologically active and also VEGF loaded PCL nanoparticles enhanced proliferation of the human umbilical vein endothelial cells in cell culture.


Subject(s)
Vascular Endothelial Growth Factor A , Nanoparticles/classification , In Vitro Techniques/methods , Enzyme-Linked Immunosorbent Assay/methods , Microscopy, Electron, Scanning/methods , Cell Culture Techniques/methods , Human Umbilical Vein Endothelial Cells
13.
Dental press j. orthod. (Impr.) ; 27(3): e222116, 2022. tab, graf
Article in English | LILACS-Express | LILACS, BBO | ID: biblio-1384695

ABSTRACT

ABSTRACT Objective: This study aimed to investigate the antimicrobial activity and shear bond strength (SBS) of orthodontic brackets to bovine enamel using experimental composites with different concentrations of silicon dioxide-coated silver nanoparticles (Ag@SiO2 NPs). Methods: Fifty bovine incisors were divided into five groups according to the composite (n = 10): G1 - Control Group (Transbond XT Resin), G2 - Experimental composite without Ag@SiO2 NPs; G3 - Experimental composite with 0.5% of Ag@SiO2 NPs; G4 - Experimental composite with 1% of Ag@SiO2 NPs; G5 - Experimental composite with 3% of Ag@SiO2 NPs. The SBS test was performed using a universal mechanical testing machine, and the adhesive remnant index (ARI) was analyzed by optical microscopy. For the antimicrobial activity evaluation, Streptococcus mutans (S. mutans) biofilm was formed for three days in hydroxyapatite discs. Posteriorly, S. mutans colony forming units (CFU) were evaluated. For SBS analysis, Analysis of Variance was used, followed by the Tukey test, at a 5% statistical significance level. The CFU data were analyzed by Kruskal-Wallis, followed by Dunn as a post-hoc test. The ARI results were analyzed descriptively. Results: There was no statistically significant difference in SBS values between the experimental and control groups (p>0.05). A 3% incorporation of Ag@SiO2 NPs statistically reduced the SBS values (p<0.05) compared to the 1% group. The addition of 3% of Ag@SiO2 NPs to the composites significantly reduced S. mutans biofilm formation, compared to group G2 (p<0.05). Conclusion: Composites incorporating 3% of Ag@SiO2 NPs presented similar SBS values compared to the control group, and showed significant antimicrobial activity.


RESUMO Objetivo: O presente estudo objetivou investigar a atividade antimicrobiana e a resistência de união ao cisalhamento (RU) de braquetes ortodônticos colados em esmalte bovino, utilizando compósitos experimentais com diferentes concentrações de nanopartículas de prata revestidas com dióxido de silício (NPs Ag@SiO2). Material e Métodos: Cinquenta incisivos bovinos foram divididos em cinco grupos, de acordo com o compósito utilizado (n = 10): G1 - Grupo Controle (Resina Transbond XT); G2 - Compósito Experimental sem NPs Ag@SiO2; G3 - Compósito Experimental com 0,5% de NPs Ag@SiO2; G4 - Composto Experimental com 1% de NPs Ag@SiO2; e G5 - Compósito Experimental com 3% de NPs Ag@SiO2. O teste de RU foi realizado em máquina universal de ensaios mecânicos, e o índice de adesivo remanescente (IAR) foi analisado por microscopia óptica. Para a avaliação da atividade antimicrobiana, biofilme de S. mutans foi formado por três dias em discos de hidroxiapatita. Posteriormente, foram avaliadas as unidades formadoras de colônias (UFC) de S. mutans. Para a análise de RU, foi utilizada a Análise de Variância, seguida do teste de Tukey, com nível de significância estatística de 5%. Os dados de UFC foram analisados por meio do teste de Kruskal-Wallis, seguido do teste post-hoc de Dunn. Os resultados de IAR foram analisados descritivamente. Resultados: Não houve diferença estatisticamente significativa nos valores de RU entre os grupos experimentais e o grupo controle (p> 0,05). A incorporação de 3% de NPs Ag@SiO2 reduziu estatisticamente os valores de RU (p< 0,05), em comparação ao grupo com 1%. A adição de 3% de NPs Ag@SiO2 ao compósito reduziu significativamente a formação de biofilme de S. mutans, em relação ao grupo G2 (p< 0,05). Conclusão: Os compósitos com incorporação de 3% de NPs Ag@SiO2 apresentaram valores de RU semelhantes ao grupo controle e demonstraram significativa atividade antimicrobiana.

14.
Braz. j. biol ; 82: e257622, 2022. tab, graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1364492

ABSTRACT

Greeen synthesis has been introduced as an alternative to chemical synthesis due to the serious consequences. Metal nanoparticles synthesized through green approach have different pharmaceutical, medical and agricultural applications. The present study followed a green and simple route for the preparation of potentially bioactive gold nanoparticles (Au NPs). Au NPs were prepared via green synthesis approach using crude basic alkaloidal portion of the tuber of Delphinium chitralense. The green synthesized Au NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) fourier transform infrared (FTIR), and UV-Visible spectrophotometer. Morphological analysis shows that Au NPs have cubic geometry with different sizes. UV-Vis spectroscopic analysis confirmed the synthesis of Au NPs while XRD proved their pure crystalline phase. The Au NPs showed promising dose dependent inhibition of both AChE and BChE as compared to the crude as well as standard drug.


A síntese verde foi introduzida como uma alternativa à síntese química devido às graves consequências. As nanopartículas metálicas sintetizadas através da abordagem verde têm diferentes aplicações farmacêuticas, médicas e agrícolas. O presente estudo seguiu uma rota verde e simples para a preparação de nanopartículas de ouro potencialmente bioativas (Au NPs). As NPs de Au foram preparadas via abordagem de síntese verde usando a porção alcaloide básica bruta do tubérculo de Delphinium chitralense. As NPs de Au sintetizadas verdes foram caracterizadas por microscopia eletrônica de transmissão (TEM), microscopia eletrônica de varredura (MEV), difração de raios X (DRX), infravermelho com transformada de Fourier (FTIR) e espectrofotômetro UV-Visível. A análise morfológica mostra que as NPs de Au possuem geometria cúbica com tamanhos diferentes. A análise espectroscópica UV-Vis confirmou a síntese de Au NPs enquanto a XRD provou sua fase cristalina pura. O Au NPs mostrou inibição dependente da dose promissora de AChE e BChE em comparação com a droga bruta e padrão.


Subject(s)
Delphinium , Plant Tubers , Enzymes , Nanoparticles , Gold
15.
China Pharmacy ; (12): 58-63, 2022.
Article in Chinese | WPRIM | ID: wpr-907013

ABSTRACT

OBJECTIVE To prepare apigenin silk fibroin(API@SF)nanoparticles and to evaluate their safety and anti-tumor activity. METHODS API@SF nanoparticles were prepared by nanoprecipitation method ,and their morphology ,particle size ,Zeta potential,drug loading amount and in vitro release were characterized. The safety of nanoparticles was evaluated by hemolysis test and HE staining. MTT assay was adopted to evaluate inhibitory effects of API@SF nanoparticles on breast cancer 4T1 cells in mice. RESULTS The prepared API@SF nanoparticles were spherical with uniform distribution. The average particle size was 406.61 nm, the polydispersity index was 0.154,the Zeta potential was -18.4 mV,and the average drug-loading amount was 5.20%. The in vitro release results showed that the release rate of the nanoparticles was relatively fast in the release medium of pH 5.0 and relatively slow in the release medium of pH 7.4. Results of hemolysis test and HE staining showed that the nanoparticles had good biocompatibility. Results of MTT assay showed that the inhibitory effect of API@SF nanoparticles on 4T1 cells was significantly higher than that of API raw materials (P<0.05),and its mechanism may be related to increasing the level of reactive oxygen species in cells. CONCLUSIONS API@SF nanoparticles are prepared successfully ,which possess good safety and anti-tumor activity.

16.
Article in Chinese | WPRIM | ID: wpr-907001

ABSTRACT

Objective@#The antibacterial properties and bonding strength of 3M orthodontic adhesive resin modified by chlorhexidine acetate (CHA) composite mesoporous silica were investigated.@*Methods@# CHA with different mass fractions was encapsulated in mesoporous silica nanoparticles (MSNs) (denoted CHA@MSNs). Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the samples. The 3M Z350XT flow resin was divided into 4 groups: group A: 3M+CHA@MSNs (0%); group B: 3M+CHA@MSNs (3%); group C: 3M+CHA@MSNs (5%); and group D: 3M+CHA@MSNs (6.4%), with mass scores of 0%, 3%, 5%, and 6.4%, respectively. The shear strength of the modified adhesive was tested by a universal electronic material testing machine, the adhesive residue was observed by a 10 × magnifying glass, and the adhesive Remnant index (ARI) was calculated. The four groups of modified adhesives were cultured with Streptococcus mutans. The OD540 value of the bacterial solution was measured by a spectrophotometer, and the amount of plaque attachment was observed by scanning electron microscopy to evaluate the antibacterial performance of the adhesives.@*Results@#Infrared spectroscopic analysis of CHA@MSNs showed that CHA was successfully loaded onto MSNs. Under scanning electron microscopy, it could be seen that, after Cha was combined with MSNs, the structure of MSNs changed, as the boundary was fuzzy and aggregated into a layered structure. A comparison of shear strength revealed a statistically significant difference between the groups containing CHA@MSNs and the groups without CHA@MSNs (P<0.05). The value of the shear strength in group D decreased the most, while there was no statistically significant difference between group B and group C (P > 0.05). There was no statistical significance across all groups (P > 0.05), suggesting that the addition of CHA@MSNs had little effect on the bracket shedding. The OD540 value of bacterial fluid indicated that the difference among groups A, B and C was statistically significant (P < 0.05), and the antibacterial effect of group C was the best; there was no statistically significant difference between group C and group D (P > 0.05).@*Conclusions@#Therefore, adding 5% CHA@MSN antibacterial agent significantly improved the antibacterial effect and did not affect the bond strength.

17.
Article in Chinese | WPRIM | ID: wpr-904740

ABSTRACT

@#Periodontitis is a common oral disease that represents one of the main causes of tooth loss in adults. In recent years, the application of nanotechnology has provided a new drug delivery system and innovative therapy for the treatment of periodontitis and opens up new prospects for the regeneration of periodontal tissue. The nanoparticle drug delivery system is composed of degradable carrier materials and drugs. Compared with the traditional film, namely, the fragment and strip-shaped periodontal local drug delivery system, the nanoparticle drug delivery system has the characteristics of biopharmaceuticals and pharmacokinetics. Moreover, it has special advantages, including controlled release of drugs, long-term maintenance of drug concentration, biodegradability and biocompatibility, etc. Antibiotics, protein drugs, such as growth factors, and nucleic acids used for gene delivery or mRNA knockout can be absorbed or dissolved in nanoparticles. Liposomes and polymer nanoparticle delivery systems can target bacteria and specific host cells. Inorganic nanoparticles and nanocrystals have good antibacterial activity that can promote periodontal tissue regeneration and play an important role in bone regeneration and bone repair. Dendrimers have internal hydrophobic and external hydrophilic structures and are good drug carriers for periodontitis.

18.
China Pharmacy ; (12): 473-480, 2022.
Article in Chinese | WPRIM | ID: wpr-920465

ABSTRACT

OBJECTIVE To study in vitro inhibitory effects of realgar nanoparticles on breast cancer stem cells. METHODS Human breast cancer MCF- 7 parent cells were selected as subjects and cultured by serum-free culture to obtain breast cancer stem cells. Using adriamycin (1 mg/L)as positive control ,same concentration of water-processed realgar as reference ,the effects of realgar nanoparticles on the proliferation of MCF- 7 parent cells and stem cells were detected by CCK- 8 method. The effects of realgar nanoparticles on the formation of mammosphere ,the ability of differentiation ,migration and invasion ,the proportion of CD44+/CD24- subgroup in breast cancer stem cells were detected by mammosphere formation and differentiation experiment , scratch experiment ,Transwell invasion experiment and flow cytometry. Western blot assay was used to detect the expression of proteins related to epithelial mesenchymal transformation pathway (E-cadherin and vimentin ) in breast cancer stem cells. RESULTS The survival rates of MCF- 7 parent cells and stem cells (except for breast cancer stem cells in both 1 mg/mL groups )in 1,5,10,40,60,80 mg/L groups of water-processed realgar and realgar nanoparticles were significantly lower than blank control group(P<0.01). The number of mammosphere (>20 stem cells )in 1,2.5,5,10 mg/L groups of water-processed realgar and realgar nanoparticles was significantly lower than blank control group (P<0.01);the volume of mammosphere decreased and the differentiated adherent cells decreased ;the healing rate of wound ,relative invasion rate (except for water-processed realgar 1 mg/L group)and the proportion of CD 44+/CD24- subgroup were significantly lower than blank control group (P<0.01). The expressions of E-cadherin in 2.5,10 mg/L groups of water-processed realgar and realgar nanoparticles was significantly higher than blank control group ,and the expressions of vimentin was significantly lower than those in blank control group (P<0.01). The above effects of realgar nanoparticles were generally better than those of water-processed realgar with the same mass concentration (P< 0.01). CONCLUSIONS Compared with water-processed realgar with the same mass concentration ,realgar nanoparti cles can significantly inhibit the proliferation of breast cancer stem cells, the formulation and differential ability of mammo- sphere,and reduce the proportion of CD 44+/CD24- subgroup. The effect may be associated with the inhibition of migration and invasion of breast cancer stem cells by inhibiting the expression of proteins related to epithelial mesenchymal transformation pathway.

19.
International Eye Science ; (12): 373-377, 2022.
Article in Chinese | WPRIM | ID: wpr-920402

ABSTRACT

@#AIM: To investigate the synthesis method of curcumin nanoparticles grafted with deoxycholic acid and the effect of curcumin nanoparticles on human retinal pigment epithelial(hRPE)cells. <p>METHODS: The synthesis and performance analysis of Cur/Chit-DC. The relationship between FITC/Chit-DC and hRPE cells was observed under an inverted fluorescence microscope after treating hRPE cells with FITC(FITC/Chit-DC)and Cur/Chit-DC(FITC/Cur/Chit-DC)for 24h, keeping them in dark for 1, 3 and 5d respectively.<p>RESULTS: By mixing Cur and Chit-DC, the nanoparticles containing chitosan derivatives were light yellow. The drug release from the nanoparticles reached equilibrium after 96h, and the cumulative drug release amount was 31.6%. After FITC/Chit-DC was treated with hRPE cells for 1d, most of Chit-DC nanoparticles were still located near the cell membrane. After 3d, the nanoparticles gradually converged towards the nucleus and most of them were located around the nucleus. After 5d, it was observed that Chit-DC nanoparticles had entered the nucleus and were partially degraded under the action of intracellular lysosomes. The relationship between Cur/Chit-DC and cellular action is roughly the same as the relationship between Chit-DC and cellular action. <p>CONCLUSION: Cur can be continuously released from Cur/Chit-DC nanoparticle, which has long-lasting sustained-release function.

20.
China Pharmacy ; (12): 338-343, 2022.
Article in Chinese | WPRIM | ID: wpr-913093

ABSTRACT

OBJECTIVE To study the effects of self-assembled nanoparticles from Shaoy ao gancao decoction (SGD-SAN)on the in vitro release and intestinal absorption of the main components of Glycyrrhiza uralensis . METHODS Gancao single decoction (GSD),Shaoyao single decoction (SSD),mixed suspension of Shaoyao and Gancao single decoction (MSSGD)and SGD (i.e. Shaoyao-Gancao decoction )were prepared ,and SAN was characterized. HPLC method was adopted to determine the contents of 7 main components (liquiritin apioside , liquiritin, isoliquiritin apioside , isoliquiritin, liquiritigenin, glycyrrhizic acid , isoliquiritigenin)in G. uralensis . The dialysis bag method was used to investigate the effects of the formation of SGD-SAN on in vitro release of 7 main components in G. uralensis with pH 1.2 HCl solution and pH 6.8 phosphate buffered solution (PBS)as release media. Single-pass intestinal perfusion study was performed to investigate the effects of the formation of SGD-SAN on the intestinal absorption of 7 main components from G. uralensis . RESULTS SAN with particle size of 200-300 nm and polydispersity index of 0.3-0.5 was found in GSD ,MSSGD and SGD. GSD-SAN and MSSGD-SAN were in rod shape while SGD-SAN was irregularly spherical under transmission electron microscope. The results of in vitro release study showed that the formation of SGD-SAN could significantly increase in vitro release of liquiritigenin ,isoliquiritigenin and glycyrrhizic acid ,and had no effect on other components of G. uralensis in pH 1.2 HCl solution. The formation of SGD-SAN also had no effect on the release of each component from G. uralensis in pH 6.8 PBS. The results of intestinal perfusion experiments showed that the formation of SGD-SAN could significantly promote the absorption of each component from G. uralensis in the ileum. CONCLUSIONS- The formation of SGD-SAN significantly improves the in vitro release of poorly soluble components from G. uralensis and promotes the intestinal absorption of main components from G. uralensis ,which is the physical structure basis for the compatibility and synergy of Paeonia lactiflora and G. uralensis .

SELECTION OF CITATIONS
SEARCH DETAIL