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1.
Braz. j. biol ; 83: e244675, 2023. tab, graf
Article in English | MEDLINE, 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
2.
Braz. j. biol ; 82: e242301, 2022. tab, graf
Article in English | MEDLINE, LILACS, VETINDEX | ID: biblio-1285599

ABSTRACT

Abstract Green synthesis of ‏silver nanoparticles (AgNPs) is an ecofriendly, cost-effective and promising approach for discovery of novel therapeutics. The aim of the current work was to biogenic synthesize, characterize AgNPs using seed extracts of three economically important varieties of date palm (Iklas, Irziz and Shishi), and assess their anti-pathogenic bacterial activities. AgNPs were synthesised then characterised using electron microscopy and Fourier transform infrared analyses. The bactericidal activities of AgNPs against five different bacterial pathogens, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae, were determined in vitro. In particular, changes in membrane integrity of virulent bacterial strains in response to AgNPs were investigated. Results of lactate dehydrogenase, alkaline phosphatase activity assays, and measurement of membrane potential revealed that the cytotoxic effects of the AgNPs were mainly centred on the plasma membrane of bacterial cells, leading to loss of its integrity and eventually cell death. In conclusion, green synthesis of AgNPs is an efficient, cost-effective and promising strategy to combat virulent antibiotic-resistant strains.


Resumo A síntese verde de nanopartículas de prata (AgNPs) é uma abordagem ecologicamente correta, econômica e promissora para a descoberta de novas terapêuticas. O objetivo do presente trabalho foi sintetizar biogênica, caracterizar AgNPs usando extratos de sementes de três variedades economicamente importantes de tamareira (Iklas, Irziz e Shishi) e avaliar suas atividades bacterianas antipatogênicas. AgNPs foram sintetizados e caracterizados usando microscopia eletrônica e análise de infravermelho por transformada de Fourier. As atividades bactericidas de AgNPs contra cinco diferentes patógenos bacterianos, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus aureus resistente à meticilina e Streptococcus pneumoniae, foram determinadas in vitro. Em particular, foram investigadas alterações na integridade da membrana de cepas bacterianas virulentas em resposta a AgNPs. Os resultados da lactato desidrogenase, dos ensaios da atividade da fosfatase alcalina e da medição do potencial de membrana revelaram que os efeitos citotóxicos dos AgNPs estavam principalmente centrados na membrana plasmática das células bacterianas, levando à perda de sua integridade e, eventualmente, à morte celular. A síntese verde de AgNPs é uma estratégia eficiente, econômica e promissora para combater cepas virulentas resistentes a antibióticos.


Subject(s)
Metal Nanoparticles , Methicillin-Resistant Staphylococcus aureus , Phoeniceae , Silver , Plant Extracts/pharmacology , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology
3.
Braz. J. Pharm. Sci. (Online) ; 58: e18594, 2022. graf
Article in English | LILACS | ID: biblio-1364422

ABSTRACT

Abstract Traditionally dates is consumed as a rich source of iron supplement and the current research discuss the synthesis of silver nanoparticles (AgNPs) using methanolic seed extract of Rothan date and its application over in vitro anti-arthritic, anti-inflammatory and antiproliferative activity against lung cancer cell line (A549). FTIR result of synthesised AgNPs reveals the presence of functional group OH as capping agent. XRD pattern confirms the crystalline nature of the AgNPs with peaks at 38º, 44º, 64º and 81º, indexed by (111), (200), (220) and (222) in the 2θ range of 10-90, indicating the face centered cubic (fcc) structure of metallic Ag. HR- TEM results confirm the morphology of AgNPs as almost spherical with high surface areas and average size of 42 ± 9nm. EDX spectra confirmed that Ag is only the major element present and the Dynamic light scattering (DLS) assisted that the Z-average size was 203nm and 1.0 of PdI value. Zeta potential showed − 26.5mv with a single peak. The results of the biological activities of AgNPs exhibited dose dependent activity with 68.44% for arthritic, antiinflammatory with 63.32% inhibition and anti-proliferative activity illustrated IC50 value of 59.66 µg/mL expressing the potential of AgNPs to combat cancer


Subject(s)
Silver , In Vitro Techniques/methods , Chronology as Topic , Nanoparticles , Phoeniceae/adverse effects , Lung Neoplasms/classification , Seeds , zeta Potential , Spectroscopy, Fourier Transform Infrared , Inhibitory Concentration 50 , Dosage/methods
4.
Braz. j. biol ; 82: e232434, 2022. tab, graf
Article in English | LILACS | ID: biblio-1153465

ABSTRACT

Abstract Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in "De Man, Rogasa, and Sharp" broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell- free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.


Resumo Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo "De Man, Rogasa e Sharp" para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.


Subject(s)
Lactobacillus delbrueckii , Metal Nanoparticles , Anti-Infective Agents , Silver/pharmacology , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology
5.
São Paulo; s.n; 20210523. 71 p.
Thesis in Portuguese | LILACS, BBO | ID: biblio-1369729

ABSTRACT

As doenças peri-implantares apresentam-se como o novo desafio da Implantodontia. Devido sua alta prevalência e grandes dificuldades no tratamento, estudos sobre alternativas preventivas poderiam trazer grande contribuição. Desta forma estudamos a aplicação de um filme antimicrobiano contendo prata em componentes protéticos dos implantes dentários. Para encontrar um equilíbrio entre efeito antimicrobiano e toxicidade, propusemos a avaliação da citotoxidade deste filme com diferentes concentrações do agente antimicrobiano, aplicados a discos de titânio, diante de cultura primária de fibroblastos. Portanto, no presente estudo investigamos a citotoxicidade de filmes nanoestruturados em discos de titânio diante de cultura primária de fibroblastos, visando desenvolver um material antimicrobiano e biocompatível capaz de impedir a colonização bacteriana em áreas reabilitadas por implantes. As culturas foram divididas nos seguintes grupos: Grupo A (controle): discos de titânio sem deposição de prata; Grupo B (teste): discos de titânio com uma camada de deposição de solução coloidal de prata e sílica, Grupo C (teste): discos de titânio com o dobro de deposição de solução coloidal de prata em relação ao grupo B, e Grupo D (teste): discos de titânio extra polidos com deposição de uma camada de solução coloidal de prata. Para a análise de citotoxicidade, os materiais foram cultivados com fibroblastos e analisados através de ensaios de citotoxicidade direta (MTT) com período de 24h, 48h e 72h de incubação buscando determinar a taxa de proliferação e viabilidade celular. Para o controle estrutural foi realizada microscopia eletrônica de varredura (MEV) após 24h de incubação. As amostras não se apresentaram como citotóxicas e novos estudos deverão ser realizados visando resultados in vivo para uma possível aplicação do revestimento em componentes protéticos de implantes.


Subject(s)
Silver , Fibroblasts
6.
Rev. méd. Urug ; 37(1): e37107, mar. 2021. tab, graf
Article in Spanish | LILACS, BNUY | ID: biblio-1289844

ABSTRACT

Resumen: Una proporción importante de infecciones en el pie diabético consisten en onicomicosis y tinea pedis, problema común en el pie, amenazante de la viabilidad del tejido que puede provocar infecciones bacterianas secundarias. Requieren períodos prolongados de tratamiento antimicótico con alta tasas de recaídas y reinfección. Diversos estudios han mostrado la seguridad y eficacia de las nanopartículas de plata (NP Ag) como agente antimicrobiano. Realizamos un estudio donde se evaluó el tratamiento con NP Ag en dermatomicosis del pie de pacientes diabéticos. Método: estudio piloto, abierto, prospectivo, randomizado y controlado en pacientes que asisten a una policlínica de pie diabético. Dieciocho pacientes cumplieron con los criterios de inclusión conformándose dos grupos homogéneos. Ambos grupos recibieron tratamiento estándar que consistió en antimicótico tópico y desbastado mecánico. El grupo intervención utilizó un textil (medias) confeccionadas con hilos con NP Ag. Se realizó control clínico y microbiológico hasta las 12 semanas. Se evaluó el porcentaje de remisión y el tiempo hasta alcanzar el mismo. Resultados: predominó la onicomicosis y el germen Trichophyton rubrum. En el grupo intervención se logró un mayor porcentaje de remisión de lesiones y en un tiempo menor que el grupo control. Conclusiones: el uso de medias confeccionadas con hilos de NP Ag se asoció con una mayor probabilidad de curación completa en un período de 12 semanas a pesar de que el número de pacientes no permitió llegar al nivel de significación estadística, pudiendo contribuir a la prevención de infecciones o úlceras suplementarias en el pie diabético.


Summary: Onychomycosis and tinea pedis represent a significant proportion of infections in the diabetic foot, a common foot problem, and they constitute a threat to the viability of tissues that may provoke secondary bacterial infections. To combat them, antifungal treatments are required for long periods of time, the rates of relapse and reinfection being high. Several studies have proved the safety and effectiveness of silver nano particles (NP Ag) as an antimicrobial agent. A study was conducted to assess nanoparticle agents for foot dermatomycosis in diabetic patients. Method: pilot, open, prospective randomized and controlled study in patients who are assisted in a diabetic foot policlinic. 18 patients complied with the inclusion criteria and two homogeneous groups were formed. Both groups received standard treatment consisting in topic antifungal and mechanical roughing. The intervention groups used a textile (stockings) made with silver nanoparticle threads. Clinical and microbiological control was made during 12 weeks, also assessing the remission percentage and the time it took to achieve it. Resultados: onychomycosis and trichophyton rubrum prevailed. The intervention group showed a greater percentage of remission of lesions in a period of time that was shorter than that of the control group. Conclusions: the use of stockings made with NP Ag threads was associated with a greater probability of complete healing, in a 12-week period, despite the fact that the number of patients was not statistically significant. This could contribute to the prevention of supplementary infections or ulcers in the diabetic foot.


Resumo: Uma proporção significativa de infecções do pé diabético consiste em onicomicose e Tinea pedis, um problema comum nos pés que ameaça a viabilidade do tecido e pode causar infecções bacterianas secundárias. Requerem períodos prolongados de tratamento antifúngico com altas taxas de recidiva e reinfecção. Vários estudos têm demonstrado a segurança e a eficácia das nanopartículas de prata (NP Ag) como agente antimicrobiano. Realizamos um estudo onde o tratamento com NP Ag foi avaliado na dermatomicose do pé de pacientes diabéticos. Método: estudo piloto, aberto, prospectivo, randomizado e controlado em pacientes atendidos em uma policlínica de pé diabético. Dezoito pacientes preencheram os critérios de inclusão, formando dois grupos homogêneos. Ambos os grupos receberam tratamento padrão que consiste em antifúngico tópico e moagem mecânica. O grupo intervenção utilizou um tecido (meias) confeccionado com fios NP Ag. O controle clínico e microbiológico foi realizado até 12 semanas. A porcentagem de remissão e o tempo para alcançá-la foram avaliados. Resultados: predominaram a onicomicose e o germe Trichophyton rubrum. No grupo intervenção, obteve-se maior percentual de remissão das lesões e em menor tempo que o grupo controle. Conclusões: o uso de meias confeccionadas com fios NP Ag esteve associado a uma maior probabilidade de cura completa, no período de 12 semanas, apesar do número de pacientes não permitir atingir o nível de significância estatística, podendo contribuir para a prevenção de infecções ou úlceras adicionais no pé diabético.


Subject(s)
Silver/therapeutic use , Onychomycosis/therapy , Diabetic Foot , Metal Nanoparticles/therapeutic use
7.
Rev. latinoam. enferm. (Online) ; 29: e3416, 2021. tab, graf
Article in English | LILACS, BDENF | ID: biblio-1289771

ABSTRACT

Objective: to analyze evidence concerning the feasibility of antimicrobial-impregnated fabrics in preventing and controlling microbial transmission in health services. Method: an integrative review using the following databases: MEDLINE (via PubMed), Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Latin American and Caribbean Health Sciences Literature (LILACS), regardless of language and date of publication. Seven studies were included in the analysis to verify the types of fabrics and substances used to impregnate the fabrics, applicability in health services, and decrease in microbial load. Results: silver nanoparticles and copper oxide are the main antimicrobial substances used to impregnate the fabrics. The patients' use of these fabrics, such as in bed and bath linens and clothing, was more effective in reducing antimicrobial load than in health workers' uniforms. Conclusion: the use of these antimicrobial-impregnated textiles, especially by patients, is a viable alternative to prevent and control microbial transmission in health services. Implementing these fabrics in health workers' uniforms requires further studies, however, to verify its effectiveness in decreasing microbial load in clinical practice.


Objetivo: analisar as evidências existentes sobre a viabilidade de utilizar têxteis impregnados com substâncias antimicrobianas na prevenção e no controle da transmissão microbiana em serviços de saúde. Método: revisão integrativa, utilizando as bases de dados MEDLINE (via PubMed), Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus e Literatura Latino-Americana em Ciências da Saúde (LILACS), sem restrição de idioma e período de publicação. Após a busca na literatura científica, foram selecionados sete estudos para análise quanto ao tipo de têxtil e substância utilizada para a impregnação, a aplicabilidade no serviço de saúde e a redução da carga microbiana. Resultados: nanopartículas de prata e óxido de cobre foram as principais substâncias antimicrobianas utilizadas para a impregnação de têxteis. A utilização desses têxteis pelos pacientes, como roupas de hotelaria e vestuário, mostrou maior eficácia na redução da carga microbiana em comparação ao uso como uniforme por profissionais de saúde. Conclusão: a utilização de têxteis impregnados com substâncias antimicrobianas, sobretudo pelos pacientes, pode ser considerada uma alternativa viável na prevenção e no controle da transmissão microbiana nos serviços de saúde. Todavia, a implementação destes têxteis, como uniforme para profissionais de saúde, ainda necessita de maiores investigações quanto à redução da carga microbiana na prática clínica.


Objetivo: analizar las evidencias existentes sobre la viabilidad de utilizar textiles impregnados con sustancias antimicrobianas en la prevención y control de la transmisión microbiana en servicios sanitarios. Método: revisión integradora, utilizando las bases de dados MEDLINE (vía PubMed), Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus y Literatura Latino-Americana em Ciências da Saúde (LILACS), sin restricción de idioma y período de publicación. Después de la búsqueda en la literatura científica, fueron seleccionados siete estudios para análisis en cuanto al tipo de textil y sustancia utilizada para impregnación, aplicabilidad en el servicio sanitario y reducción de la carga microbiana. Resultados: nanopartículas de plata y óxido de cobre fueron las principales sustancias antimicrobianas utilizadas para la impregnación de textiles. La utilización de esos textiles por los pacientes, como ropa de hotel y ropa, demostró mayor eficacia en la reducción de la carga microbiana en comparación al uso como uniforme por profesionales sanitarios. Conclusión: la utilización de textiles impregnados con sustancias antimicrobianas, sobre todo por los pacientes, puede ser considerada una alternativa viable en la prevención y control de la transmisión microbiana en los servicios sanitarios. Sin embargo, la implementación de estos textiles como uniforme para profesionales de la salud todavía necesita de mayores investigaciones en cuanto a la reducción de la carga microbiana en la práctica clínica.


Subject(s)
Humans , Protective Clothing , Silver , Textiles , Caribbean Region , Containment of Biohazards , Metal Nanoparticles , Health Services , Anti-Infective Agents
8.
Braz. dent. j ; 31(5): 485-492, Sept.-Oct. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132341

ABSTRACT

Abstract Green chemistry has been applied in different areas due to the growing demands for renewable processes and one of them is nanotechnology. The aim of this study was to characterize a formulation containing silver nanoparticles (AgNPs) produced by a green synthesis and to evaluate its antimicrobial activity. The formulation will be used as an intracanal dressing exploiting the AgNPs' antimicrobial properties, which are crucial to prevent infections and bacterial reinfections that can compromise endodontic treatments. In the green synthesis, silver nitrate was employed as the precursor salt, maltose as a reducing agent, and gelatin as a stabilizing agent. The formulation was prepared mixing 50 % of a liquid containing the AgNPs and 50 % of hydroxyethylcellulose gel at 1.5 % with proper evaluation of the process inherent parameters. Techniques such as molecular absorption spectrometry and dynamic light scattering were used in characterization step. The antimicrobial activity of the AgNPs against Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 25175 was verified according to National Comittee for Clinical Laboratory Standards (NCCLS) by determining minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). The obtained results indicated the formulation containing AgNPs produced by a green synthesis was properly characterized by the selected techniques. Furthermore, the formulation assessment proved that it is suitable for the proposal as well as it has potential to be used as an intracanal dressing since presented antimicrobial activity against all bacterial strains evaluated.


Resumo A química verde tem sido aplicada em diferentes áreas devido à crescente demanda por processos renováveis e uma delas é a nanotecnologia. O objetivo deste estudo foi caracterizar uma formulação contendo nanopartículas de prata (AgNPs) produzidas por meio de síntese verde e avaliar sua atividade antimicrobiana. A formulação será usada como curativo intracanal explorando as propriedades antimicrobianas das AgNPs que são cruciais para prevenir infecções e reinfecções bacterianas que podem comprometer os tratamentos endodônticos. Na síntese verde, nitrato de prata foi empregado como sal precursor, maltose como agente redutor e gelatina como agente estabilizador. A formulação foi preparada misturando-se 50% do líquido contendo as AgNPs e 50% de gel de hidroxietilcelulose a 1,5% com avaliação adequada dos parâmetros inerentes ao processo. Técnicas como espectrometria de absorção molecular e espalhamento dinâmico de luz foram usadas na etapa de caracterização. A atividade antimicrobiana das AgNPs contra Escherichia coli ATCC 25922, Enterococcus faecalis NCTC 775, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 e Streptococcus mutans ATCC 25175 foi verificada de acordo com o National Comittee for Clinical Laboratory Standards (NCCLS), determinando-se a concentração inibitória mínima (MIC) e a concentração bactericida mínima (MBC). Os resultados obtidos indicaram que a formulação contendo AgNPs produzidas por meio de síntese verde foi devidamente caracterizada pelas técnicas selecionadas. Além disso, a avaliação da formulação provou que ela é adequada para a proposta, bem como tem potencial para ser utilizada como curativo intracanal já que apresentou atividade antimicrobiana contra todas as cepas bacterianas avaliadas.


Subject(s)
Metal Nanoparticles , Anti-Infective Agents/pharmacology , Silver/pharmacology , Bandages , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology
9.
Braz. dent. j ; 31(4): 409-416, July-Aug. 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132311

ABSTRACT

Abstract This study was conducted to evaluate whether antibacterial pretreatment irrigation with silver nanoparticles (SNPs) and silver diamine fluoride (SDF) has any effect on bond strength of fiber posts cemented with three types of resin cements in root canal space. Fifty-four endodontically treated maxillary central incisor roots were prepared for fiber post (FRC Postec Plus NO.3, Ivoclar Vivadent) cementation and divided into nine groups in terms of three cement types and two pretreatments with silver antibacterial agents. The cements were as follows: an etch-and-rinse cement (ER, Excite DSC/Variolink N), a self-etch cement (SE, ED Primer/Panavia F2.0), and a self-adhesive cement (SA, Panavia SA Luting Plus). For each cement, the control group was with no treatment and two experimental groups were with SNPs and SDF treatments that were used after acid-etching for ER cement and after EDTA treatment for SE and SA cements. After fiber post cementation, each bonded root was horizontally sectioned into 1-mm thickness microslices to create two slices for each root region (apical, middle and coronal) and underwent push-out bond strength (PBS) test. Data in MPa were analyzed with two-way ANOVA and Tukey test (p=0.05). The interaction of the pretreatment type and cement type was significant (p<0.001). SNPs and SDF significantly increased PBS with ER cement (p≤0.04). This positive effect was also marginally significant for SDF with SE cement (p=0.049). For SA cement, SNPs showed a significant positive effect, but SDF had a significant adverse effect on PBS (p<0.001). The effect of pretreatment with silver antibacterial agents prior to adhesive cementation of fiber posts depends on the resin cement used. Contrary to SNPs with beneficial or no significant effect on bonding for all cements, SDF exhibited a deleterious effect with self-adhesive cement.


Resumo Este estudo foi conduzido para avaliar se a irrigação de pré-tratamento antibacteriano com nanopartículas de prata (SNPs) e fluoreto de diamina de prata (SDF) tem algum efeito na resistência de união de pinos de fibra cimentados com três tipos de cimentos resinosos no espaço do canal radicular. Cinquenta e quatro raízes de incisivos centrais superiores tratadas endodonticamente foram preparadas para cimentação de pino de fibra (FRC Postec Plus NO.3, Ivoclar Vivadent) e divididas em nove grupos em termos de três tipos de cimento e dois pré-tratamentos com agentes antibacterianos de prata. Os cimentos foram os seguintes: um cimento etch-and-rinse (ER, Excite DSC / Variolink N), um cimento autocondicionante (SE, ED Primer / Panavia F2.0) e um cimento autoadesivo (SA, Panavia SA Luting Plus). Para cada cimento, o grupo controle foi sem tratamento e dois grupos experimentais foram com SNPs e SDF tratamentos que foram usados após o condicionamento ácido para o cimento ER e após o tratamento com EDTA para os cimentos SE e SA. Após a cimentação do pilar de fibra, cada raiz ligada foi seccionada horizontalmente em microclimas de 1 mm de espessura para criar duas fatias para cada região da raiz (apical, média e coronal) e submetida ao teste de resistência de união por push-out (PBS). Os dados em MPa foram analisados ​​com ANOVA de dois fatores e teste de Tukey (p = 0,05). A interação do tipo de pré-tratamento e tipo de cimento foi significativa (p<0,001). SNPs e SDF aumentaram significativamente o PBS com cimento ER (p≤0,04). Este efeito positivo também foi marginalmente significativo para SDF com cimento SE (p = 0,049). Para o cimento SA, os SNPs mostraram um efeito positivo significativo, mas o SDF teve um efeito adverso significativo no PBS (p <0,001). O efeito do pré-tratamento com agentes antibacterianos de prata antes da cimentação adesiva dos pinos de fibra depende do cimento resinoso utilizado. Ao contrário dos SNPs com efeito benéfico ou nenhum efeito significativo na adesão para todos os cimentos, o SDF exibiu um efeito deletério com o cimento autoadesivo.


Subject(s)
Post and Core Technique , Dental Bonding , Metal Nanoparticles , Silver , Dentin , Anti-Bacterial Agents
10.
Article in Chinese | WPRIM | ID: wpr-828256

ABSTRACT

OBJECTIVE@#To explore the clinical efficacy of silver needle lumbar and sacral spine approach in treating gluteal muscle syndrome.@*METHODS@#Eighty-seven patients with gluteal muscle syndrome treated with silver needles in the Department of Rehabilitation Medicine of our hospital from September 2017 to September 2019 were selected. Except for symptoms of waist and hip pain and discomfort, all selected patients were examined by CT or MRI to confirm pathological imaging changes such as inflammatory exudation of the gluteal muscle. The 87 patients with gluteal muscle syndrome were divided into 2 groups according to the digital table method, and 42 patients in the lumbosacral approach group, including 19 males and 23 females, aged (50.70±12.45) years old, and disease duration of (1.63±1.27) years;45 cases in the buttock approach group, including 20 males and 25 females, aged (52.80±12.18) years old, with a course of disease of (1.78±1.22) years. The lumbosacral approach group was treated with spinal L to S bilateral articular process joints and L transverse process acupuncture needles, and the buttock approach group was treated with the gluteus medulla wing starting point and femoral trochanter stop. The VAS scores, soft tissue tenderness thresholds, and hip abductor muscle strength of the affected group were measured before and 4 weeks after treatment in the two groups. The clinical efficacy was also evaluated 4 weeks after treatment.@*RESULTS@#After 4 weeks, the VAS score of the lumbosacral approach group was 1.26±0.70, and the buttock approach group was 1.18±0.74, which were significantly lower than those before treatment, but there was no statistical difference between the groups (>0.05). The soft tissue tenderness threshold and ipsilateral hip abductor muscle strength were (5.51±0.70) kg and (10.34±2.19) kg in the lumbosacral approach group, and (4.78±1.05) kg, (9.33±1.42) kg in the buttock approach group. The results in the lumbosacral approach group was better than those in the buttock approach group(<0.05). The clinical efficacy of the lumbosacral approach group:16 cases got an excellent result, 20 good, 5 fair and 1 poor;in the buttock approach group, 13 excellent, 17 good, 12 fair and 3 poor. The clinical efficacy between the two groups had statistical difference (<0.05).@*CONCLUSION@#In the treatment of gluteus medius syndrome with silver needle, lumbosacral approach and buttock approach can effectively relieve the pain. Compared with the improvement of soft tissue tenderness threshold and hip abductor muscle strength, the upper lumbosacral approach is more prominent, and the overall clinical effect is more significant.


Subject(s)
Adult , Aged , Buttocks , Female , Humans , Male , Middle Aged , Muscle, Skeletal , Needles , Silver , Thigh
11.
Braz. arch. biol. technol ; 63: e20190339, 2020. graf
Article in English | LILACS | ID: biblio-1132187

ABSTRACT

Abstract Conventional orthodontic treatment with the use of stainless steel may be detrimental to oral health by promoting demineralizing lesions appearance and increasing adhesion and formation of bacterial biofilm, inducing the development of cavities. An alternative that has been researched to reduce the side effects of orthodontic treatment is the coating of materials with antimicrobial nanoparticles. Nanometric- sized particles increase their surface area and contact with the microbial membrane, consequently intensifying their bacteriostatic and bactericidal effect. In this work, hydrothermal synthesis, a "green" process was used to attach silver nanoparticles (AgNPs) to the surface of two different brands of orthodontic wires. The coated materials were analyzed for their physicochemical properties by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), which showed the distribution of AgNPs along the wires without modifying their properties. In the microbiological test, one of the brands showed a statistically significant difference in microbial adhesion and biofilm formation by Staphylococcus aureus and Streptococcus mutans. Results lead to the conclusion that antimicrobial orthodontic wires coated with silver nanoparticles through hydrothermal synthesis is a promising material for the improvement of orthodontic treatment.


Subject(s)
Orthodontic Wires , Staphylococcus aureus/drug effects , Streptococcus mutans/drug effects , Metal Nanoparticles , Anti-Bacterial Agents/pharmacology , Silver , Bacterial Adhesion , Calorimetry , Microscopy, Electron, Scanning , Dental Plaque , Linings
12.
Braz. arch. biol. technol ; 63: e20180614, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132182

ABSTRACT

Abstract The organic compound caffeine when detected in environmental matrices such as surface waters and groundwater is considered as an emerging contaminant, in which its effects are still unknown. Therefore, in the present research, zinc oxide-based catalysts impregnated with iron and silver were prepared for the reaction of caffeine degradation by heterogeneous photocatalysis. The wet impregnation method with excess solvent was applied to the preparation of the materials, later they were characterized by adsorption of N2, X-ray diffraction and photoacoustic spectroscopy. Then, the photodegradation, photolysis and adsorption tests were carried out, in which it was observed that only the presence of the radiation or photocatalysts could not sufficiently degrade the caffeine, however when combined radiation with all the catalysts studied here presented degradation above 70% at the end of 300 minutes of the reaction, and the best catalyst studied was that containing 8% Ag in non-calcined ZnO. Thus, these results point out that the methodology employed in this research, both for the preparation of the catalysts and in the process of the photocatalysis reaction, was efficient in the degradation of the emerging contaminant, caffeine, which could later be used for a mixture of other contaminants.


Subject(s)
Silver/chemistry , Zinc Oxide/chemistry , Caffeine/chemistry , Catalysis , Photochemical Processes , Adsorption , Bioreactors , Iron/chemistry
13.
Article in English | LILACS, BBO | ID: biblio-1056893

ABSTRACT

Abstract Objective: Current acceptability, barriers to use, and clinical/teaching practices of Silver Diamine Fluoride (SDF) among Brazilian dentists were investigated. Material and Methods: A Google forms questionnaire was sent to dentists (n=10,500) to collect information about the use of SDF and the dentists' workplace, experience, specialty, and city of practice. A logistic regression model was performed. Results: From 409 respondents, 13.2% used SDF. Working at universities increased the use of SDF by 2.29 times (p=0.018) compared to private offices. Each training year, the chance of SDF usage increased by 3% (p=0.008). Pediatric dentists are more likely to use SDF (OR=6.76, p<0.001). There is no association between SDF usage and the city of practice. The majority (75.9%) indicated SDF for noncompliant patients. Dentists (75.9%) reported the exclusive use in deciduous teeth, while 24.1% also use in permanent teeth. The main barrier for non-users was a lack of knowledge (58.3%), while for users, tooth staining (90.7%) and parental acceptance (64.8%) were the complaints. Conclusion: The Silver Diamine Fluoride is not a common product used by the dentists from RJ. Its clinical applicability should be further disseminated; thus, lack of scientific knowledge would cease to be a problem in the use of SDF to arrest caries lesions.


Subject(s)
Humans , Brazil/epidemiology , Cariostatic Agents , Health Knowledge, Attitudes, Practice , Dental Caries , Dentists , Silver , Logistic Models , Cross-Sectional Studies/methods , Surveys and Questionnaires
14.
Afro-Egypt. j. infect. enem. Dis ; 1(1): 15-23, 2020. ilus
Article in English | AIM, AIM | ID: biblio-1258716

ABSTRACT

Background: The growing incidence of multidrug resistant (MDR) bacterial infections has become a public health crisis. This work aims to evaluate the in-vitro activity of silver nanoparticles (AgNPs), alone and in combination with the antimicrobials amikacin and ceftazidime, against MDR Gram-negative bacilli (GNB) isolated from clinical cases in Zagazig University Hospitals. Methods: In a cross sectional study, MDR GNB were isolated from different clinical specimens and were tested to determine the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal activity of AgNPs using broth microdilution method. The effect of combining subMIC levels of AgNPs (MIC/2 and MIC/4) with amikacin and ceftazidime, was also determined by broth microdilution. Results: A total of 63 MDR GNB was obtained during the study period (22 E. coli, 17 Klebsiella, 15 Pseudomonas aeruginosa and 9 Acinetobacter isolates). AgNPs demonstrated a bactericidal effect on all tested isolates with an MBC/MIC ratio of less than 4. When combined with amikacin, a synergistic effect was demonstrated on all tested E.coli and Klebsiella isolates at AgNPs MIC/2 and on 45.4%, 40% and 77.8% of E.coli, P.aeruginosa and Acinetobacter isolates, respectively at MIC/4. In combination with ceftazidime, AgNPs exhibited a synergistic effect on 100% of E. coli and 88.2% Klebsiella at both MIC/2 and MIC/4 and on 40% of P. aeruginosa isolates at AgNPs MIC/4. Conclusions: AgNPs exert a bactericidal activity on MDR GNB as well as a synergistic effect when combined with amikacin and ceftazidime suggesting them as a new weapon in the war against MDR GNB


Subject(s)
Drug Resistance, Multiple , Egypt , Enterobacteriaceae , Nanoparticles , Silver
15.
Afro-Egypt. j. infect. enem. Dis ; 1(2): 77-85, 2020. ilus
Article in English | AIM, AIM | ID: biblio-1258719

ABSTRACT

Background: Multi-drug resistant (MDR) bacteria are seriously endangering the antibiotics. Different alternative strategies are needed to reinforce antibiotics, of, these; nanostructured materials may play a fruitful role. This study aimed to investigate the antibacterial and antibiofilm activity of silver nanoparticles (AgNPs) against MDR bacteria. Methods: In a cross-sectional study, a total of 33 methicillin resistant Staphylococcus aureus (MRSA) and 52 MDR Pseudomonas aeruginosa (P. aeruginosa) isolates were recovered from intensive care units' (ICUs) admitted patients over a period of 9 months, from December 2017 to August 2018. The antibacterial activity of AgNPs on the clinical isolates of MRSA and MDR P. aeruginosa was assessed by minimum inhibitory concentrations (MICs) using broth microdilution method. The minimum bactericidal concentrations (MBCs) were determined as the lowest concentrations required to kill 99.9% of the initial inoculum. Tissue culture plate method was used to evaluate the antibiofilm activity. Results: The MIC and MBC values ranged from 1 to 16 µg/ml and 2 to 64 µg/ml, respectively. Silver nanoparticles exerted a significant antibiofilm activity against MRSA and MDR P.aeruginosa at all tested concentrations, recording a maximum inhibition value of (82%) and (91%), respectively. Conclusions: AgNPs exhibited a considerable antibacterial and antibiofilm, effect; it could represent a promising weapon in the fight against biofilm forming MDR organisms


Subject(s)
Egypt , Methicillin-Resistant Staphylococcus aureus , Nanoparticles , Pseudomonas aeruginosa , Silver , Tuberculosis, Multidrug-Resistant
16.
Braz. dent. j ; 30(6): 607-616, Nov.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1055448

ABSTRACT

Abstract Diamond-like carbon (DLC) film is a biocompatible hard coating material that can prevent the leaching of metal ions. This study evaluates the structural characteristics of DLC, with and without silver nanoparticles, deposited by plasma (PECVD) on titanium alloy (Ti-6Al-4V) and bone formation in contact with DLC films. Sixty Ti-6Al-4V samples were used divided in: uncoated, coated with DLC and coated with DLC-Ag. After structural characterization, samples were fixed bilaterally at the rabbit's mandible. After 15 and 90 days, samples were characterized again and bone formation in the area was analyzed by histomorphometry. Statistical analysis was performed by two-way ANOVA. Both the DLC and DLC-Ag films were firmly adhered and showed a high electrical resistance without significant changes in the Raman spectrum after in vivo integration. After 15 days, there were immature bone trabeculae in the interface and partially covering the surface. After 90 days, mature bone filled the interface and coved the surface. There was no statistically significant difference among the three groups in both periods. In conclusion, osseointegration with DLC, DLC-Ag and uncoated Ti-6Al-4V is similar. However, DLC and DLC-Ag coverings have the advantage of electrical insulation and can presumably control bacterial activity and ion leaching.


Resumo O filme de carbono semelhante a diamante (DLC) é um material de revestimento duro e biocompatível que pode impedir a corrosão com liberação de íons metálicos. Este estudo avaliou as características estruturais do filme de DLC, com e sem nanopartículas de prata (Ag), depositadas por plasma (PECVD) em liga de titânio (Ti-6Al-4V) e formação óssea em contato com filmes de DLC. Foram utilizadas 60 amostras de Ti-6Al-4V divididas em: não recobertas, recobertas com DLC e recobertas com DLC-Ag. Após caracterização estrutural, amostras foram fixadas bilateralmente na mandíbula de coelhos. Após 15 e 90 dias, as amostras foram novamente caracterizadas e a formação óssea na área foi analisada por histomorfometria. A análise estatística foi realizada por ANOVA dois fatores. Ambos os filmes DLC e DLC-Ag foram firmemente aderidos e mostraram uma alta resistência elétrica sem alterações significativas no espectro Raman após a osseointegração in vivo. Após 15 dias, havia trabéculas ósseas imaturas na interface e cobrindo parcialmente a superfície. Após 90 dias, o osso maduro preencheu a interface e a superfície. Não houve diferença estatisticamente significante entre os três grupos nos dois períodos. Em conclusão, a osseointegração com DLC, DLC-Ag e Ti-6Al-4V não revestido é similar. No entanto, os revestimentos DLC e DLC-Ag têm a vantagem do isolamento elétrico e podem presumivelmente controlar a atividade bacteriana e a corrosão com liberação de íons.


Subject(s)
Animals , Rabbits , Alloys , Metal Nanoparticles , Silver , Surface Properties , Titanium , Materials Testing , Carbon , Diamond
17.
Rev. argent. microbiol ; 51(2): 103-109, jun. 2019. ilus, graf, tab
Article in English | LILACS | ID: biblio-1013358

ABSTRACT

In the present work, the biosynthesis of silver-nanoparticles (AgNP) was evaluated using the aqueous extract from Justicia spicigera. The obtained silver nanoparticles were characterized using UV-visible spectroscopic techniques, energy dispersive X-ray spectrometers (EDS), zeta potential and dynamic light scattering. The antimicrobial activity of biosynthesized AgNP was tested against foodborne bacteria (Bacillus cereus, Klebsiella pneumoniae and Enterobacter aerogenes) and phytopathogenic fungi (Colletotrichum sp., Fusarium solani, Alternaria alternata and Macrophomina phaseolina). The elemental profile of synthesized nanoparticles using J. spicigera shows higher counts at 3 keV due to silver, confirming the formation of silver nanoparticles. Scanning electron microscopy (SEM) analysis showed a particle size between 86 and 100 nm with spherical morphology. AgNP showed effective antibacterial and antifungal activity against the tested organisms principally with B. cereus, K. pneumoniae, E. aerogenes, A. alternata and M. phaseolina. Therefore, further studies are needed to confirm the potential of AgNP from J. spicigera in the control of indicator organisms under field conditions.


En el presente trabajo se evaluó la biosíntesis de nanopartículas de plata (AgNP) en presencia de una sal de plata y extractos acuosos de Justicia spicigera. Las nanopartículas así obtenidas fueron caracterizadas mediante técnicas espectroscópicas UV-visibles, espectrómetros de rayos X de energía dispersiva (EDS), potencial zeta y dispersión de luz dinámica. La actividad antimicrobiana de las AgNP biosintetizadas se probó frente a diversas bacterias transmitidas por alimentos (Bacillus cereus, Klebsiella pneumoniae y Enterobacter aerogenes) y hongos fitopatógenos (Colletotrichum sp., Fusarium solani, Alternaria alternata y Macrophomina phaseolina). El perfil elemental de las nanopartículas sintetizadas utilizando el extracto de J. spicigera mostró valores altos a 3 keV, lo que confirma la formación de nanopartículas de plata. El análisis por microscopía electrónica de barrido (SEM) reveló un tamaño de partícula entre 86 y 100 nm, con morfología esférica. Las AgNP mostraron una actividad antibacteriana y antifúngica efectiva contra los organismos evaluados, principalmente contra B. cereus, K. pneumoniae, E. aerogenes, A. alternata y M. phaseolina. Se necesitan más estudios para confirmar el potencial de las AgNP derivadas de J. spicigera en el control de organismos indicadores en condiciones de campo.


Subject(s)
Silver/therapeutic use , Pest Control, Biological , Metal Nanoparticles/analysis , Foodborne Diseases/microbiology , Foodborne Diseases/prevention & control , Anti-Infective Agents , Antifungal Agents
18.
Braz. dent. j ; 30(2): 106-116, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-1001439

ABSTRACT

Abstract The aim of this study was to evaluate the push-out bond strength and interface permeability of glass-fiber posts in different regions of post space (cervical, middle, and apical) submitted to different irrigation solutions. Ninety single-rooted human teeth were submitted to endodontic treatment and divided into five groups, according to irrigation solutions: distilled water, 5.25% NaOCl, 25% polyacrylic acid, 2% chlorhexidine, and 23 ppm Ag NP dispersion. Each group was divided in 3 subgroups (n=6) according to cementation: SBU: Adper Scotchbond Universal + RelyX ARC; U200: RelyX U200; MCE: MaxCem Elite. Bond strength and sealing ability were measured in different areas of post space. The data was subjected to ANOVA and Fisher's test (a=0,05). The silver nanoparticle solution showed highest bond strength values and lowest interface permeability in all thirds analyzed for SBU group. In the U200 group, the highest bond strength values were found for sodium hypochlorite solution, with significant difference between this solution and polyacrylic acid. A decrease in bond strength values in cervical to apical direction was found for MCE group and the same behavior were found for others groups. Regarding interface permeability, use of silver nanoparticle solution resulted in lower values in cervical and apical thirds. There was a decrease in bond strength in cervical to apical direction. Different irrigation solutions and intraradicular depth influenced the bond strength and interface permeability of adhesive material to dentin substrate. Silver nanoparticle solution can effectively be used as an irrigation agent in post space prior to fiber post cementation process.


Resumo O objetivo deste trabalho foi avaliar a resistência de união e permeabilidade da interface de pinos de fibra de vidro nos diferentes terços da dentina intrarradicular (cervical, médio e apical) submetidos a diferentes agentes irrigantes. Noventa dentes unirradiculares humanos foram submetidos ao tratamento endodôntico e foram divididos em cinco grupos de acordo com os agentes irrigantes: água destilada, hipoclorito de sódio 5,25%, ácido poliacrílico 25%, clorexidina 2% e dispersão de nanopartícula de prata à 23 ppm. Os grupos foram divididos em 3 subgrupos (n=6) de acordo com a técnica adotada para cimentação adesiva dos pinos de fibra de vidro: Grupo SBU: sistema adesivo ScotchbondTM Universal + cimento resinoso RelyX ARC; Grupo U200: cimento resinoso autoadesivo RelyX U200; Grupo MCE: cimento resinoso autoadesivo Maxcem Elite. A resistência de união e a permeabilidade da interface foram mensurados em diferentes áreas da dentina intrarradicular. Os dados foram submetidos a ANOVA e teste de Fisher (a=0,05). Amostras representativas foram levadas à microscopia eletrônica de varredura. A solução de nanopartícula de prata apresentou os maiores valores de resistência de união em todos os terços analisados para o grupo SBU. No grupo U200, os maiores valores foram encontrados para a solução de hipoclorito de sódio, com diferença para o ácido poliacrílico. Observou-se uma diminuição nos valores de resistência de união na direção cérvico-apical para o grupo MCE e o mesmo comportamento foram encontrados para os demais grupos. Com relação a permeabilidade da interface, o uso da solução de nanopartícula de prata resultou em menores valores nos terços cervical e apical. Houve diminuição dos valores de resistência de união no sentido cérvico-apical. As diferentes soluções irrigantes, bem como a profundidade intrarradicular influenciaram a resistência de união e permeabilidade da interface dos materiais adesivos ao substrato dentinário. A nanopartícula de prata pode ser utilizada como agente irrigador do conduto radicular previamente à cimentação de pinos de fibra de vidro.


Subject(s)
Humans , Post and Core Technique , Dental Bonding , Metal Nanoparticles , Silver , Materials Testing , Resin Cements , Dentin , Glass
19.
Article in English | WPRIM | ID: wpr-719616

ABSTRACT

BACKGROUND: Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancers have emerged as key predictive biomarkers in EGFR tyrosine kinase inhibitor (TKI) treatment. However, a few patients with wild-type EGFR also respond to EGFR TKIs. This study investigated the factors predicting successful EGFR TKI treatment in lung adenocarcinoma patients with wild-type EGFR. METHODS: We examined 66 patients diagnosed with lung adenocarcinoma carrying wide-type EGFR who were treated with EGFR TKIs. The EGFR gene copy number was assessed by silver in situ hybridization (SISH). We evaluated the clinical factors and EGFR gene copy numbers that are associated with a favorable clinical response to EGFR TKIs. RESULTS: The objective response rate was 12.1%, while the disease control rate was 40.9%. EGFR SISH analysis was feasible in 23 cases. Twelve patients tested EGFR SISH-positive, and 11 were EGFR SISH-negative, with no significant difference in tumor response and survival between EGFR SISH-positive and -negative patients. The overall median progression-free survival (PFS) and overall survival (OS) of 66 patients were 2.1 months and 9.7 months, respectively. Female sex and Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0–1 were independent predictors of PFS. ECOG PS 0–1 and a low tumor burden of extrathoracic metastasis were independent predictors of good OS. CONCLUSION: Factors such as good PS, female sex, and low tumor burden may predict favorable outcomes following EGFR TKI therapy in patients with EGFR wild-type lung adenocarcinoma. However, EGFR gene copy number was not predictive of survival.


Subject(s)
Adenocarcinoma , Biomarkers , Disease-Free Survival , Female , Genes, erbB-1 , Humans , In Situ Hybridization , Lung Neoplasms , Lung , Neoplasm Metastasis , Protein-Tyrosine Kinases , ErbB Receptors , Silver , Tumor Burden
20.
Article in English | WPRIM | ID: wpr-742000

ABSTRACT

OBJECTIVES: This study evaluated the effect of dentin pretreatment with silver nanoparticles (SNPs) and chlorhexidine (CHX) on the microshear bond strength (µSBS) durability of different adhesives to dentin. MATERIALS AND METHODS: Occlusal surfaces of 120 human molars were ground to expose flat dentin surfaces. The specimens were randomly assigned to six groups (n = 20). Three groups (A, B, and C) were bonded with Adper Single Bond 2 (SB) and the other groups (D, E, and F) were bonded with Clearfil SE Bond (SEB). Dentin was pretreated with CHX in groups B and E, and with SNPs in groups C and F. The specimens were restored with Z250 composite. Half of the bonded surfaces in each group underwent µSBS testing after 24 hours and the other half was tested after 6 months of water storage. RESULTS: SNP application was associated with a higher µSBS than was observed in the CHX and control groups for SEB after 24 hours (p < 0.05). A significantly lower µSBS was observed when no dentin pretreatment was applied compared to dentin pretreatment with CHX and SNPs for SB after 24 hours (p < 0.05). The µSBS values of the 6-month specimens were significantly lower than those obtained from the 24-hour specimens for all groups (p < 0.05). This decrease was much more pronounced when both adhesives were used without any dentin pretreatment (p < 0.05). CONCLUSIONS: SNPs and CHX reduced the degradation of resin-dentin bonds over a 6-month period for both adhesive systems.


Subject(s)
Adhesives , Chlorhexidine , Dentin , Humans , Molar , Nanoparticles , Polymorphism, Single Nucleotide , Silver , Water
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