Antibacterial efficacy of chemically and plant-synthesized zinc oxide nanocomposite against Staphylococcus aureus and Escherichia coli inoculated in Tilapia fillet

Aims@#Edible coatings developed from biodegradable materials such as starch and zinc oxide nanoparticles (ZnO-NPS) are efficient antimicrobials that could be used as a food additive to reduce the bacterial load on the food surface. Therefore, this study was aimed to examine the effect of chemical and green synthesized ZnO-NPS with different concentrations on the survival of Escherichia coli and Staphylococcus aureus in fish fillets during chilling storage at 4 ± 1°C.@*Methodology and results@#ZnO-NPS were chemically prepared by mixing zinc acetate dihydrate with sodium hydroxide. Lavandula officinalis was used for the green synthesis of ZnO-NPS. The sterile biodegradable coating containing 2 and 5% of both chemically and green synthesized ZnO-NPS were made using starch, gelatin, xanthan gum and glycerol. Different bacterial cocktail strains of both E. coli and S. aureus were inoculated onto Tilapia fillet samples. The coating solution with different antimicrobials was aseptically spread in Tilapia fillets and examined periodically within two days intervals for the survival of S. aureus and E. coli during chilling at 4 ± 1 °C. Both chemically and plantsynthesized ZnO-NPS reduced the growth of both S. aureus and E. coli by about 3.7 log10 CFU/cm2 of Tilapia fillet. The incorporation of L. officinalis increased the antibacterial activity of ZnO-NPS. Staphylococcus aureus was more sensitive than E. coli for both chemically and plant-synthesized ZnO-NPS. Moreover, zinc oxide biodegradable coating extended the shelf-life of chilled Tilapia fillets by about 4 days.@*Conclusion, significance and impact of study@#The results of the current study demonstrated the incorporation of L. officinalis into ZnO-NPS biodegradable coating which may be promising in reducing microbial growth on food surfaces.

The toxicity of ZnO and CuO nanoparticles on biological wastewater treatment and its detoxification: a review / 生物工程学报

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.

Assessment of zinc solubilization potential of zinc-resistant Pseudomonas oleovorans strain ZSB13 isolated from contaminated soil / Avaliação do potencial de solubilização do zinco da cepa ZSB13 de Pseudomonas oleovorans resistente ao zinco isolada de solo contaminado

Zinc is an essential micronutrient that is required for optimum plant growth. It is present in soil in insoluble forms. Bacterial solubilization of soil unavailable form of Zn into available form, is an emerging approach to alleviate the Zn deficiency for plants and human beings. Zinc solubilizing bacteria (ZSB) could be a substitute for chemical Zn fertilizer. The present study aimed to isolate and characterize bacterial species from the contaminated soil and evaluate their Zn solubilizing potential. Zn resistant bacteria were isolated and evaluated for their MIC against Zn. Among the 13 isolated bacterial strains ZSB13 showed maximum MIC value upto 30mM/L. The bacterial strain with the highest resistance against Zn was selected for further analysis. Molecular characterization of ZSB13 was performed by 16S rRNA gene amplification which confirmed it as Pseudomonas oleovorans. Zn solubilization was determined through plate assay and broth medium. Four insoluble salts (zinc oxide (ZnO), zinc carbonate (ZnCO3), zinc sulphite (ZnS) and zinc phosphate (Zn3(PO4)2) were used for solubilization assay. Our results shows 11 mm clear halo zone on agar plates amended with ZnO. Likewise, ZSB13 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8 ppm) and ZnO (18.2 ppm). Furthermore, Zn resistance genes czcD was also enriched in ZSB13. In our study, bacterial strain comprising Zn solubilization potential has been isolated that could be further used for the growth enhancement of crops.

O zinco é um micronutriente essencial necessário para o crescimento ideal das plantas. Ele está presente no solo em formas insolúveis. A solubilização bacteriana da forma indisponível de Zn no solo para a forma disponível é uma abordagem emergente para aliviar a deficiência de Zn em plantas e seres humanos. Bactérias solubilizadoras de zinco (ZSB) podem ser um substituto para fertilizantes químicos de Zn. O presente estudo teve como objetivo isolar e caracterizar espécies bacterianas de solo contaminado e avaliar seu potencial de solubilização de Zn. Bactérias resistentes ao Zn foram isoladas e avaliadas quanto ao seu MIC contra o Zn. Entre as 13 cepas bacterianas isoladas, ZSB13 apresentou valor máximo de MIC de até 30 mM/L. A cepa bacteriana com maior resistência ao Zn foi selecionada para análise posterior. A caracterização molecular de ZSB13 foi realizada por amplificação do gene 16S rRNA que o confirmou como Pseudomonas oleovorans. A solubilização do Zn foi determinada através de ensaio em placa e meio caldo. Quatro sais insolúveis (óxido de zinco (ZnO), carbonato de zinco (ZnCO3), sulfito de zinco (ZnS) e fosfato de zinco (Zn3 (PO4) 2) foram usados para o ensaio de solubilização. Nossos resultados mostram uma zona de halo clara de 11 mm em placas de ágar corrigidas com ZnO. Da mesma forma, ZSB13 mostrou liberação significativa de Zn em caldo alterado com ZnCO3 (17 e 16,8 ppm) e ZnO (18,2 ppm). Além disso, os genes de resistência ao Zn czcD também foram enriquecidos em ZSB13. Em nosso estudo, a cepa bacteriana compreendendo potencial de solubilização de Zn foi isolada e poderia ser usada posteriormente para o aumento do crescimento de safras.

Effects of chemical and green nano-zinc oxide on histological changes, oxidative stress, and apoptosis in rat kidney associated with cisplatin

Abstract Cisplatin (CP) is used to treat various tumors. A main restriction of cisplatin is nephrotoxicity. This study aimed to evaluate the protective effects of ZnONPs on cisplatin-induced oxidative stress and rat kidney tissue damage. Eighty adult male Wistar rats (250g-270g) were divided into ten groups: Control (CON), Sham (SH), Bulk ZnO (BZnO), Chemical ZnONPs (ChZnONPs), Green ZnONPs (GrZnONPs), Cisplatin (CP), Cisplatin+BulkZnO (CP+BZnO), Cisplatin+Green ZnONPs (CP+GrZnONPs), Cisplatin+Chemical ZnONPs (CP+ChZnONPs), Cisplatin+Explant (CP+EX). CP was i.p administered 5mg/kg/week and BZnO, ChZnONPs and GrZnONPs were i.p administered at a dose of 5mg/kg/day. After 30 days of the treatment, the expression of apoptosis/anti apoptosis related genes oxidant/antioxidant factors and histological changes in the were studied. The CP-treated group showed a decrease in body weight, while the Co-administration of ZGNPs to CP-treated rats showed a significant increase compared to the CP group. The results showed that the increased mRNA level of bax, MDA and the decreased mRNA level of bcl2, SOD and CAT activities in kidney of CP group were improved when animals were treated with ZnO NPs. Our results showed that GrZnONPs, ChZnONPs and BZnO had the potential to protect against oxidative stress and cisplatin-induced neurotoxicity that this protective effect was more evident in GrZnONPs.

Zinc oxide nanoparticles synthesized using Hyssopus Officinalis L. Extract Induced oxidative stress and changes the expression of key genes involved in inflammatory and antioxidant Systems

BACKGROUND: Recent advances in the synthesis of bioactive nanoparticles resulted in the discovery and introduction of new bioactive nanoparticles to the pharmaceutical industry. In this regard, this research is aimed to synthesize the zinc oxide nanoparticles (ZnO-NPs) using Hyssopus officinalis L. extract and to evaluate the safety of nanoparticles using Balb/C mice. METHODS: Forty male mice were divided into four groups and received 0, 50, 100, and 200 mg/kg of ZnO-NPs for thirty days. At the end of the experiment, blood sugar, creatinine, aspartate aminotransferase (A.S.T.), and alanine aminotransferase (A.L.T.) were determined. Furthermore, histopathological and oxidative stress biomarker analyses in liver and kidney tissues were performed. The changes in the major inflammatory- and antioxidant-related genes were determined. RESULTS: The results showed that blood sugar and creatinine reduced significantly (P < 0.05) when 50, 100, and 200 mg/kg ZnO-NPs were supplemented to the diet. The serum ALT and AST and lipid peroxidation in the liver and kidney tissues were increased significantly (p < 0.05) when 50, 100, and 200 mg/kg ZnO-NPs were supplemented to the diet. Supplementation of ZnO-NPs suppressed the expression of antioxidant-related genes (SOD and CAT) and up-regulated the inflammatory biomarkers (iNOS and TNF- α). The concentration of 200 mg/Kg nanoparticles indicated cellular degeneration and necrosis in the liver and kidney tissues. CONCLUSIONS: Overall, it can be concluded that supplementation of ZnO-NPs synthesized using Hyssopus Officinalis L. extract in this study at 50 mg/kg or higher concentrations might be toxic to the mice.

Pasta CTZ para abordaje endodóncico de dientes primarios: Una revisión narrativa de la literatura / Pasta CTZ na abordagem endodôntica de dentes decíduos: uma revisão de literatura / CTZ paste for endodontic approach to deciduous teeth: A literature review

Introducción:La afectación pulpar irreversible de los dientes primarios representa un desafío para la endodoncia en odontopediatría. Sobre la base del enfoque de esterilización de lesiones y reparación de tejidos (LSTR- Lesion Sterelization and Tissue Repair), se ha propuesto una técnica endodóncica no instrumental que utiliza pastas antibióticas. La pasta antibiótica CTZ, que contiene una mezcla de cloranfenicol, tetraciclina, óxido de zinc y eugenol, tiene potencial para uso en la técnica endodóncica no instrumental en pacientes pediátricos. Objetivo: El objetivo de este trabajo es presentar una revisión narrativa de la literatura sobre la pasta antibiótica CTZ, en lo relacionado a capacidad antimicrobiana, biocompatibilidad y aspectos clínicos. Materiales y métodos: Se realizaron búsquedas en las bases de datos PUBMED, BVS, WEB OF SCIENCE, COCHRANE y SCOPUS utilizando los términos "ctz paste", "ctz", "tooth, deciduous" y "primary molars" sin restricción de idioma, con fecha limitada de 2015 hasta enero de 2021. Resultados: Después de eliminar los duplicados, se obtuvieron 13 artículos. La pasta CTZ mostró una actividad antimicrobiana satisfactoria en Enterecoccus faecalis, Staphylococcus aureus, Klebisiella pneumonia, Escherichia coli y Candida albicans. Los estudios in vitro e in vivo han demostrado que la pasta tiene biocompatibilidad. La frecuencia de éxito clínico varió del 37% al 100% y el éxito radiográfico del 29,7% al 97,4%. Conclusiones: Aunque se necesitan más estudios que contribuyan a un mejor nivel de la evidencia, puede afirmase que la pasta CTZ una es alternativa para los casos de afectación pulpar en dientes primarios, inclusive en el ámbito de la salud pública

Introdução: O envolvimento pulpar irreversível dos dentes decíduos, representa um desafio à endodontia em odontopediatria. Com base na abordagem de esterilização da lesão e reparo tecidual (LSTR- Lesion Sterelization and Tissue Repair), a técnica endodôntica não instrumental com utilização de pastas antibióticas tem sido proposta. A pasta antibiótica CTZ, que contém uma mistura de cloranfenicol, tetraciclina, óxido de zinco e eugenol, apresenta potencial para uso na técnica endodôntica não instrumental em pacientes pediátricos. Objetivo: O objetivo deste trabalho é apresentar uma revisão narrativa da literatura sobre a pasta antibiótica CTZ, abrangendo capacidade antimicrobiana, biocompatibilidade e aspectos clínicos. Materiais e métodos: Foi realizada busca nas bases de dados PUBMED, BVS, WEB OF SCIENCE, COCHRANE e SCOPUS usando os termos "ctz paste", "ctz", "tooth, deciduous" e "primary molars" com data limitada de 2015 a janeiro de 2021. Resultados: Após a remoção de duplicatas 13 artigos foram obtidos. A pasta CTZ mostrou atividade antimicrobiana satisfatória sobre Enterecoccus faecalis, Staphylococcus aureus, Klebisiella pneumonia, Escherichia coli y Candida albicans. Estudos in vitro e in vivo demonstraram que a pasta apresenta boa biocompatibilidade. A frequência de sucesso clínico variou de 37% a 100% e o sucesso radiográfico de 29,7% a 97,4%. Conclusão: Embora mais estudos que contribuam para um melhor nível de evidência sejam necessários, a pasta antibiótica CTZ apresenta atividade antimicrobiana, biocompatibilidade e resultados clínicos satisfatórios, podendo ser uma alternativa interessante para os casos de comprometimento pulpar de dentes decíduos, inclusive em saúde pública

Introduction: The irreversible pulp changes in primary teeth represent a challenge to endodontics in pediatric dentistry. Based on the Lesion Sterilization and Tissue Repair approach (LSTR), a non-instrumental endodontic treatment (NIET) of primary teeth root canals using an antibiotic paste has been proposed. The CTZ antibiotic paste, which contains a mixture of chloramphenicol, tetracycline, zinc oxide and eugenol, has potential for use in pediatric patients. Objective: The objective of this work is to present a literature review on the CTZ antibiotic paste, covering antimicrobial capacity, biocompatibility, and clinical aspects. Methods: An electronic search on PUBMED, BVS, WEB OF SCIENCE, COCHRANE y SCOPUS databases using the terms "ctz paste", "ctz", "deciduous teeth" and "primary molars" without language restrictions and publication date between 2015 and January 2021. Results: After removing duplicates, a total of 13 articles were included. The CTZ paste showed satisfactory antimicrobial activity on Enterecoccus faecalis, Staphylococcus aureus, Klebisiella pneumonia, Escherichia coli andCandida albicans. In vivo and in vitro studies have demonstrated that the paste presents good biocompatibility. The frequency of clinical success varied from 37% to 100% and radiographic success from 29,7% to 97,4%. Conclusion: Although more studies are needed to contribute to the body of evidence, the CTZ antibiotic paste demonstrated antimicrobial activity, biocompatibility and satisfactory clinical results and may be an alternative for cases of pulp involved primary teeth, including in public health.

Comparação de diferentes técnicas e pastas obturadoras em pulpectomias de dentes decíduos bovinos: estudo in vitro / Comparison of different techniques and obtaining paste in bovine decidual teeth pulpectomies: in vitro study

A manutenção dos dentes decíduos na cavidade bucal até o período de sua esfoliação fisiológica é de extrema importância. A terapia endodôntica é um tratamento indicado quando a saúde do tecido pulpar é comprometida e diversas técnicas e materiais podem ser empregados para realizar a obturação de canais radiculares. O objetivo deste estudo in vitro foi comparar a qualidade do preenchimento dos canais radiculares utilizando diferentes técnicas de obturação e pastas obturadoras em dentes decíduos bovinos submetidos à pulpectomia. Foram selecionados 30 incisivos decíduos bovinos, e preparados através da técnica manual com posterior obturação dos canais radiculares por meio de duas técnicas e três pastas obturadoras. Os dentes foram divididos em 6 grupos (n= 5/ grupo) da seguinte forma: GI ­ Técnica manual e pasta de Hidróxido de Cálcio PA espessada com Óxido de Zinco; GII ­ Técnica manual e pasta Guedes-Pinto Modificada; GIII ­ Técnica manual e pasta Feapex®; GIV ­ Técnica com auxílio da lentulo e pasta de Hidróxido de Cálcio PA espessada com Óxido de Zinco; GV ­ Técnica com auxílio da lentulo e pasta Guedes-Pinto Modificada; GVI ­ Técnica com auxílio da lentulo e pasta Feapex®. Foram realizadas as radiografias digitais para verificar a qualidade do preenchimento dos canais radiculares. Os resultados obtidos apresentaram diferenças significativas na qualidade do preenchimento dos canais radiculares entre os grupos de dentes decíduos bovinos obturados. Considerando os resultados obtidos e a metodologia empregada, pode-se concluir que existe diferença entre as técnicas de obturação e pastas obturadoras(AU)

Maintaining primary teeth in the oral cavity until the period of their physiological exfoliation is extremely important. An endodontic therapy is a treatment indicated when the health of the pulp tissue is compromised and several techniques and materials can be used to perform root canal filling. The aim of this in vitro study was to compare the quality of root canal filling using different filling techniques and filling masses in primary bovine teeth implanted under pulpectomy. Thirty bovine primary incisors were selected and prepared using the manual technique with subsequente filling of the root canals using two techniques and three filling materials. The teeth were divided into 6 groups (n= 5 / group) as follows: GI - Technical Manual and Calcium Hydroxide Mass PA thickened with Zinc Oxide; GII - Manual technique and modified Guedes-Pinto pasta; GIII - Manual technique and Feapex® paste; GIV - Technique with the aid of lentulo and mass of Calcium Hydroxide PA thickened with Zinc Oxide; GV ­ Technique with the aid of lentulo and modified Guedes-Pinto mass; GVI - Technique with the aid of lentulo and Feapex® mass. Digital radiographs were taken to check the quality of the filling of the root canals. The resulting results dissipated in the quality of filling the root canals between the groups of primary bovine teeth filled. Know the results obtained and the methodology used, it can be concluded that there is a difference between filling techniques and filling masses(AU)

A randomized controlled study on the efficacy and safety of zinc oxide 20% ointment versus salicylic acid 15% + lactic acid 15% ointment in the treatment of patients with Verruca vulgaris in a tertiary hospital

Background@#Verruca vulgaris are scaly, rough papules or nodules caused by the human papilloma virus.@*Objective@#To determine the efficacy and safety of topical zinc oxide ointment versus topical salicylic acid + lactic acid ointment as treatment among patients with verruca vulgaris.@*Methods@#This randomized, double-blind, 6-week study involved 29 patients with verruca vulgaris in a tertiary center who received zinc oxide 20% ointment or salicylic acid 15% + lactic acid 15% ointment applied daily and occluded with LeukoplastTM tape. Evaluation was done every two weeks.@*Results@#There was significant decrease in number of warts in the zinc oxide group (p=0.004), while it was not significant in the salicylic acid+lactic acid group (p=0.392). Comparison between the two groups was not significant (p>0.05). Both zinc oxide (P=0.000) and salicylic acid+lactic acid groups (P=0.025) had significant decrease in size of warts from baseline to 6th week of observation. No significant differences were observed between the two groups in terms of adverse events such as erythema (P>0.05), edema (P>0.05), tenderness (P>0.05), and scaling (P>0.05); however, itching was significantly higher at 4th week in the salicylic acid+lactic acid group B (16.7%). Among the zinc oxide group, 100% would recommend the treatment, while only 71.4% would recommend salicylic acid+lactic acid. The satisfaction levels of zinc oxide group were also statistically higher than salicylic acid+lactic acid group (p=0.000).@*Conclusion@#Zinc oxide 20% ointment is a safe and effective option for the treatment of verruca vulgaris especially among patients that would prefer non-traumatic measures in the removal of their warts.

Evaluation of the Genotoxicity of Endodontic Materials for Deciduous Teeth Using the Comet Assay

ABSTRACT Objective: To evaluate genotoxicity of zinc oxide, P. A. calcium hydroxide, mineral trioxide aggregate and an iodoform paste using comet assay on human lymphocytes. Material and Methods: Two positive controls were used: methyl-methanesulfonate for the P.A. calcium hydroxide and mineral trioxide aggregate; and doxorubicin for the iodoform paste and zinc oxide. There were also two negative controls: distilled water for the P.A. calcium hydroxide and mineral trioxide aggregate; and DMSO for the iodoform paste and zinc oxide. Comets were identified using fluorescence microscopy and 100 of them were counted on each of the three slides analyzed per drug test. A damage index was established, taking into consideration the score pattern that had previously been determined from the size and intensity of the comet tail. Analysis of variance, followed by Tukey's test, was used to compare the means of the DNA damage indices. Results: The DNA damage index observed for mineral trioxide aggregate (7.08 to 8.58) and P.A. calcium hydroxide (6.50 to 8.33), which were similar to negative control index. On the other hand, damage index for zinc oxide (104.7 to 218.50) and iodoform paste (115.7 to 210.7) were similar to positive control index. Conclusion: Iodoform paste and zinc oxide showed genotoxicity at all concentrations used.

Evaluation of zinc-oxide nanocoating on the characteristics and antibacterial behavior of nickel-titanium alloy

ABSTRACT Objective: To investigate the effect of ZnO nanocoating on mechanical properties of NiTi orthodontic wires and antibacterial activity. Methods: 0.016 x 0.022-in NiTi orthodontic wires were coated with ZnO nanoparticles using an electrochemical deposition method with three electrodes system in 0.1M Zn(NO3)2. Mechanical properties and frictional resistance of the coated wires were investigated using an universal testing machine. Antibacterial effect of ZnO coating was also investigated. Results: A stable adhered ZnO nanocoating on NiTi wires was obtained. The coated wires have a significant antibacterial activity against S. aureus, S. pyogens and E. coli, and a reduction of frictional forces by 34%. Conclusion: ZnO nanocoating may improve the antibacterial effects of NiTi wires and reduce the frictional resistance. Coating may be implanted in orthodontic practice for faster and safer treatment.

RESUMO Objetivos: Avaliar o efeito do nanorrevestimento de óxido de zinco (ZnO) sobre as propriedades mecânicas e propriedades antibacterianas de fios ortodônticos de NiTi. Métodos: Fios 0,016" x 0,022" de NiTi foram revestidos com nanopartículas de ZnO por meio de um método de deposição eletroquímica com um sistema de três eletrodos a 0,1M Zn(NO3)2. Uma máquina universal de testes foi utilizada para avaliar as propriedades mecânicas e a resistência friccional dos fios revestidos. Além disso, também foram analisadas as propriedades antibacterianas do revestimento de ZnO. Resultados: Obteve-se uma aderência estável das nanopartículas de ZnO sobre os fios NiTi. Os fios revestidos apresentaram atividade antibacteriana significativa contra S. aureus, S. pyogens e E. coli, e apresentaram uma redução de 34% na força de atrito. Conclusão: O revestimento com nanopartículas de óxido de zinco pode melhorar as propriedades antibacterianas e reduzir a resistência friccional dos fios de NiTi. Assim, o revestimento dos fios pode ser utilizado na Ortodontia visando tratamentos mais rápidos e seguros.

Estudo in vitro da influência de diferentes plugs coronários sobre o remanescente da obturação, após preparo para pino, na retenção de pinos metálicos fundidos / In vitro assessment of the influence of different protection plugs over obturation remnant space, after post preparation, on the retention of cast metal posts

Objetivo: Avaliar a influência de diferentes plugs de proteção, acomodados sobre o remanescente da obturação após preparo para pino, na retenção de pinos metálicos fundidos. Métodos: Cinquenta dentes bovinos foram decoronados, manualmente instrumentados até a lima manual Kerr #80 e obturados. A desobturação parcial de 10mm do conduto foi realizada com uma broca Largo e os grupos foram divididos de acordo com os diferentes materiais utilizados como plugs (n=10): Grupo I (Controle, sem plug); Grupo II (plug de Coltosol®); Grupo III (plug, em consistência de massa, de Sealapex® + óxido de zinco); Grupo IV (plug de etil-cianoacrilato); e Grupo V (plug de fosfato de zinco). Uma camada de 1mm de espessura dos diferentes plugs (Grupos II, III, IV ou V) foi acomodada sobre a obturação remanescente. Os espécimes foram selados e armazenados em 100% de umidade, por 7 dias. Após moldagem do conduto, foram confeccionados pinos metálicos fundidos e cimentados com fosfato de zinco. Os espécimes permaneceram em câmara úmida por 45 dias antes do teste de tração, realizado em uma máquina universal de ensaios. Os valores foram expressos em Mega pascal (MPa) e submetidos aos testes ANOVA e Tukey (p<0,05). Resultados: O etilcianoacrilato diminuiu a retenção dos pinos metálicos fundidos (p<0,01). Não houve diferença entre os outros grupos (p>0,05), semelhante- mente ao controle. Conclusão: A proteção da obturação com plugs confeccionados com etil-cianoacrilato prejudica a retenção de pinos metálicos fundidos cimentados com fosfato de zinco, enquanto Sealapex® acrescido de óxido de zinco, fosfato de zinco endurecido ou Coltosol® não interferem na adesividade (AU).

Degradation of Caffeine by Heterogeneous Photocatalysis Using ZnO with Fe and Ag

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.

Impact of calcium aluminate cement with additives on dental pulp-derived cells

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

Propriedades físico-químicas de cimentos endodônticos à base de óxido de zinco e eugenol / Physicochemical properties of zinc oxide and eugenol endodontic cements

Objetivo: Analisar as propriedades físico-químicas, escoamento, tempo de presa, solubilidade e alteração dimensional, dos cimentos endodônticos à base de óxido de zinco e eugenol: Endomethasone N, Endofill e Grosmann, de acordo com a especificação número 57 da American Dental Association. Métodos: Realizou-se os testes nas condições ambientais de 23° ± 2°C e 50 ± 5% de umidade relativa do ar, mantidas 48 h antes dos procedimentos, repetindo-se cinco vezes e obtendo-se uma média aritmética. Resultados: Os cimentos à base de óxido de zinco e eugenol analisados apresentaram tempo de endurecimento elevados, para o teste de escoamento, o Endofill e Grossman apresentaram-se acima do estabelecido. Em relação à solubilidade, o Endomethasone N esteve dentro do padrão e os demais cimentos excederam. Conclusão:Todos os cimentos analisados obtiveram valores diferentes do recomendado para alteração dimensional. Nenhum dos cimentos enquadrou-se completamente nas normatizações.

Aim: To analyze the physical-chemical properties, flow, setting time, solubility and dimensional change of endodontic cements, based on zinc oxide and eugenol: Endomethasone N, Endo fill, and Grosmann, according to specification number 57 of the American Dental Association. Methods: The tests were conducted under environmental conditions of 23° ± 2°C and 50 ± 5% relative air humidity, maintained for 48 h prior to the procedures, repeating five times and obtaining an arithmetic mean. Results: The cements based on zinc oxide and eugenol analyzed in this study showed high hardening times. For the flow test, Endo fill and Grossman were above the established parameters. Regarding solubility, Endomethasone N was within the standard, while the other cements exceeded this standard. Conclusion: All analyzed cements obtained values that proved to be different from those recommended for dimensional changes. None of the cements were completely compliant with the regulations.

Avaliação antimicrobiana in vitro da nanoestrutura de óxido de zinco para posterior aplicação em embalagens / Antimicrobial evaluation in vitro of zinc oxide nanoestruture for subsequent application in packaging

A goiaba é uma das fruticulturas que se destaca no Brasil, por ser rica em nutrientes e ter elevada produção, porém há uma elevada perda/desperdício desse fruto pela sua alta perecibilidade. Logo, o objetivo deste estudo foi avaliar a atividade antimicrobiana das nanoestruturas de ZnO, a fim de aplicá-las em filmes de goma tara para preservação da goiaba. Foi feita a análise da curva de crescimento das bactérias Escherichia coli, Enterobacter cloacae, Salmonella typhimurium e Staphylococcus aureus na presença da nanoestrutura no leitor de microplaca. Estas apresentaram atividade antimicrobiana frente às bactérias, visto que houve o retardo do crescimento com o passar do tempo de análise. Verifica-se o potencial uso desta nanoestrutura para aumentar vida útil da goiaba.

Filme de goma tara com nanoestrutura de ZnO para preservação de fruto pós-colheita / Tare gum film with ZnO nanostructures for preservation of postharvest fruit

O Brasil é o 3º maior produtor mundial de frutas, porém as perdas/desperdícios no pós-colheita podem chegar até 30 %, principalmente, pelo metabolismo do fruto e fitopatógenos. A nanotecnologia surge, então, como alternativa para mitigar esse problema, sendo o setor de embalagens o mais promissor. Assim, o objetivo deste trabalho foi obter e caracterizar de filmes de goma Tara com nanoestruturas de óxido de zinco (ZnO) com atividades antimicrobianas. O filme obteve espessuras entre 0,04957 e 0,36380 mm, sendo o filme com 5% (m/v) de nanoestrutura de ZnO com maior espessura. A porcentagem de solubilidade dos filmes de nanoestruturas de ZnO foi mais elevada que o filme sem nanoestrutura. O teor de umidade variou de 32,5592 a 10,9658 % entre os filmes e à medida que a concentração de nanoestrutura aumentou houve aumento da permeabilidade.

Effect of the incorporation of zinc oxide nanoparticles on the flexural strength of auto- polymerized acrylic resins / Efecto de la incorporación de nanopartículas de óxido de zinc en la resistencia a la flexión de las resinas acrílicas autopolimerizadas

Background: Auto-polymerized acrylic resins are commonly used in many applications in dentistry including in maxillofacial rehabilitation such as interim prostheses, denture repair, reline, orthodontic appliances, record base, among others. These substances, however, have some negative aspects such as poor mechanical properties. Aim: The objective of the current study was to evaluate the effect of incorporating zinc oxide nanoparticles to auto-polymerized acrylic resins on their flexural strength. Materials and methods: Thirty specimens were made from auto-polymerized acrylic resins, divided into three main groups (1 control and 2 experimental). Each group had ten specimens. The two experimental groups comprised the zinc oxide powder at 1% and 2% concentrations, respectively. Acrylic specimens were fabricated with the dimension of 65mm length, 10mm width and 2.5mm thickness according to ISO 1567 specification 1999. Each specimen was subjected to the flexural strength test by a universal testing machine. The crosshead speed for the flexural strength test was 5mm/min until fracture occurred. The SPSS version 16 was utilized for the statistical analysis. The ANOVA and Tukey were used for the comparison among all groups. Results: there was a significant increase (p<0.001) in the flexural strength of the acrylic resins following the addition of zinc oxide particles (control group: 133.27 SD 1.73, ZnO 1%: 154.28 SD 2.90, ZnO 2%: 176.45 SD 0.94). Conclusions: The incorporation of zinc oxide nanoparticles has a significant effect on the flexural strength of auto-polymerized acrylic resins.

Antecedentes: Las resinas acrílicas autopolimerizadas se usan comúnmente en muchas aplicaciones en odontología, incluyendo la rehabilitación maxilofacial, en prótesis provisionales, reparación de prótesis, revestimientos, en aparatos de ortodoncia, bases de registro, entre otros. Estas sustancias, sin embargo, tienen algunos aspectos negativos tales como propiedades mecánicas deficientes. Objetivo: el objetivo del presente estudio fue evaluar el efecto de la incorporación de nanopartículas de óxido de zinc en la resistencia a la flexión de resinas acrílicas autopolimerizadas. Materiales y métodos: Treinta muestras de resinas acrílicas autopolimerizadas fueron hechas, divididas en tres grupos principales (un grupo control y dos experimentales), cada grupo con diez especímenes. Se incorporó polvo de óxido de zinc en los dos grupos experimentales, en concentraciones de 1% y 2%, respectivamente. Las muestras de acrílico se fabricaron con una dimensión de 65mm de longitud, 10mm de ancho y 2,5mm de espesor según la especificación ISO 1567 1999. Cada muestra se sometió a la prueba de resistencia a la flexión mediante una máquina de prueba universal. La velocidad de la cruceta para la prueba de resistencia a la flexión fue de 5mm/min hasta que se produjo la fractura. Se utilizó la versión SPSS 16 para el análisis estadístico. El ANOVA y Tukey se utilizaron para la comparación entre todos los grupos. Resultados: Se observó un aumento significativo (p<0.0 01) en la resistencia a la flexión de las resinas acrílicas luego de la adición de partículas de óxido de zinc (grupo de control: 133,27 SD 1,73 MPa, ZnO 1%: 154,28 SD 2,90 MPa, ZnO 2%: 176,45 SD 0,94 MPa). Conclusiones: La incorporación de nanopartículas de óxido de zinc tiene un efecto significativo en la resistencia a la flexión de las resinas acrílicas autopolimerizadas.

Is treatment with platelet-rich fibrin better than zinc oxide eugenol in cases of established dry socket for controlling pain, reducing inflammation, and improving wound healing?

OBJECTIVES: To appraise the effectiveness of platelet-rich fibrin (PRF) in the management of established dry socket in terms of pain, inflammation, and wound healing. MATERIALS AND METHODS: Two hundred patients with established alveolar osteitis were studied to determine the efficacy of PRF and zinc oxide eugenol (ZOE) for pain control, inflammation reduction, and wound healing. Patients were randomly allocated to Group A (PRF) or Group B (ZOE). Patients were examined on the 1st, 3rd, 7th, and 14th postoperative day and evaluated for pain using visual analogue scale scores, inflammation with a gingival index score, and wound healing through a determination of the number of bony walls exposed. RESULTS: Group A showed better results in terms of pain remission, control of inflammation, and wound healing compared to Group B. Results between groups were statistically significant (P<0.05). CONCLUSION: PRF is a better alternative than ZOE for the effective management of alveolar osteitis.

Synthesis of transdermal aloesin loaded zinc oxide nanoparticles and its inhibitory effect on the activity of tyrosinase / 生物医学工程学杂志

Zinc oxide quantum dots (ZnO QDs) were synthesized by gel-sol method and employed as the transdermal aloesin (Alo) carriers. ZnO QDs were surface-functionalized with amino using aminopropyltriethoxysilane (APTES). Alo was covalently bonded on the surface of ZnO QDs via N,N'-carbonyldiimidazole to obtain Alo NPs, which were characterized by transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analyzer (TGA). TEM images showed that ZnO QDs were analogously sphere and monodisperse with a reasonably narrow size distribution, of which was around 4 nm. The size of Alo NPs increased to around 8 nm due to the surface modification. The intense bands at around 3 400 cm and 1 200 cm in the FTIR spectrum of Alo NPs from the vibration of -OH indicated the linkage of Alo on the surface of ZnO QDs. The results of TGA analysis showed that the mass ratio of ZnO QDs and Alo were 39.27% and 35.14%, respectively. The penetration of Alo NPs was much higher than raw Alo according to the passive penetration experiments with Franz-type diffusion cells instrument using full-thickness cavy skin, which manifested the improvement of the penetration for Alo delivered by ZnO QDs. The pH-controlled drug release behavior was investigated. At pH 7.4, only a small amount of Alo (1.45% ± 0.21%) had been released after 2 h. In contrast, as incubation at pH 5.0 of which pH was similar to endosomal environment, Alo was released very fast (87.63% ± 0.46% in 2 h) from Alo NPs, confirming that Alo NPs could response to the pH and realize the intracellular drug release. The inhibitory effect of Alo NPs on tyrosinase was in a dose dependent manner. When the concentration of Alo NPs was 12.5 μg/mL, the inhibition rate was up to 40.32% ± 1.57%. All the results show that the Alo NPs hold a great potential in transdermal tyrosinase inhibition.

Clinical and Radiographic evaluation of mixture of Zinc Oxide powder and Nanohydroxyapatite as an obturating material in primary molars / Avaliação clínica e radiográfica da associação do pó de óxido de zinco com nanohidroxiapatita como um material obturador utilizado em primeiros molares

Pulpectomy is the treatment alternative in rescuing the pulpally involved carious primary teeth. Various obturating materials are being used to conserve an infected deciduous dentition. The present study documents the use of a novel obturating material in primary molars due to the disadvantages associated with of the currently used materials. Objective: To evaluate clinically and radiographically the success rate of the mixture of zinc oxide powder and nanohydroxyapatite with saline as an obturating material in primary molars and also to compare its efficiency with Endoflas. Material and Methods: Thirty pulpectomy indicated primary molars were randomly divided into two equal groups; Group I (mixture of zinc oxide powder and nanohydroxyapatite with saline) and Group II (Endoflas FS). The teeth were evaluated using various clinical and radiographic criteria at 3, 6 and 9-month intervals. The obtained results were statistically analyzed (P <0.05). Results: The overall present study findings revealed 100% clinical success in both the groups. Whereas radiographically, success reported was 66% for Group I and 100% for Group II at the end of 9 months followup. The difference in the radiographic success rate between the two groups was statistically significant (P <0.05). Conclusion: Endoflas FS had demonstrated high success rate both clinically and radiographically when compared to the novel combination of a mixture of zinc oxide powder and nanohydroxyapatite with saline as obturating material. (AU)

Pulpectomia é uma alternativa de tratamento que visa resgatar polpas envolvidas em processos cariosos de dentes decíduos. Vários materiais obturadores estão sendo usados para conservar a dentição decídua infectada. O presente estudo relata o uso de um novo material obturador em molares decíduos devido às desvantagens dos materiais atualmente utilizados. Objectivo: Avaliar clínica e radiograficamente a taxa de sucesso da mistura de pó de óxido de zinco e nanoidroxiapatita como material obturador em molares decíduos e também comparar sua eficiência com Endoflash. Material e Métodos: Trinta molares decíduos que foram indicados para pulpectomias foram divididos aleatoriamente em dois grupos iguais; Grupo I (mistura de pó de óxido de zinco e nanoidroxiapatita) e Grupo II (Endoflash). Os dentes foram avaliados utilizando vários critérios clínicos e radiográficos em intervalos de 3, 6 e 9 meses. Os resultados obtidos foram analisados estatisticamente (P <0,05). Resultados: Os achados gerais do presente estudo revelaram sucesso clínico de 100% em ambos os grupos. Enquanto que radiograficamente, o sucesso relatado foi de 66% para o Grupo I e 100% para o Grupo II ao final de 9 meses de acompanhamento. A diferença na taxa de sucesso radiográfico entre os dois grupos foi estatisticamente significante (P <0,05). Conclusão: O Endoflas demonstrou alta taxa de sucesso tanto clínica como radiograficamente quando comparado à nova combinação de pó de óxido de zinco e nanoidroxiapatita como material obturador (AU)