22 research outputs found

    Polymer Biocompatibility

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    Insight into the development of versatile dentin bonding agents to increase the durability of the bonding interface

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    Despite the huge improvements made in adhesive technology over the past 50 years, there are still some unresolved issues regarding the durability of the adhesive interface. A complete sealing of the interface between the resin and the dentin substrate remains difficult to achieve, and it is doubtful whether an optimal interdiffusion of the adhesive system within the demineralized collagen framework can be produced in a complete and homogeneous way. In fact, it is suggested that hydrolytic degradation, combined with the action of dentin matrix enzymes, destabilizes the tooth-adhesive bond and disrupts the unprotected collagen fibrils. While a sufficient resin–dentin adhesion is usually achieved immediately, bonding efficiency declines over time. Thus, here, a review will be carried out through a bibliographic survey of scientific articles published in the last few years to present strategies that have been proposed to improve and/or develop new adhesive systems that can help prevent degradation at the adhesive interface. It will specially focus on new clinical techniques or new materials with characteristics that contribute to increasing the durability of adhesive restorations and avoiding the recurrent replacement restorative cycle and the consequent increase in damage to the tooth

    Importância do Diagnóstico Precoce de Hipomineralização Molar-incisivo (HMI): Revisão de Literatura / Importance of Early Diagnosis of Molar-Incisor Hypomineralization (HMI): Literature Review

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    Hipomineralização molar-incisivo (HMI) trata-se de uma patologia de origem sistêmica caracterizada pela diminuição da mineralização de um até 4 primeiros molares permanentes e que surge frequentemente associada aos incisivos permanentes, os quais podem estar igualmente afetados. Foi realizada uma busca e discussão da literatura científica nas bases de dados eletrônicas SciencDirect, MEDLINE/PubMed, Periódicos CAPES e Cochrane dos seguintes descritores: Desmineralização do Dente, Hipomineralização molar-incisivo e MHI. Foram selecionados artigos na língua inglesa e portuguesa entre os anos de 2001 e 2020. O presente trabalho reune e discute a literatura científica a respeito da HMI evidenciando a importância do diagnóstico precoce e descrevendo as principais alterações decorrentes da patologia e suas implicações clínicas. Conclui-se que o diagnóstico precoce da patologia pode resultar na diminuição da necessidade de tratamentos mais invasivos e proporcionar ao paciente acometido uma qualidade de vida melhor incluindo alívio de dores, melhora na estética, redução na possibilidade de traumas psicológicos ao paciente. Além disso, o manejo do HMI é desafiador mesmo para os clínicos mais experientes já que necessita de uma avaliação individualizada quanto a severidade, custo do tratamento, sintomatologia e idade do paciente

    Comprehensive multivariate correlations between climatic effect, metabolite-profile, antioxidant capacity and antibacterial activity of Brazilian red propolis metabolites during seasonal study

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    The standardization of apiceutical products like as propolis extracts has been widely debated worldwide and variations in the propolis chemical composition are still very relevant topics for use-standardized of different propolis-type as medication by much of the world’s population. The present manuscript discuss important issues related to the climate effect and variations in propolis metabolite-profiling changes, antioxidant capacity and variations of the antibacterial activity of the Brazilian red propolis metabolites using comprehensive multivariate correlations. It was observed the increasing of guttiferones concentrations during the intense drought period and drastic decreasing in rainy period. The climate variation induced the high concentration of flavonoids in rainy period with pronounced dropped in some rainy months. The Pearson´s analysis demonstrated correlation between IC50 from DPPH and guttiferones and flavonoids concentrations. The PCA-X and Hotelling T2 test showed outliers during the months with lowest concentrations of formononetin and isoliquiritigenin was observed in antibacterial tests. The PLS-DA, OPLS-DA and VIP analysis demonstrate guttiferone E, guttiferone B, liquiritigenin, naringenin are considered important substances responsible by anti-staphylococcal activity in red propolis composition during the rainy season and drought period, but a synergistic effect with other flavonoids and isoflavonoids are not ruled out

    Polymeric nanoparticles of Brazilian red propolis extract : preparation, characterization, antioxidant and leishmanicidal activity

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    The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of "multiple-constituent extract in co-delivery system" for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200–280 nm) in nanometric scale and zeta analysis (−20 to −26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 μg/mL and 31.3 μg/mL, 47.2 μg/mL, 154.2μg/mL and 193.2 μg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on Leishmania (V.) braziliensis. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis

    ALIMENTOS, NUTRACÊUTICOS E PLANTAS MEDICINAIS UTILIZADOS COMO PRÁTICA COMPLEMENTAR NO ENFRENTAMENTO DOS SINTOMAS DO CORONAVÍRUS (COVID-19): UMA REVISÃO

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    The present prospective work of scientific articles related to foods and natural products with anti-Covid activity in databases in order to present a scientific community, to governments and society as main foods, nutraceuticals and medicinal plants as strategies used by countries during the COVID-19 pandemic. A review of articles on food, medicinal plants and biotechnology was carried out in databases of scientific articles such as: CAPES journals, PubMed, Elsevier's Science Direct, Willey on library library, Taylor & Francis Springer-Nature database, BMC, Hindawi, Scielo, ACS - American Chemical Society, Google Scholar, in addition to the Patent Database “The LENS” and “Questel-Orbit”. Foods used in daily life such as garlic, ginger, turmeric, sour orange, vegetables, lactobacilli demonstrate proven anti-virus action. Medicinal plants used by Traditional Chinese, Korean and Indian Medicine also demonstrate anti-Covid activity and used during the coronavirus outbreak. Some medicinal plants, green propolis extract, red propolis extract, royal gelly, polen, honey have also been cited as anti-covid, natural anti-inflammatory and immunomodulatory products.O presente trabalho prospectou artigos científicos relacionadas à alimentos e produtos naturais com atividade anti-Covid com o intuito de apresentar, à comunidade científica, aos governos e à sociedade, dados sobre as principais estratégias nutracêuticas, biotecnológicas e plantas medicinais utilizadas em alguns países durante o enfrentamento da pandemia COVID-19. A revisão de artigos sobre alimentos, plantas medicinais e produtos biotecnológicos foi realizada nas bases de dados periódicos da CAPES, PubMed, Science Direct, Willey on line library, Springer-Nature, Taylor & Francis, BMC, Hindawi, Scielo, ACS – American Chemical Society, Google acadêmico, “The LENS” e Questel-Orbit. Alimentos de uso frequente como alho, gengibre, cúrcuma, laranja azeda, vegetais e lactobacilos demonstraram ação anti-coronavirus comprovada. Foram descritos usos de plantas medicinais da Medicina tradicional Chinesa, Coreana, Indiana bastante utilizadas durante a pandemia. Algumas plantas medicinais e nutracêuticos como: extrato de própolis verde e extrato de própolis vermelha brasileiras, geleia real, pólen e mel também foram citados como produtos anti-covid, antiinflamatórios naturais e imunomodulatórios

    Avaliação em curto e médio prazo da sorção e da solubilidade de resinas compostas à base de metacrilato e de silorano em saliva artificial

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    INTRODUÇÃO: A absorção/adsorção de moléculas de água por monômeros hidrofílicos dentro de materiais resinosos expostos à umidade da boca pode resultar em degradação. OBJETIVO: Este estudo avaliou sorção e solubilidade de resinas compostas à base de metacrilato e silorano em contato com saliva artificial, nos períodos de um dia (curto prazo), e 30 e 90 dias (médio prazo). MATERIAL E MÉTODO: Sessenta corpos de prova foram confeccionados com as resinas Filtek® Z250 e Filtek® P90 Silorano (3M/ESPE), e depois imersos em saliva artificial a 37 ± 1 ºC durante um, 30 e 90 dias. Os dados foram analisados usando-se ANOVA um fator/dois fatores seguido dos testes Tukey ou Tamhane (α = 0,05). RESULTADO: As médias de sorção das duas resinas aumentaram com o tempo (p = 0,001). A sorção de Z250 (1 e 90 d) foi significativamente maior do que de P90 (p = 0,008), com valores semelhantes após 30 dias. A solubilidade das resinas também aumentou com o tempo, com diferença significativa entre todos os períodos (p = 0,001), exceto para a resina P90 (entre 1 e 30 d). Não houve diferença estatística significante entre os grupos Z250 (1 d) e P90 (1 dia), Z250 (1 d) e P90 (30 d), e Z250 (30 d) e P90 (90 d). Para os demais pares, comprovaram-se diferenças significativas (p < 0,001). CONCLUSÃO: As propriedades de sorção e solubilidade das resinas compostas testadas foram influenciadas pelo tempo de exposição à saliva artificial. O silorano teve desempenho ora melhor ora semelhante à resina de metacrilato
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