113 research outputs found
New record and distribution extension of Hypsiboas crepitans (Wied-Neuwied, 1824) (Anura, Hylidae) to the northern part of the state of PiauÃ, Brazil
Relatamos o aumento da extensão da distribuição geográfica de Hypsiboas crepitans (Amphibia, Anura) na região do Delta do Rio ParnaÃba, no municÃpio de ParnaÃba, Estado do PiauÃ, nordestedo Brasil. Dois indivÃduos adultos, apresentando comprimento rostro-cloacal (CRC) de 51,2mm e 47,6mm, foram coletados em uma área úmida nas proximidades do Rio Igaraçu (2°53'54 .80 "S e 41°45'30 0,97" W), ampliando a distribuição conhecida deH. crepitans 450 km a norte
Immobilization of biomolecules on natural clay minerals for medical applications
Biomolecules are a group of organic entities that are important in many areas of research on nanomaterials and for biomedical and pharmaceutical applications. Advanced systems have been developed to attempt to protect the activity of biomolecules from rapid degradation and instability. Among these techniques, the incorporation or immobilization of biomolecules has become popular in the development of biocomposites. As such, clay minerals appear to be promising materials; combining a nanometer-scale size with their adsorptive capacity, lack of toxicity, and biocompatibility would result in enhanced biomaterial properties. This mini?review discusses the recent advances concerning biological molecules immobilized on clay minerals and their biomedical applications as biosensors, in regenerative medicine, and even as controlled delivery systems
Phylloseptin-1 is leishmanicidal for amastigotes of Leishmania amazonensis inside infected macrophages
Leishmania protozoans are the causal agents of neglected diseases that represent an
important public health issue worldwide. The growing occurrence of drug-resistant strains of
Leishmania and severe side effects of available treatments represent an important challenge for the
leishmaniases treatment. We have previously reported the leishmanicidal activity of phylloseptin-1
(PSN-1), a peptide found in the skin secretion of Phyllomedusa azurea (=Pithecopus azureus),
against Leishmania amazonensis promastigotes. However, its impact on the amastigote form of
L. amazonensis and its impact on infected macrophages are unknown. In this work, we evaluated the
effects of PSN-1 on amastigotes of L. amazonensis inside macrophages infected in vitro. We assessed
the production of hydrogen peroxide and nitric oxide, as well as the levels of inflammatory and
immunomodulatory markers (TGF-β, TNF-α and IL-12), in infected and non-infected macrophages
treated with PSN-1. Treatment with PSN-1 decreased the number of infected cells and the number
of ingested amastigotes per cell when compared with the untreated cells. At 32 µM (64 µg/mL),
PSN-1 reduced hydrogen peroxide levels in both infected and uninfected macrophages, whereas it
had little effect on NO production or TGF-β release. The effect of PSN-1 on IL-12 and TNF-α secretion
depended on its concentration, but, in general, their levels tended to increase as PSN-1 concentration
increased. Further in vitro and in vivo studies are needed to clarify the mechanisms of action of
PSN-1 and its interaction with the immune system aiming to develop pharmacological applications
Antiviral activity of Intragenic Antimicrobial Peptides (IAPs)
SARS-CoV-2 é um vÃrus zoonótico que está causando enormes danos à saúde pública e à economia mundial. No momento em que o surto de Covid-19 foi declarado, não havia medicamentos antivirais especÃficos disponÃveis e as drogas mais promissoras foram desenvolvidas originalmente para outros propósitos, como a hidroxicloroquina. Vários pesquisadores propõem o desenvolvimento de agentes antivirais de ação ampla como uma primeira frente de combate a vÃrus emergentes, e peptÃdeos são
bons candidatos devido à amplitude de seus alvos moleculares, especificidade de suas interações e baixa toxicidade [1]. Já foram descritos peptÃdeos com atividade desestabilizadora de partÃculas virais, inibidores do processo de internalização viral por meio da interferência com proteÃnas fusionais, peptÃdeos ligantes a glicoproteÃnas virais e com propriedades imunomodulatórias
Acetylated cashew gum-based nanoparticles for the incorporation of alkaloid epiisopiloturine
The natural alkaloid epiisopiloturine has recently become the focus of study for various medicinal properties, particularly for its anti-inflammatory and antischistosomal effect. The incorporation of active molecules in natural polymeric matrices has garnered increasing interest during recent decades. A new derivative of cashew gum successfully obtained by gum acetylation has shown great potential as a carrier in controlled drug release systems. In this work, epiisopiloturine was encapsulated in acetylated cashew gum nanoparticles in order to increase solubility and allow slow release, whereas the morphology results were supported by computer simulations. The particles were produced under a variety of conditions, and thoroughly characterized using light scattering and microscopic techniques. The particles were spherical and highly stable in solution, and showed drug incorporation at high levels, up to 55% efficiency. Using a dialysis-based in vitro assay, these particles were shown to release the drug via a Fickian diffusion mechanism, leading to gradual drug release over approximately 6 h. These nanoparticles show potential for the use as drug delivery system, while studies on their potential anti-inflammatory action, as well as toxicity and efficacy assays would need to be performed in the future to confirm their suitability as drug delivery candidates.This work was conducted in partnership with the Polymer Laboratory of the Federal University of Ceará for polymer modification. The authors thanks Foundation for Science and Technology (FCT) for the fellowships SFRH/BD/97995/2013 (AP) and SFRH/BD/95983/2013 (MPA), in the context of the POCH program. The work at UCIBIO/REQUIMTE was supported by FCT through project UID/MULTI/04378/2013 – POCI/01/0145/FEDER/007728 with financial support from FCT/MCTES through national funds and co-financed by FEDER, under the Partnership Agreement PT2020. The work at REQUIMTE/LAQV received financial support from the European Union (FEDER funds through COMPETE) and National Funds (FCT) through project UID/QUI/50006/2013. The computational time was provided by GRID-Unesp, SICC/IFSP and CENAPAD/SP. The authors also acknowledge CNPq and CAPES for a scholarship and financial aid.info:eu-repo/semantics/publishedVersio
Identification of Eschweilenol C in derivative of Terminalia fagifolia Mart. and green synthesis of bioactive and biocompatible silver nanoparticles
A green synthetic route was developed to prepare silver nanoparticles (AgNPs) in aqueous solution for biological applications. Eschweilenol C, a compound derivative ellagic acid was identified as the main constituent of the aqueous fraction of the ethanolic extract of Terminalia fagifolia Mart. by NMR analysis. In the green synthesis, the ethanolic extract of T. fagifolia and its aqueous fraction were used to promote silver reduction and nanoparticle stabilization. The synthesized AgNPs presented a spherical or polygonal morphology shape by TEM analysis and AgNPs showed high levels of antioxidant and considerable antibacterial and antifungal activities. Synthesized nanoparticles presented significant antioxidant activity by sequestration of DPPH and ABTS radicals, in addition to iron reduction (FRAP assay) and measurement of antioxidant capacity in ORAC units, in addition, AgNP synthesized with the aqueous fraction also demonstrated antioxidant potential in microglial cells. Gram-positive and Gram-negative bacteria were susceptible to growth inhibition by the nanoparticles, among which the AgNPs formed by the ethanolic extract was the most effective. The data obtained by AFM images suggested that AgNPs could lead to the lysis of bacteria and subsequent death. The antifungal assays showed high efficiency against yeasts and dermatophytes. This work represents the first description of antifungal activity by AgNPs against Fonsecaea pedrosoi, the etiologic agent of chromoblastomycosis. In relation to biocompatibility, the AgNPs induced lower haemolysis than AgNO3.We thank Herbert Kogler and Reinhard Wimmer for the identification of Eschweilenol C. The NMR laboratory at Aalborg University is supported by the Obel Family, SparNord and Carlsberg foundations.The authors are grateful to Carla Eiras (LIMAV/CT/UFPI) and to FCT and EU for financial support through project UID/QUI/50006/2013– POCI-01-0145-FEDER-007265 from COMPETE and projectNORTE-01-0145-FEDER-000011 from COMPETE. Thanks to Andreia Pinto for help with the TEM measurements at Instituto de Medicina Molecular (IMM). This work was supported by the Histology and Comparative Pathology Laboratory of the IMMinfo:eu-repo/semantics/publishedVersio
Copper nanoparticles stabilized with cashew gum: Antimicrobial activity and cytotoxicity against 4T1 mouse mammary tumor cell line
Copper nanoparticles stabilized with cashew (CG-CuNPs) were synthesized by reduction reaction using ascorbic acid and sodium borohydride, using the cashew gum (CG) as a natural polymer stabilizer. Dynamic light scattering, atomic force microscopy, Fourier-transform infrared spectroscopy, UV-Vis spectrophotometry, and x-ray diffraction were used to characterize the nanoparticles (CG-CuNPs), and copper was quantified by electrochemical measurement. The UV-vis spectra of the CG-CuNPs confirmed the formation of nanoparticles by appearance of a surface plasmon band at 580 nm after 24 h of reaction. The Fourier-transform infrared spectrum of CG-CuNPs showed the peak at 1704 cm−1 from cashew gum, confirming the presence of the gum in the nanoparticles. The average size of CG-CuNPs by dynamic light scattering and atomic force microscopy was around 10 nm, indicating small, approximately spherical particles. Antimicrobial assays showed that CG-CuNPs had activity against Staphylococcus aureus ATCC 29213 with a minimal inhibitory concentration of 0.64 mM. The cytotoxicity assay on BALB/c murine macrophages showed lower cytotoxic effects for CG-CuNPs than CuSO4·5H2O. Viability cell assays for CG-CuNPs at (0.250 mM) inhibited by 70% the growth of 4T1 LUC (4T1 mouse mammary tumor cell line) and NIH 3T3 cells (murine fibroblast cells) over a 24-h period. Therefore, CG-CuNPs can be used as an antimicrobial agent with lower cytotoxic effects than the CuSO4·5H2O precursor.The author would like to thank at UCM for performingDPV, USP by X-ray diffraction experiment, REQUIMTE/LAQV for FTIR, UnB and UFPI for the cytotoxicityassays, as well as at UFPI for help with DLS, UV-Vis,AFM, and microbiological experiments. This work was supported by Project 400398/2014-1—Desenvolvimento de NanopartÃculas Estabilizadas com Goma de Cajueiro para Aplicações Biotecnologicas, financed by CNPq. AlexandraPlácido is grateful to FCT by her grant SFRH/BD/97995/2013, financed by POPH-QREN-Tipologia 4.1-Formação Avançada, subsidized by Fundo Social Europeu and Ministério da Ciência, Tecnologia e Ensino Superior.info:eu-repo/semantics/publishedVersio
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