1,054 research outputs found

    Nanogold-based materials in medicine: from their origins to their future.

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    The properties of gold-based materials have been explored for centuries in several research fields, including medicine. Multiple published production methods for gold nanoparticles (AuNPs) have shown that the physicochemical and optical properties of AuNPs depend on the production method used. These different AuNP properties have allowed exploration of their usefulness in countless distinct biomedical applications over the last few years. Here we present an extensive overview of the most commonly used AuNP production methods, the resulting distinct properties of the AuNPs and the potential application of these AuNPs in diagnostic and therapeutic approaches in biomedicine

    The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment.

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    Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, the effectiveness of PTT can be improved by combining near infrared (NIR) irradiation with gold nanoparticles (AuNPs) as photothermal enhancers. Herein, an alternative synthetic method using rosmarinic acid (RA) for synthesizing AuNPs is reported. The RA concentration was varied and its impact on the AuNPs physicochemical and optical features was assessed. Results showed that RA concentration plays an active role on AuNPs features, allowing the optimization of mean size and maximum absorbance peak. Moreover, the synthetic method explored here allowed us to obtain negatively charged AuNPs with sizes favoring the local particle accumulation at tumor site and maximum absorbance peaks within the NIR region. In addition, AuNPs were safe both in vitro and in vivo. In conclusion, the synthesized AuNPs present favorable properties to be applied as part of a PTT system combining AuNPs with a NIR laser for the treatment of breast cancer

    O Valor Prognóstico do Ponto Ótimo Cardiorrespiratório após Prova de Esforço Cardiorrespiratória Submáxima na Insuficiência Cardíaca

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    Introduction: Peak oxygen consumption (pVO2) is a key parameter for assessing the prognosis of heart failure with reduced ejection fraction (HFrEF). However, it is less reliable when the cardiopulmonary exercise test (CPET) is not maximal. Objective: To compare the prognostic power of various exercise parameters in submaximal CPET. Methods: Adult patients with HFrEF undergoing CPET in a tertiary center were prospectively assessed. Submaximal CPET was defined as a respiratory exchange ratio ≤1.10. Patients were followed for one year for the primary endpoint of cardiac death and urgent heart transplantation (HT). Various CPET parameters were analyzed as potential predictors of the combined endpoint and their prognostic power (area under the curve [AUC]) was compared using the Hanley-McNeil test. Results: CPET was performed in 442 HFrEF patients (mean age 56±12 years, 80% male), of whom 290 (66%) had a submaximal CPET. Seventeen patients (6%) reached the primary endpoint. The cardiorespiratory optimal point (COP) had the highest AUC value (0.989, p<0.001), and significantly higher prognostic power than other tested parameters, with pVO2 presenting an AUC of 0.753 (p=0.001). COP ≥36 had significantly lower survival free of HT during follow-up (p<0.001) and presented a sensitivity of 100% and a specificity of 89% for the primary endpoint. Conclusion: COP had the highest prognostic power of all parameters analyzed in a submaximal CPET. This parameter can help stratify HFrEF patients who are physiologically unable to reach a maximal level of exercise.info:eu-repo/semantics/publishedVersio

    New Nile blue derivatives as NIR fluorescent probes and antifungal agents

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    The synthesis of four new Nile Blue derivatives with hydrogen, propyl and/or aminopropyl groups as substituents of the amines of 5- and 9-positions is described. Photophysical properties were evaluated in acidified ethanol and aqueous solution at physiological pH. Antifungal activity is also studied through the obtention of MIC values.Thanks are due to Fundação para a Ciência e Tecnologia (FCT) and FEDER (European Fund for Regional Development)-COMPETE-QRENEU for financial support through the Chemistry Research Centre of the University of Minho (Ref. UID/QUI/00686/2013 and UID/QUI/0686/2016), CBMA (PEst OE/BIA/UI4050/2014) and a PhD grant to J.C.F. (SFRH/BD/133207/2017). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC)

    Development and characterization of b-carotene microcapsules composed of starch and protein extract from Amaranth

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    The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid multifunctionalityStudies that have explored the use of biopolymers of Amaranth as encapsulating materials for bioactive compounds1,2,3 demonstrate that it is possible to isolate and encapsulate bioactive compounds with Amaranth biopolymers. Therefore, the added value of Amaranth can be increased, evidenced and studied through the extraction of its compounds and the formation of microcapsules. The objective of this study was the evaluation of the ability of Amaranth biopolymers to microencapsulate a bioactive compound - -carotene. The microencapsulation was performed by spray drying4, and -carotene was added to the Amaranth (Amaranthus cruentus) starch or protein through a solution prepared at the ratio of 1:10 (polymer:-carotene) in corn oil (1 %). The microcapsules were characterized by mean diameter (volume%), particle size distribution, microcapsules morphology by epifluorescence microscopy, microstructure by scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FT-IR) and by measuring encapsulation efficiency. Microcapsules exhibited an average size of 2.22 ± 1.84 m and 1.55 ± 1.12 m for microcapsules composed of Amaranth protein and Amaranth starch, respectively. The microscopy images of both microcapsules showed good sphericity and presence of fluorescence, which indicates good encapsulation capacity of -carotene. FT-IR results showed no differences between spectra of all samples, which indicates that there was no chemical bonding between the capsules and -carotene, but rather an entrapment of -carotene into starch and protein microparticles. The encapsulation efficiency was 71.29 % and 69.32 % for Amaranth starch and protein microcapsules, respectively. Therefore, it can be concluded that the biopolymers extracted from Amaranth can be considered good encapsulating agents for bioactive compounds, thus valorising their use in food formulations.This study was funded by the CNPQ-Brazil; FCT – Portugal (SFRH/BPD/89992/2012, SFRH/BPD/101181/2014, SFRH/BPD/104712/2014 and IF/00300/2015 fellowships); Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER- 027462); Project UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER- 006684) and Project CICECO-Aveiro Institute of Materials POCI-01-0145-FEDER-007679 (FCT UID/CTM/50011/2013).info:eu-repo/semantics/publishedVersio

    Novel benzo[α]phenoxazinium chlorides functionalized with sulfonamide groups as NIR fluorescent probes for vacuole, endoplasmic reticulum, and plasma membrane staining

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    The demand for new fluorophores for different biological target imaging is increasing. Benzo[a]phenoxazine derivatives are fluorochromophores that show promising optical properties for bioimaging, namely fluorescent emission at the NIR of the visible region, where biological samples have minimal fluorescence emission. In this study, six new benzo[a]phenoxazinium chlorides possessing sulfonamide groups at 5-amino-positions were synthesized and their optical and biological properties were tested. Compared with previous probes evaluated using fluorescence microscopy, using different S. cerevisiae strains, these probes, with sulfonamide groups, stained the vacuole membrane and/or the perinuclear membrane of the endoplasmic reticulum with great specificity, with some fluorochromophores capable of even staining the plasma membrane. Thus, the addition of a sulfonamide group to the benzo[a]phenoxazinium core increases their specificity and attributes for the fluorescent labeling of cell applications and fractions, highlighting them as quite valid alternatives to commercially available dyes.FCT (Fundação para a Ciência e Tecnologia, Portugal) and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centers CQ/UM (UID/QUI/00686/2021), and CBMA (Ref. UIDB/04050/2020), as well as a PhD grant to J. C. Ferreira (SFRH/BD/133207/2017 and COVID/BD/151978/2021). The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER

    A chromatographic network for the purification of detergent-solubilized six-transmembrane epithelial antigen of the prostate 1 from Komagataella pastoris mini-bioreactor lysates

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    Funding Information: The authors acknowledge the support from FEDER funds through the POCI-COMPETE 2020–Operational Programme Competitiveness and Internationalisation in Axis I–Strengthening Research, Technological Development and Innovation (Project POCI-01-0145-FEDER-007491), Jorge Barroca-Ferreira's and Ana M. Gonçalves's individual PhD Fellowships (SFRH/BD/130068/2017 and SFRH/BD/147519/2019, respectively), and Luís A. Passarinha's sabbatical fellowship (SFRH/BSAB/150376/2019) from FCT–Fundação para a Ciência e Tecnologia. This work was also supported by the Health Sciences Research Centre CICS-UBI (UIDB/00709/2020 and UIDP/00709/2020), the Applied Molecular Biosciences Unit UCIBIO (UIDB/04378/2020 and UIDP/04378/2020) and the Associate Laboratory Institute for Health and Bioeconomy–i4HB (project LA/P/0140/2020) which are financed by National Funds from FCT/MCTES. Publisher Copyright: © 2022The Six-Transmembrane Epithelial Antigen of the Prostate 1 (STEAP1) is an integral membrane protein involved in cellular communications, in the stimulation of cell proliferation by increasing Reactive Oxygen Species levels, and in the transmembrane-electron transport and reduction of extracellular metal-ion complexes. The STEAP1 is particularly over-expressed in prostate cancer, in contrast with non-tumoral tissues and vital organs, contributing to tumor progression and aggressiveness. However, the current understanding of STEAP1 lacks experimental data on the respective molecular mechanisms, structural determinants, and chemical modifications. This scenario highlights the relevance of exploring the biosynthesis of STEAP1 and its purification for further bio-interaction and structural characterization studies. In this work, recombinant hexahistidine-tagged human STEAP1 (rhSTEAP1-His6) was expressed in Komagataella pastoris (K. pastoris) mini-bioreactor methanol-induced cultures and successfully solubilized with Nonidet P-40 (NP-40) and n-Decyl-β-D-Maltopyranoside (DM) detergents. The fraction capacity of Phenyl-, Butyl-, and Octyl-Sepharose hydrophobic matrices were evaluated by manipulating the ionic strength of binding and elution steps. Alternatively, immobilized metal affinity chromatography packed with nickel or cobalt were also studied in the isolation of rhSTEAP1-His6 from lysate extracts. Overall, the Phenyl-Sepharose and Nickel-based resins provided the desired selectivity for rhSTEAP1-His6 capture from NP-40 and DM detergent-solubilized K. pastoris extracts, respectively. After a polishing step using the anion-exchanger Q-Sepharose, a highly pure, fully solubilized, and immunoreactive 35 kDa rhSTEAP1-His6 fraction was obtained. Altogether, the established reproducible strategy for the purification of rhSTEAP1-His6 paves the way to gather additional insights on structural, thermal, and environmental stability characterization significantly contributing for the elucidation of the functional role and oncogenic behavior of the STEAP1 in prostate cancer microenvironment.publishersversionpublishe
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