358 research outputs found
PET and optical imaging of caveolin-1 in gastric tumors
Previous studies have suggested tumoral caveolin-1 (CAV1) as a predictive biomarker for the response to anti-HER2 antibody drug therapies in gastric tumors. In this study, radiolabeled and fluorescently labeled anti-CAV1 antibodies were developed and tested as an immunoPET or optical imaging agent to detect CAV1 in HER2-positive/CAV1-high NCIN87 gastric tumors. The expression of CAV1 receptors in NCIN87 gastric tumors and nontumor murine organs was determined by Western blot. Binding assays were performed to validate the anti-CAV1 antibody specificity for CAV1-expressing NCIN87 cancer cells. Subcutaneous and orthotopic NCIN87 xenografts were used for PET imaging an
Magnetic carbon composites as recycling electron shuttles on anaerobic biotransformations
Book of Abstracts of CEB Annual Meeting 2017[Excerpt] The unique properties of magnetic nanoparticles (MNP), such as high surface area, magnetic, sorption and catalytic characteristics, make them very versatile for many applications in different areas including environmental remediation, as catalysts, adsorbents, immobilising agents for microorganisms and enzymes, and as supports for biofilm growth and water disinfectants. In order to improve their stability and to introduce additional surface properties and functionalities, MNP can be coated with carbon materials (CM) due to their chemical stability, biocompatibility and possibility of tailoring their textural and surface chemical properties for specific applications [1]. We have previously proved that various CM, including activated carbon, carbon xerogels and carbon nanotubes (CNT), can be used as redox mediators (RM) in anaerobic biotransformation, accelerating the electron transfer and, consequently, the reduction rates of organic compounds [1,2]. The combination of CM with MNP offers the possibility of creating magnetic carbon composites with synergistic properties: the adsorptive and catalytic properties of both and the magnetic character of MNP, improving the material performance and rendering it easier to be retained and recovered, by applying a magnetic field. [...]info:eu-repo/semantics/publishedVersio
Effect of essential oils on the planktonic of S. aureus and E. coli cells
The essential oils of aromatic plants and their components have a wide range of applications in ethno-medicine, preservation, food flavoring and fragrances and in the perfume industries. Some essential oils derived from plants have revealed promising antimicrobial activity against a wide range of bacteria, including antibiotic resistant species.
The aim of this study was to examine the antimicrobial effect of essential oils of Cinnamomum zeylanicum and Cymbopogon martini against planktonic Staphylococcus aureus and Escherichia coli growth.
The antimicrobial activity of the essential oils was checked by bacterial growth, at 37 ºC and 120 rpm, in the presence of increasing concentrations of each essential oil for 24 h. Essential oils were dissolved in DMSO (2.0 %) and saline water (0.85 %) with tween 80 (0.5 %) in order to obtain final concentrations of 0.06 %, 0.09 % and 0.12%, for E. coli, and 0.09 %, 0, 12 %, 0.36 % and 0.48 %, for S. aureus. Bacterial planktonic growth over time was followed by the quantification of the number of viable through cultivation of aliquots in TSA.
Data showed that E. coli was more sensitive to the action of both essential oils, since complete planktonic growth inhibition was attained with a concentration of 0.09 % of the essential oil of C. zeylanicum oil and 0.06 % of the essential oil of C. Martini. Conversely, S. aureus was less sensitive to the antimicrobial action of the essential oils. C. zeylanicum essential oil inhibited S. aureus growth only at concentrations of 0.36 % and 0.48 %, after 4 and 2 hours of growth. However, unexpectedly after 24 hours those S. aureus cells recovered gradually their planktonic growth.
The data pointed out that it is crucial to check the bacterial behavior in the presence of antimicrobial products in different concentrations and over time due to the possible development of bacterial tolerance towards the mechanisms of action of those products. In fact, antimicrobials may have a positive effect in the early hours of application, as demonstrated by some results of this experiment. However, for longer times, the inhibitory effect of antimicrobials can be reverted by bacteria making ineffective their use as disinfectants in food industries. Addiotionally, the continuous exposure of bacteria to antimicrobials can influence the process of microbial resistance de development and increase. These preliminary results demonstrated the possibility of using essential oils of C. zeylanicum and C. martini against two bacteria that are responsible for foodborne illnesses at low concentrations but only for slightly prolonged periods of exposure
Spherical and rod shaped mesoporous nanosilicas for cancer- targeted and photosensitizers delivery in photodynamic therapy
Mesoporous silica nanoparticles (MSNPs) have attracted much attention in many biomedical applications. One of the fields in which smart functional nanosystems have found wide application is cancer treatment. Here, we present new silica nanoparticle-based systems which have been explored as efficient vehicles to transport and deliver photosensitizers (PSs) into tumor tissues during photodynamic therapy (PDT). In this work, we report the preparation, characterization, and in vitro studies of distinct shaped MSNPs grafted with S-glycoside porphyrins (Pors). The ensuing nanomaterials were fully characterized, and their properties as third-generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UM-UC-3, were examined. The best uptake results were obtained for MSNP-PS2, while MSNP-PS1 showed the lowest cellular uptake among the nanocarriers tested, but revealed the best phototoxicity in both cancer cells. Overall, the phototoxicity was higher with MSNPs than with mesoporous silica nanorods (MSNRs) and higher uptake and phototoxicity were consistently observed in UM-UC-3 rather than in HT-1376 cancer cellpublishe
Exopolysaccharide production by the marine bacterium Alteromonas macleodii Mo169 using fruit pulp waste as the sole carbon source
project LA/P/0140/202019 of the Associate Laboratory Institute for Health and Bioeconomy – i4HB.
Publisher Copyright:
© 2023 The Author(s)A sugar-rich apple pulp waste generated from fruit processing for juice production was used as the sole carbon source for the cultivation of Alteromonas macleodii Mo169, a marine bacterium known for its EPS-secreting ability. The strain efficiently utilized the glucose and fructose present in the apple pulp waste, reaching biomass and EPS production of 9.20 ± 0.61 and 3.51 ± 0.08 g L−1, respectively, in 24-hour bioreactor cultivation. Two high molecular weight (Mw) fractions (1.7 ± 0.0 and 0.74 ± 0.0 MDa) were detected in the sample recovered from the cell-free supernatant by dialysis. The compositional analysis revealed the presence of glucose (31.1 ± 0.2 mol%), arabinose (23.9 ± 0.1 mol%), mannose (17.3 ± 0.1 mol%), glucosamine (10.3 ± 0.5 mol%), galactose (8.7 ± 0.0 mol%) and galacturonic acid (8.7 ± 0.0 mol%), as well as a high content in sulphate (6.0 ± 0.5 wt%). Given the presence of a high Mw polysaccharide in the apple pulp waste, probably pectin, a fraction of the detected sugar monomers might be attributed to that polymer, which was recovered together with A. macleodii Mo169 EPS. Concomitant with EPS synthesis, there was a viscosity build-up in the cultivation broth, which developed a shear-thinning fluid behaviour not observed in the initial medium. Therefore, this study demonstrates that apple pulp waste can be efficiently converted into a novel polysaccharide by A. macleodii Mo169 in a sustainable bioprocess. Moreover, the EPS sugar and acyl composition, together with its good thickening capacity, render the biopolymer of interest for use in several applications.publishersversionpublishe
Fisetin derivatives exhibit enhanced anti-inflammatory activity and modulation of endoplasmic reticulum stress
Fisetin (FST) is a dietary flavonol that is known to possess multiple relevant bioactivities, raising the question of its potential health benefits and even its use in novel pharmacological approaches. To attain this prospect, some limitations to this molecule, namely its poor bioavailability and solubility, must be addressed.
Inflammation and endoplasmic reticulum (ER) stress are often hand in hand in the context of chronic disease. Both are activated upon perceived disturbances in homeostasis but can be deleterious when intensely or chronically activated. We have synthesized a set of FST derivatives trying to improve the biological properties of the parent molecule. These new molecules were tested along with the original compound for their ability to mitigate the activation of these signaling pathways.
FST has proven to be effective against the onset of inflammation, reducing NF-κB activation, cytokine release, inflammasome activation and ROS generation, as well as decreasing the activation of the unfolded protein response (UPR). Some of the tested derivatives are also described as new caspase-1 inhibitors, being also capable of reducing pro-inflammatory cytokines and ER stress markers.(undefined
CM@MNP composites for the biodegradation of organic compounds
The ability of different Carbon Materials (CM), including
Activated Carbon, Xerogels and Nanotubes, to accelerate the
chemical and biological reduction rates of dyes and aromatic
amines, and their advantages in comparison with soluble
electron shuttles, such not needing to be constantly dosed, due
to being continuously regenerated in the process, was previously
demonstrated [1-3]. Though, powder CM is tricky to retain inside
continuous reactors due to their low density. The talent of
Magnetic NanoParticles (MNP) as strong reducers also enables
their use in the remediation. In this way, our investigation aims to
combine both materials to create a CM@MNP composite with
synergistic properties by integrating the high catalytic activity and
magnetic character. Combining materials is advantageous to
exploit new applications and minimize cost.FCT Strategic PEst-OE/EQB/LA0023/2013Project “BioEnv - Biotechnology and Bioengineering for a sustainable world”, REF.NORTE-07-0124 FEDER-000048.” Co-funded by the Programa Operacional Regional do Norte (ON.2 – O NovoNorte), QREN, FEDER
Benthic foraminiferal response to variations in temperature, salinity, dissolved oxygen and organic carbon, in the Guanabara Bay, Rio de Janeiro, Brazil
Recent benthic foraminiferal distribution patterns in Guanabara Bay are investigated in relation to temperature, salinity, dissolved oxygen and organic carbon content. Patterns of foraminiferal fauna differ between the entrance of the bay and inner parts. The primary result of the present study is that the distribution of Cassidulina subglobosa and Discorbis williamsoni appear to be governed by lower temperature and higher salinities being found in the entrance of the bay. According to dissolved oxygen content it was observed that Quinqueloculina seminulum occurs when values are higher than 2 mg/l, being intolerant to low oxygen bottom water conditions. By the other hand, Buliminella elegantissima, Bolivina striatula and Bulimmina elongata flourishes under low oxygen waters and in sediment where the organic matter accumulation is high, being found mainly in the central parts of the bay.Padrões de distribuição de foraminíferos bentônicos recentes são investigados com relação a temperatura, salinidade, oxigênio dissolvido e conteúdo de carbono orgânico. A distribuição de foraminíferos é diferente na entrada da baía se comparada às partes internas. Os primeiros resultados mostram que Cassidulina subglobosa e Discorbis williamsoni são encontradas em ambientes com baixa temperatura e altas salinidades na entrada da baía. De acordo com o teor de oxigênio dissolvido foi observado que Quinqueloculina seminulum ocorre quando os valores são mais altos que 2mg/l, sendo intolerante às condições. Por outro lado, Buliminella elegantissima, Bolivina striatula e Bulimmina elongata aparecem nas partes centrais da baía, que são locais com baixa oxigenação e sedimentos onde a acumulação de matéria orgânica é alta
Galactodendritic Phthalocyanine Targets Carbohydrate- Binding Proteins Enhancing Photodynamic Therapy
Photosensitizers (PSs) are of crucial importance in the effectiveness of photodynamic therapy (PDT) for cancer. Due to their
high reactive oxygen species production and strong absorption in the wavelength range between 650 and 850 nm, where
tissue light penetration is rather high, phthalocyanines (Pcs) have been studied as PSs of excellence. In this work, we report
the evaluation of a phthalocyanine surrounded by a carbohydrate shell of sixteen galactose units distributed in a dendritic
manner (PcGal16) as a new and efficient third generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UMUC-
3. Here, we define the role of galacto-dendritic units in promoting the uptake of a Pc through interaction with GLUT1
and galectin-1. The photoactivation of PcGal16 induces cell death by generating oxidative stress. Although PDT with PcGal16
induces an increase on the activity of antioxidant enzymes immediately after PDT, bladder cancer cells are unable to recover
from the PDT-induced damage effects for at least 72 h after treatment. PcGal16 co-localization with galectin-1 and GLUT1
and/or generation of oxidative stress after PcGal16 photoactivation induces changes in the levels of these proteins.
Knockdown of galectin-1 and GLUT1, via small interfering RNA (siRNA), in bladder cancer cells decreases intracellular uptake
and phototoxicity of PcGal16. The results reported herein show PcGal16 as a promising therapeutic agent for the treatment
of bladder cancer, which is the fifth most common type of cancer with the highest rate of recurrence of any cancer
Bioprocessing of recombinant proteins using alternative purification platforms
The advent of biopharmaceuticals in modern medicine brought enormous benefits to diverse human diseases and improved the well-being of many people worldwide. Since the FDA approval of humulin (recombinant insulin) in 19821, remarkable advances in the treatment of chronic diseases have been achieved with biopharmaceutical-based therapies2. This sector represents 40% of ca. 6000 products currently in clinical development2, and is dominated by therapeutic proteins with over 200 protein drugs in the market1. Along the years, many improvements in the biopharmaceuticals upstream stage resulted in high titers of the desired product, and shifted the bioprocess bottleneck to the downstream processing, which is currently dominated by chromatography, accounting with more than 70% of total downstream costs3. Aiming at finding new cost-effective, efficient and sustainable technologies for proteins purification, novel polymer-polymer aqueous biphasic systems (ABS) with ionic liquids (ILs) as adjuvants are investigated as alternative purification platforms for the downstream of interferon alfa 2b (IFNα2b) from Escherichia coli BL21 cultures. Initial experiments showed that the production of IFNα2b is higher using the SOB culture medium and the western-blot analysis revealed that it is present in the inclusion body fraction. This fraction was washed, solubilized using a specific buffer and, finally dialyzed. After analyzing the stability of the target protein in several phase-forming components, the ternary phase diagrams of ABS composed by polyethylene glycol (PEG), polypropylene glycol (PPG) with ILs as adjuvants were determined at 25 °C, as well as the corresponding tie-lines, tie-line lengths and critical points. Chloride-based ILs combined with cholinium, imidazolium, pyrrolidinium, piperidinium, tetralkylammonium and tetralkylphosphonium cations were investigated.
In summary, this study reports effective IFNα2b purification platforms from E. coli based on polymer-polymer-ABS, being highlighted the beneficial role of ILs in the downstream processing of proteins, either as adjuvants in ABS or by exploring new ILs features in protein stabilization.publishe
- …