Standard cancer therapies sometimes fail to deliver chemotherapeutic drugs to tumor cells in a safe and effective manner.
Nanotechnology takes the lead in providing new therapeutic options for cancer ...due to major potential for selective targeting and controlled drug release. Antibodies and antibody fragments are attracting much attention as a source of targeting ligands to bind specific receptors that are overexpressed on cancer cells.
Therefore, researchers are devoting time and effort to develop targeting strategies based on nanoparticles functionalized with antibodies, which hold great promise to enhance therapeutic efficacy and circumvent severe side effects.
Several methods have been described to immobilize antibodies on the surface of nanoparticles. However, selecting the most appropriate for each application is challenging but also imperative to preserve antigen binding ability and yield stable antibody-conjugated nanoparticles.
From this perspective, we aim to provide considerable knowledge on the most widely used methods of functionalization that can be helpful for decision-making and design of conjugation protocols as well. This review summarizes adsorption, covalent conjugation (carbodiimide, maleimide and “click” chemistries) and biotin-avidin interaction, while discussing the advantages, limitations and relevant therapeutic approaches currently under investigation.
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•Tumor targeting is promising to address some drawbacks of conventional chemotherapy.•Antibody-conjugated nanoparticles favor a safe and effective drug delivery to tumor.•Immobilization of antibodies should be well-oriented and keep biological activity.•Functionalization of nanoparticles includes covalent and non-covalent methods.•The ideal conjugation method allows a site-specific reaction and a stable coupling.
► Nannochloropsis sp. was studied as a biorefinery context. ► Production of fatty acids for biodiesel, high added-value compounds and biohydrogen. ► Extracts fractionation by SFE (oils for biodiesel ...and pigments for food). ► Fermentation of biomass leftover by E. aerogenes yielded maximum 60.6mLH2/gdry biomass alga. ► Best SFE conditions extracted 45glipids/100gdry biomass (40°C, 300bar, CO2+ethanol).
The microalga Nannochloropsis sp. was used in this study, in a biorefinery context, as biomass feedstock for the production of fatty acids for biodiesel, biohydrogen and high added-value compounds. The microalgal biomass, which has a high lipid and pigment content (mainly carotenoids), was submitted to supercritical CO2 extraction. The temperature, pressure and solvent flow-rate were evaluated to check their effect on the extraction yield. The best operational conditions to extract 33glipids/100gdrybiomass were found to be at 40°C, 300bar and a CO2 flow-rate of 0.62g/min. The effect of adding a co-solvent (ethanol) was also studied. When supercritical CO2 doped with 20% (w/w) ethanol was used, it was possible to extract 45glipids/100gdrybiomass of lipids and recover 70% of the pigments. Furthermore, the remaining biomass after extraction was effectively used as feedstock to produce biohydrogen through dark fermentation by Enterobacter aerogenes resulting in a hydrogen production yield of 60.6mL/gdrybiomass.
Epigenetic mechanisms have been found to play important roles in environmental stress response and regulation. These can, theoretically, be transmitted to future unexposed generations, yet few ...studies have shown persisting stress-induced transgenerational effects, particularly in invertebrates. Here, we focus on the aquatic microcrustacean Daphnia, a parthenogenetic model species, and its response to salinity stress. Salinity is a serious threat to freshwater ecosystems and a relevant form of environmental perturbation affecting freshwater ecosystems. We exposed one generation of D. magna to high levels of salinity (F0) and found that the exposure provoked specific methylation patterns that were transferred to the three consequent nonexposed generations (F1, F2, and F3). This was the case for the hypomethylation of six protein-coding genes with important roles in the organisms’ response to environmental change: DNA damage repair, cytoskeleton organization, and protein synthesis. This suggests that epigenetic changes in Daphnia are particularly targeted to genes involved in coping with general cellular stress responses. Our results highlight that epigenetic marks are affected by environmental stressors and can be transferred to subsequent unexposed generations. Epigenetic marks could therefore prove to be useful indicators of past or historic pollution in this parthenogenetic model system. Furthermore, no life history costs seem to be associated with the maintenance of hypomethylation across unexposed generations in Daphnia following a single stress exposure.
Abstract The detection, isolation and sorting of cells holds an important role in cell therapy and regenerative medicine. Also, injectable systems have been explored for tissue regeneration in vivo, ...because it allows repairing complex shaped tissue defects through minimally invasive surgical procedures. Here we report the development of chitosan microparticles with a size of 115.8 μm able to capture and expand a specific cell type that can also be regarded as an injectable biomaterial. Monoclonal antibodies against cell surface antigens specific to endothelial cells and stem cells were immobilized on the surface of the microparticles. Experimental results showed that particles bioconjugated with specific antibodies provide suitable surfaces to capture a target cell type and subsequent expansion of the captured cells. Primarily designed for an application in tissue engineering, three main challenges are accomplished with the herein presented microparticles: separation, scale-up expansion of specific cell type and successful use as an injectable system to form small tissue constructs in situ.
Dietary fiber intake, especially viscous soluble fiber, has been established as a means to reduce cardiometabolic risk factors. Whether this is true for blood pressure remains controversial. A ...systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to investigate the effects of viscous soluble fiber supplementation on blood pressure and quantify the effect of individual fibers.
MEDLINE, Embase, and Cochrane databases were searched. We included RCTs of ≥4-weeks in duration assessing viscous fiber supplementation from five types: β-glucan from oats and barley, guar gum, konjac, pectin and psyllium, on systolic blood pressure (SBP) and diastolic blood pressure (DBP). Study data were pooled using the generic inverse variance method with random effects models and expressed as mean differences (MD) with 95% confidence intervals (CIs). Twenty-two (N = 1430) and twenty-one RCTs (N = 1343) were included in the final analysis for SBP and DBP, respectively. Viscous fiber reduced SBP (MD = −1.59 mmHg 95% CI: −2.72,−0.46) and DBP (MD = −0.39 mmHg 95% CI: −0.76,−0.01) at a median dose of 8.7 g/day (1.45–30 g/day) over a median follow-up of 7-weeks. Substantial heterogeneity in SBP (I2 = 72%, P < 0.01) and DBP (I2 = 67%, P < 0.01) analysis occurred. Within the five fiber types, SBP reductions were observed only for supplementation using psyllium fiber (MD = −2.39 mmHg 95% CI: −4.62,−0.17).
Viscous soluble fiber has an overall lowering effect on SBP and DBP. Inclusion of viscous fiber to habitual diets may have additional value in reducing CVD risk via improvement in blood pressure.
ClinicalTrials.gov identifier-NCT02670967.
•Viscous soluble fiber consumption was found to reduce overall SBP and DBP in all populations.•Within individual fiber types, psyllium fiber was found to reduce overall SBP.•Greater reductions in SBP and DBP were found in hypertensive subjects.
Finding robust brain substrates of mood disorders is an important target for research. The degree to which major depression (MDD) and bipolar disorder (BD) are associated with common and/or distinct ...patterns of volumetric changes is nevertheless unclear. Furthermore, the extant literature is heterogeneous with respect to the nature of these changes. We report a meta-analysis of voxel-based morphometry (VBM) studies in MDD and BD. We identified studies published up to January 2015 that compared grey matter in MDD (50 data sets including 4101 individuals) and BD (36 data sets including 2407 individuals) using whole-brain VBM. We used statistical maps from the studies included where available and reported peak coordinates otherwise. Group comparisons and conjunction analyses identified regions in which the disorders showed common and distinct patterns of volumetric alteration. Both disorders were associated with lower grey-matter volume relative to healthy individuals in a number of areas. Conjunction analysis showed smaller volumes in both disorders in clusters in the dorsomedial and ventromedial prefrontal cortex, including the anterior cingulate cortex and bilateral insula. Group comparisons indicated that findings of smaller grey-matter volumes relative to controls in the right dorsolateral prefrontal cortex and left hippocampus, along with cerebellar, temporal and parietal regions were more substantial in major depression. These results suggest that MDD and BD are characterised by both common and distinct patterns of grey-matter volume changes. This combination of differences and similarities has the potential to inform the development of diagnostic biomarkers for these conditions.
The control of environmental pollution has demanded increasingly determination of sulphur in a variety of matrices. Different analytical methods have been developed for the determination of this ...analyte in biodiesel fuel using various analytical techniques, including spectroanalytic and chromatographic methods. In this work a square-wave cathodic adsorptive stripping voltammetric (SW-AdCSV) procedure is proposed for the determination of sulphur in biodiesel, using a glassy carbon electrode modified with mercury-film (MFE). A buffer solution containing sodium acetate 1.4molL−1 and acetic acid 2% was used as supporting electrolyte in two different media (methanol an propanol). The voltammetric measurements were performed adding 70μL of biodiesel sample previously treated with tetramethylammonium hydroxide (TMAH) to the supporting electrolyte. The method showed good linearity (r=0.998) in the determination of sulphur in biodiesel (medium-concentration of 2.68×10−8molL−1 (1.07×10−3mgkg−1) for a confidential level of 95%. Low values of limit of detection-LOD (3.29×10−10molL−1 (1.32×10−5mgkg−1) and limit of quantification-LOQ (1.10×10−9molL−1 (4.40×10−5mgkg−1) indicate a good sensitivity of the method. A validation of the procedure was carried out by comparing this procedure with the results obtained by an official method, using the same sample, through Teste-t of Student (confidence level of 95%). These results indicated that both methods are statistically equivalent, thus demonstrating the feasibility of the new method.
Fully transparent thin‐film transistors (TFTs) are produced at room temperature by radiofrequency magnetron sputtering. Measuring the drain current (IDS) as a function of drain voltage (VDS) at ...different gate voltages (VGS) shows the TFTs possess “hard saturation” with on‐currents of about 0.2 mA (see Figure) and saturation mobilities of 20 cm2 V–1 s–1. The optical and electrical properties and the compatibility of the fabrication process with low‐cost plastic substrates show promise for invisible and flexible electronic circuits.
Measuring cortisol levels as a stress biomarker is essential in many medical conditions associated with a high risk of metabolic syndromes such as anxiety and cardiovascular diseases, among others. ...One technology that has a growing interest in recent years is fiber optic biosensors that enable ultrasensitive cortisol detection. Such interest is allied with progress being achieved in basic interrogation, accuracy improvements, and novel applications. The development of improved cortisol monitoring, with a simplified manufacturing process, high reproducibility, and low cost, are challenges that these sensing mechanisms still face, and for which solutions are still needed. In this paper, a comprehensive characterization of a D-shaped fiber optic immunosensor for cortisol detection based on surface plasmon resonance (SPR) enabled by gold coating is reported. Specifically, the sensor instrumentation and fabrication processes are discussed in detail, and a simulation with its complete mathematical formalism is also presented. Moreover, experimental cortisol detection tests were performed for a detection range of 0.01 to 100 ng/mL, attaining a logarithmic sensitivity of 0.65 ± 0.02 nm/log(ng/mL) with a limit of detection (LOD) of 1.46 ng/mL. Additionally, an investigation of signal processing is also discussed, with the main issues addressed in order to highlight the best way to extract the sensing information from the spectra measured with a D-shaped sensor.
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