New generation of electrochemical immunoassay based on polymeric nanoparticles for early detection of breast cancer

Screening and early diagnosis are the key factors for the reduction of mortality rate and treatment cost of cancer. Therefore, sensitive and selective methods that can reveal the low abundance of cancer biomarkers in a biological sample are always desired. Here, we report the development of a novel electrochemical biosensor for early detection of breast cancer by using bioconjugated self-assembled pH-responsive polymeric micelles. The micelles were loaded with ferrocene molecules as "tracers" to specifically target cell surface-associated epithelial mucin (MUC1), a biomarker for breast and other solid carcinoma. The synthesis of target-specific, ferrocene-loaded polymeric micelles was confirmed, and the resulting sensor was capable of detecting the presence of MUC1 in a sample containing about 10 cells/mL. Such a high sensitivity was achieved by maximizing the loading capacity of ferrocene inside the polymeric micelles. Every single event of binding between the antibody and antigen was represented by the signal of hundreds of thousands of ferrocene molecules that were released from the polymeric micelles. This resulted in a significant increase in the intensity of the ferrocene signal detected by cyclic voltammetry

A new class of smart gadolinium contrast agent for tissue pH probing using magnetic resonance imaging

Detecting tissue pH in vivo is extremely vital for medical diagnosis and formulation of treatment decisions. To this end, many investigations have been carried out to develop an accurate and efficient method of in vivo pH measurement. Most of the techniques developed so far suffer from inadequate accuracy, due to poor sensitivity at low concentration of the target or nonspecific interactions within the tissue matrix. To overcome these issues, we describe herein the development of a simple, yet reliable, way to estimate pH with high precision using a Gd(III)-DOTA-silyl-based acid-labile group as a pH-sensitive contrast agent with Magnetic Resonance Imaging (MRI). With this method, a change in T1 weighted image intensity of the newly developed pH-sensitive contrast is directly linked to the proton concentration in the media. As a result, we were able estimate the pH of the target with 95% reliability

Isolation and fatty acid profile of selected microalgae strains from the Red Sea for biofuel production

The isolation of lipid-rich autochthonous strains of microalgae is a crucial stage for the development of a microalgae-based biofuel production plant, as these microalgae already have the necessary adaptations to withstand competition, predation and the temperatures observed at each production site. This is particularly important in extreme climates such as in Saudi Arabia. Resorting to fluorescence activated cell sorting (FACS) we screened for and isolated several microalgal strains from samples collected from the Red Sea. Relying on the fluorescence of BODIPY 505/515 (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diazasindacene) and growth performance, four promising candidates were identified and the total lipid content and fatty acid profile was assessed for biofuels production. Selected isolates were classified as chlorophytes, belonging to three different genera: Picochlorum, Nannochloris and Desmochloris. The lipid contents were assessed microscopically by means of BODIPY 505/515-associated fluorescence to detect intracellular lipid bodies, which revealed several lipid drops in all selected strains. This result was confirmed by lipid gravimetric determination, which demonstrated that all strains under study presented inner cell lipid contents ranging from 20% to 25% of the biomass dry weight. Furthermore, the fatty acid methyl esters profile of all strains seems ideal for biodiesel production due to a low degree of polyunsaturated fatty acid methyl esters and high amount of palmitic and oleic acids.NPST Program of King Saud University [11-ENE1719-02]info:eu-repo/semantics/publishedVersio

A nanoparticle comprising a micelle formed by an amphiphilic block copolymer and encapsulating a gadolinium complex

Publication number: WO2011/113616The present invention relates to a nanoparticle comprising a micelle formed by an amphophilic block-copolymer and an agent encapsulated within said micelle. The present invention also relates to a composition comprising such nanoparticle and to the use of such nanoparticle and/or of such composition. More particularly, in one embodiment, the invention describes a new class of polymeric nanoparticles as smart Tl contrast agent for MR imaging for breast cancer early detection. These nanoparticles contrast agents have the capability to remain switched off during circulation and then switch on their imaging capacity upon arrival at the target sites (tissue of interest). These smart nanoparticles contrast agent are self-assembled from pH sensitive amphiphilic polymer, loaded with Gadolinium (Gd3+) complex based Tl agent and then fitted with targeting biomolecules such as antibody, small molecules or DNA to increase its specificity toward the target of interest

Bioprospecting autochthonous marine microalgae strain from the Arabian Gulf Seawater, Kuwait for biofuel feedstocks

Bioprospecting programs are the key to increasing the current portfolio of indigenous microalgal strains accessible for different applications in microalgal biotechnology. In this work, nine fast-growing microalgal strains isolated from Kuwait's Arabian/Persian Gulf coastal waters were evaluated for their potential as biofuel feedstocks. 18S rRNA gene sequencing showed that the strains belong to five different genera: Chlorella, Nannochloris, Scenedesmus, Tetraselmis, and Nannochloropsis. In terms of the total lipid content, in comparison to the other strains, Tetraselmis sp. KUBS13G and Tetraselmis sp. KUBS16G displayed higher lipid contents of 29.56% dry weight (DW) and 26.13% DW, respectively, dominated by palmitic and oleic acids. Fuel properties calculated from the fatty acid methyl esters (FAMES) by empirical equations were compared with EN14214 (European) and ASTM D6751--02 (American) biodiesel standards. Multicriteria decision analysis (MCDA) methods, such as the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) and Graphical Analysis for Interactive Assistance (GALA), were used to select suitable microalgae for biofuel feedstock based on their biodiesel fuel properties. Overall, the results suggested that the indigenous microalgal strain Tetraselmis, particularly Tetraselmis sp. KUBS37G, and Scenedesmus sp. KUB Sl7R are the most suitable strains for biofuel feedstock owing to their improved fuel properties, such as density (rho) (0.88 g cm-3), low kinematic viscosity (3.1 mm2 s-1), high cetane number (54 and 56, respectively), high oxidation stability (14.6 hr and 14.8 hr), and cold filter plugging point (1.0 degrees C and -6.1 degrees C).info:eu-repo/semantics/publishedVersio

Self-assembled polymeric nanoparticles as new, smart contrast agents for cancer early detection using magnetic resonance imaging

Early cancer detection is a major factor in the reduction of mortality and cancer management cost. Here we developed a smart and targeted micelle-based contrast agent for magnetic resonance imaging (MRI), able to turn on its imaging capability in the presence of acidic cancer tissues. This smart contrast agent consists of pH-sensitive polymeric micelles formed by self-assembly of a diblock copolymer (poly(ethyleneglycol-b-trimethylsilyl methacrylate)), loaded with a gadolinium hydrophobic complex ((t)BuBipyGd) and exploits the acidic pH in cancer tissues. In vitro MRI experiments showed that (t)BuBipyGd-loaded micelles were pH-sensitive, as they turned on their imaging capability only in an acidic microenvironment. The micelle-targeting ability toward cancer cells was enhanced by conjugation with an antibody against the MUC1 protein. The ability of our antibody-decorated micelles to be switched on in acidic microenvironments and to target cancer cells expressing specific antigens, together with its high Gd(III) content and its small size (35-40 nm) reveals their potential use for early cancer detection by MRI

Biological activities and chemical composition of methanolic extracts of selected Autochthonous microalgae strains from the Red Sea

Four lipid-rich microalgal species from the Red Sea belonging to three different genera (Nannochloris, Picochlorum and Desmochloris), previously isolated as novel biodiesel feedstocks, were bioprospected for high-value, bioactive molecules. Methanol extracts were thus prepared from freeze-dried biomass and screened for different biological activities. Nannochloris sp. SBL1 and Desmochloris sp. SBL3 had the highest radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, and the best copper and iron chelating activities. All species had potent butyrylcholinesterase inhibitory activity (>50%) and mildly inhibited tyrosinase. Picochlorum sp. SBL2 and Nannochloris sp. SBL4 extracts significantly reduced the viability of tumoral (HepG2 and HeLa) cells with lower toxicity against the non-tumoral murine stromal (S17) cells. Nannochloris sp. SBL1 significantly reduced the viability of Leishmania infantum down to 62% (250 mu g/mL). Picochlorum sp. SBL2 had the highest total phenolic content, the major phenolic compounds identified being salicylic, coumaric and gallic acids. Neoxanthin, violaxanthin, zeaxanthin, lutein and -carotene were identified in the extracts of all strains, while canthaxanthin was only identified in Picochlorum sp. SBL2. Taken together, these results strongly suggest that the microalgae included in this work could be used as sources of added-value products that could be used to upgrade the final biomass value.National Science, Technology and Innovation Program of King Abdulaziz Medical City for Science and Technology, Riyadh, Saudi Arabia [NPST, 11-ENE 1719-02]; Foundation for Science and Technology (FCT), Portugal [SFRH/BD/78062/2011]; FCT [IF/00049/2012, SFRH/BPD/86071/2012, Pest-OE/QUI/UI0612/2013]info:eu-repo/semantics/publishedVersio

Natural Polysaccharides as Preventive and Therapeutic Horizon for Neurodegenerative Diseases

Neurodegenerative diseases are a serious and widespread global public health burden amongst aging populations. The total estimated worldwide global cost of dementia was US$818 billion in 2015 and has been projected to rise to 2 trillion US$ by 2030. While advances have been made to understand different neurodegenerative disease mechanisms, effective therapeutic strategies do not generally exist. Several drugs have been proposed in the last two decades for the treatment of different types of neurodegenerative diseases, with little therapeutic benefit, and often with severe adverse and side effects. Thus, the search for novel drugs with higher efficacy and fewer drawbacks is an ongoing challenge in the treatment of neurodegenerative disease. Several natural compounds including polysaccharides have demonstrated neuroprotective and even therapeutic effects. Natural polysaccharides are widely distributed in plants, animals, algae, bacterial and fungal species, and have received considerable attention for their wide-ranging bioactivity, including their antioxidant, anti-neuroinflammatory, anticholinesterase and anti-amyloidogenic effects. In this review, we summarize different mechanisms involved in neurodegenerative diseases and the neuroprotective effects of natural polysaccharides, highlighting their potential role in the prevention and therapy of neurodegenerative disease