52 research outputs found
D2B-Functionalized Gold Nanoparticles: Promising Vehicles for Targeted Drug Delivery to Prostate Cancer
Despite the multitude of therapeutic agents available to treat prostate cancer (PC), there are still no effective and safe measures to treat the tumor. It remains a challenge to develop a simple approach to target PC with specific antibodies. In our study, D2B monoclonal antibodies against a prostate-specific membrane antigen (PSMA) were used. We investigated the functionalization of gold nanoparticles (AuNPs) with D2B to generate favorable physicochemical and biological properties that mediate specific binding to PC. For this purpose, AuNPs with a size of about 25 nm were synthesized in water using sodium citrate as a reducing and stabilizing agent and then coated with D2B. Major physicochemical properties of naked and D2B-coated AuNPs were investigated by ultraviolet−visible (UV−vis) spectroscopy, dynamic light scattering (DLS), and zeta potential measurements. The successful binding of D2B to AuNPs-citrate caused a 15 nm red shift in the UV−vis. This was assessed by DLS as an increase in zeta potential from ∼−45 to ∼−23 mV and in the size of AuNPs from ∼25 to ∼63 nm. Scanning electron microscopy confirmed the size shift of AuNPs, which was detected as an exterior organic layer of D2Bs surrounding each AuNP. Even at high exposure levels of the bioconjugates, PSMA-PC-3 cells exhibited minimal cytotoxicity. The specific and dose-dependent binding of AuNPs-D2B to PC-3- PSMA cells was validated by flow cytometry analysis. Our data provide effective drug delivery systems in PC theranostics
Assessment of charged AuNPs: from synthesis to innate immune recognition
Gold nanoparticle (AuNP) physicochemical characteristics, mainly size and charge, modulate their biodistribution, cytotoxicity, and immunorecognition as reported from in vitro and in vivo studies. While data from in vitro studies could be biased by several factors including activation of cells upon isolation and lack of sera proteins in the microenvironment of primary generated cell lines, in vivo studies are costly and time-consuming and require ethics consideration. In this study, we developed a simple and novel in vivo-like method to test for NP immunorecognition from freshly withdrawn human blood samples. AuNPs with a size range of 30 ± 5 nm coated with cationic poly(L-lysine) (PLL) dendrigraft and slightly negative poly(vinyl alcohol) (PVA) were synthesized in water. PLL-capped AuNPs were further coated with poly(ethylene glycol) (PEG) to obtain nearly neutrally charged PEG-AuNPs. Physicochemical properties were determined using zeta potential measurements, UV-Vis spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM). Gel electrophoretic separation, zeta potential, and DLS were also used to characterize our NPs after human blood plasma treatment. PLL-AuNPs showed similar variation in charge and binding affinity to plasma proteins in comparison with PVA-AuNPs. However, PLL-AuNPs.protein complexes revealed a drastic change in size compared to the other tested particles. Results obtained from the neutrophil function test and pyridine formazan extraction revealed the highest activation level of neutrophils (~70%) by 50 μg/mL of PLL-AuNPs compared to a null induction by PEG- and PVA-AuNPs. This observation was further verified by flow cytometry analysis of polymorphonuclear cell size variation in the presence of coated AuNPs. Overall, our in vivo-like method, to test for NP immunorecognition, proved to be reliable and effective. Finally, our data supports the use of PEG-AuNPs as promising vehicles for drug delivery, as they exhibit minimal protein adsorption affinity and insignificant charge and size variation once introduced in whole blood
Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19
Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies
There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity
Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study
Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe
Pretreatment of Miscanthus x giganticus : towards an optimal valorization of lignocellulosic biomass
Le miscanthus x Giganteus (MxG) constitue, du fait de sa composition, une source renouvelable de matière lignocellulosique pouvant être d'un grand intérêt pour la production de molécules à haute valeur ajoutée. Le MxG ayant servi à ce travail provient du lycée agricole à Courcelles-Chaussy, Metz-France. Sa teneur élevée en hémicelluloses (26 %), en lignine (26 %) et en cellulose (36 %) en fait une bonne source de polymères et de carburant renouvelable. L'étude que nous avons réalisée a été menée dans le but de caractériser la paille de MxG et d'optimiser le processus de délignification en une seule étape (1) par un traitement organosolv à l'éthanol et en deux étapes (2) par un prétraitement consistant en une autohydrolyse à l'eau/organosolv. Le procédé éthanol organosolv a permis un bon fractionnement des trois constituants de la biomasse (la lignine, la cellulose et les hémicelluloses). Le procédé de traitement en deux étapes, impliquant une autohydrolyse à l'eau (en présence et en l'absence du 2-naphtol), préalable au traitement organosolv, a permis de faciliter l'étape ultérieure de délignification en déstructurant la lignine. Une investigation portant sur la structure physico-chimique a été réalisée sur de la lignine de bois broyé et de la lignine organosolv de MxG extraite à différentes sévérités de traitement. Nous nous sommes ensuite intéressés à utiliser la lignine organosolv pour la formulation d'un adhésif pour le bois dans laquelle un aldéhyde non toxique et peu volatile (le glyoxal) est employé en remplacement du formaldéhyde. Une formulation, composée à 100 % de résines naturelles (60 % de tannins de mimosa et 40 % de lignine glyoxalée) a été utilisée pour la conception d'un panneau de particules et a donné des résultats prometteurs avec une force de liaison interne de 0,41 MPa, supérieure à la valeur de la norme européenne en vigueur. Enfin, une étude des propriétés antioxydantes a été faite sur les lignines extraites. Les résultats obtenus ont montré une corrélation entre l'activité antioxydante et les conditions opératoires du traitement organosolv, la masse moléculaire moyenne, l'indice de polydispersité et les groupements hydroxyles phénoliques des lignines.Miscanthus x giganteus (MxG) is, because of its composition, a source of renewable lignocellulosic material that can be of great interest for the production of high added value molecules. MxG used in this work comes from the agricultural high school of Courcelles-Chaussy, Metz-France. Its high content of hemicelluloses (26 %), lignin (26 %) and cellulose (36 %) makes it a good source of polymers and renewable fuel. In the present study we have characterized the straw of MxG and optimized the process of delignification in a single step (1) by an ethanol organosolv treatment and in a two steps (2) including an autohydrolysis pretreatment with water / organosolv. The ethanol organosolv process permits a good separation of the three constituents of our biomass (lignin, cellulose and hemicelluloses). The two steps treatment process, involving an autohydrolysis with water (in the presence or absence of 2-naphthol) before the pretreatment organosolv has facilitated the later stage of delignification in destructurizing the lignin. An investigation of the physico-chemical properties was performed on the structure of the milled wood lignin and organosolv lignin of MxG extracted with different treatment severities. A way of valorization for the organosolv lignin has been proposed by their incorporation in the formulation of an adhesive for wood in which a non volatile and low toxic aldehyde (glyoxal) is used instead of formaldehyde. A formulation consisting in 100 % of natural resins (60 % tannins of mimosa and 40 % of glyoxalated lignin) was used for the production of particle board and gave promising results with internal bond strength of 0.41 MPa, higher than the value of the current European standard. Finally, a study was conducted on the antioxidant properties of organosolv lignin extracted at different severities. The results have shown a correlation between the antioxidant activity and the operating conditions of treatment organosolv, the average molecular weight, the polydispersity index and the phenolic hydroxyl groups of ligni
Prétraitement du miscanthus x giganteus : vers une valorisation optimale de la biomasse lignocellulosique
Miscanthus x giganteus (MxG) is, because of its composition, a source of renewable lignocellulosic material that can be of great interest for the production of high added value molecules. MxG used in this work comes from the agricultural high school of Courcelles-Chaussy, Metz-France. Its high content of hemicelluloses (26 %), lignin (26 %) and cellulose (36 %) makes it a good source of polymers and renewable fuel. In the present study we have characterized the straw of MxG and optimized the process of delignification in a single step (1) by an ethanol organosolv treatment and in a two steps (2) including an autohydrolysis pretreatment with water / organosolv. The ethanol organosolv process permits a good separation of the three constituents of our biomass (lignin, cellulose and hemicelluloses). The two steps treatment process, involving an autohydrolysis with water (in the presence or absence of 2-naphthol) before the pretreatment organosolv has facilitated the later stage of delignification in destructurizing the lignin. An investigation of the physico-chemical properties was performed on the structure of the milled wood lignin and organosolv lignin of MxG extracted with different treatment severities. A way of valorization for the organosolv lignin has been proposed by their incorporation in the formulation of an adhesive for wood in which a non volatile and low toxic aldehyde (glyoxal) is used instead of formaldehyde. A formulation consisting in 100 % of natural resins (60 % tannins of mimosa and 40 % of glyoxalated lignin) was used for the production of particle board and gave promising results with internal bond strength of 0.41 MPa, higher than the value of the current European standard. Finally, a study was conducted on the antioxidant properties of organosolv lignin extracted at different severities. The results have shown a correlation between the antioxidant activity and the operating conditions of treatment organosolv, the average molecular weight, the polydispersity index and the phenolic hydroxyl groups of ligninLe miscanthus x Giganteus (MxG) constitue, du fait de sa composition, une source renouvelable de matière lignocellulosique pouvant être d'un grand intérêt pour la production de molécules à haute valeur ajoutée. Le MxG ayant servi à ce travail provient du lycée agricole à Courcelles-Chaussy, Metz-France. Sa teneur élevée en hémicelluloses (26 %), en lignine (26 %) et en cellulose (36 %) en fait une bonne source de polymères et de carburant renouvelable. L'étude que nous avons réalisée a été menée dans le but de caractériser la paille de MxG et d'optimiser le processus de délignification en une seule étape (1) par un traitement organosolv à l'éthanol et en deux étapes (2) par un prétraitement consistant en une autohydrolyse à l'eau/organosolv. Le procédé éthanol organosolv a permis un bon fractionnement des trois constituants de la biomasse (la lignine, la cellulose et les hémicelluloses). Le procédé de traitement en deux étapes, impliquant une autohydrolyse à l'eau (en présence et en l'absence du 2-naphtol), préalable au traitement organosolv, a permis de faciliter l'étape ultérieure de délignification en déstructurant la lignine. Une investigation portant sur la structure physico-chimique a été réalisée sur de la lignine de bois broyé et de la lignine organosolv de MxG extraite à différentes sévérités de traitement. Nous nous sommes ensuite intéressés à utiliser la lignine organosolv pour la formulation d'un adhésif pour le bois dans laquelle un aldéhyde non toxique et peu volatile (le glyoxal) est employé en remplacement du formaldéhyde. Une formulation, composée à 100 % de résines naturelles (60 % de tannins de mimosa et 40 % de lignine glyoxalée) a été utilisée pour la conception d'un panneau de particules et a donné des résultats prometteurs avec une force de liaison interne de 0,41 MPa, supérieure à la valeur de la norme européenne en vigueur. Enfin, une étude des propriétés antioxydantes a été faite sur les lignines extraites. Les résultats obtenus ont montré une corrélation entre l'activité antioxydante et les conditions opératoires du traitement organosolv, la masse moléculaire moyenne, l'indice de polydispersité et les groupements hydroxyles phénoliques des lignines
Prétraitement du miscanthus x giganteus (vers une valorisation optimale de la biomasse lignocellulosique)
Le miscanthus x Giganteus (MxG) constitue, du fait de sa composition, une source renouvelable de matière lignocellulosique pouvant être d'un grand intérêt pour la production de molécules à haute valeur ajoutée. Le MxG ayant servi à ce travail provient du lycée agricole à Courcelles-Chaussy, Metz-France. Sa teneur élevée en hémicelluloses (26 %), en lignine (26 %) et en cellulose (36 %) en fait une bonne source de polymères et de carburant renouvelable. L'étude que nous avons réalisée a été menée dans le but de caractériser la paille de MxG et d'optimiser le processus de délignification en une seule étape (1) par un traitement organosolv à l'éthanol et en deux étapes (2) par un prétraitement consistant en une autohydrolyse à l'eau/organosolv. Le procédé éthanol organosolv a permis un bon fractionnement des trois constituants de la biomasse (la lignine, la cellulose et les hémicelluloses). Le procédé de traitement en deux étapes, impliquant une autohydrolyse à l'eau (en présence et en l'absence du 2-naphtol), préalable au traitement organosolv, a permis de faciliter l'étape ultérieure de délignification en déstructurant la lignine. Une investigation portant sur la structure physico-chimique a été réalisée sur de la lignine de bois broyé et de la lignine organosolv de MxG extraite à différentes sévérités de traitement. Nous nous sommes ensuite intéressés à utiliser la lignine organosolv pour la formulation d'un adhésif pour le bois dans laquelle un aldéhyde non toxique et peu volatile (le glyoxal) est employé en remplacement du formaldéhyde. Une formulation, composée à 100 % de résines naturelles (60 % de tannins de mimosa et 40 % de lignine glyoxalée) a été utilisée pour la conception d'un panneau de particules et a donné des résultats prometteurs avec une force de liaison interne de 0,41 MPa, supérieure à la valeur de la norme européenne en vigueur. Enfin, une étude des propriétés antioxydantes a été faite sur les lignines extraites. Les résultats obtenus ont montré une corrélation entre l'activité antioxydante et les conditions opératoires du traitement organosolv, la masse moléculaire moyenne, l'indice de polydispersité et les groupements hydroxyles phénoliques des lignines.Miscanthus x giganteus (MxG) is, because of its composition, a source of renewable lignocellulosic material that can be of great interest for the production of high added value molecules. MxG used in this work comes from the agricultural high school of Courcelles-Chaussy, Metz-France. Its high content of hemicelluloses (26 %), lignin (26 %) and cellulose (36 %) makes it a good source of polymers and renewable fuel. In the present study we have characterized the straw of MxG and optimized the process of delignification in a single step (1) by an ethanol organosolv treatment and in a two steps (2) including an autohydrolysis pretreatment with water / organosolv. The ethanol organosolv process permits a good separation of the three constituents of our biomass (lignin, cellulose and hemicelluloses). The two steps treatment process, involving an autohydrolysis with water (in the presence or absence of 2-naphthol) before the pretreatment organosolv has facilitated the later stage of delignification in destructurizing the lignin. An investigation of the physico-chemical properties was performed on the structure of the milled wood lignin and organosolv lignin of MxG extracted with different treatment severities. A way of valorization for the organosolv lignin has been proposed by their incorporation in the formulation of an adhesive for wood in which a non volatile and low toxic aldehyde (glyoxal) is used instead of formaldehyde. A formulation consisting in 100 % of natural resins (60 % tannins of mimosa and 40 % of glyoxalated lignin) was used for the production of particle board and gave promising results with internal bond strength of 0.41 MPa, higher than the value of the current European standard. Finally, a study was conducted on the antioxidant properties of organosolv lignin extracted at different severities. The results have shown a correlation between the antioxidant activity and the operating conditions of treatment organosolv, the average molecular weight, the polydispersity index and the phenolic hydroxyl groups of ligninNANCY1-Bib. numérique (543959902) / SudocSudocFranceF
Novel Foaming-Agent Free Insulating Geopolymer Based on Industrial Fly Ash and Rice Husk
This study highlights the synthesis of a new thermal insulating geopolymer based on the alkaline activation of fly ashes. A porous geopolymer material can be prepared without the addition of a foaming agent, using high ratio solution/ashes (activating solutions used are water, sodium or potassium hydroxide). In order to increase the porosity of the material and to make it more ecological, rice husks are incorporated into the formulation. The geopolymer materials were prepared at room temperature and dried at moderate temperature (105 °C) by a simple procedure. The microstructural characteristics of these new porous geopolymers were assessed by optical microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and X-ray fluorescence (XRF). Infrared spectroscopy (FTIR) was used to confirm the geopolymerisation. The effect of the ratio solution/ashes and the percentage of the rice husk addition on thermal and mechanical analysis was evaluated. An insulating material for a solution/ashes ratio of 0.9 and a rice husk content of 15% having a λ value of 0.087 W/(m·K), a porosity of 61.4% and an Rc value of 0.1 MPa was successfully prepared
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