Nanomedicines for active targeting: physico-chemical characterization of paclitaxel-loaded anti-HER2 immunonanoparticles and in vitro functional studies on target cells.

Paclitaxel (Tx)-loaded anti-HER2 immunonanoparticles (NPs-Tx-HER) were prepared by the covalent coupling of humanized monoclonal anti-HER2 antibodies (trastuzumab, Herceptin) to Tx-loaded poly (dl-lactic acid) nanoparticles (NPs-Tx) for the active targeting of tumor cells that overexpress HER2 receptors. The physico-chemical properties of NPs-Tx-HER were compared to unloaded immunonanoparticles (NPs-HER) to assess the influence of the drug on anti-HER2 coupling to the NP surface. The immunoreactivity of sulfo-MBS activated anti-HER2 mAbs and the in vitro efficacy of NPs-Tx-HER were tested on SKOV-3 ovarian cancer cells that overexpress HER2 antigens. Tx-loaded nanoparticles (NPs-Tx) obtained by a salting-out method had a size of 171+/-22 nm (P.I.=0.1) and an encapsulation efficiency of about of 78+/-10%, which corresponded to a drug loading of 7.8+/-0.8% (w/w). NPs-Tx were then thiolated and conjugated to activated anti-HER2 mAbs to obtain immunonanoparticles of 237+/-43 nm (P.I.=0.2). The influence of the activation step on the immunoreactivity of the mAbs was tested on SKOV-3 cells using 125I-radiolabeled mAbs, and the activity of the anti-HER2 mAbs was minimally affected after sulfo-MBS functionalization. Approximately 270 molecules of anti-HER2 mAbs were bound per nanoparticle. NPs-Tx-HER exhibited a zeta potential of 0.2+/-0.1 mV. The physico-chemical properties of the Tx-loaded immunonanoparticles were very similar to unloaded immunonanoparticles, suggesting that the encapsulation of the drug did not influence the coupling of the mAbs to the NPs. No drug loss was observed during the preparation process. DSC analysis showed that encapsulated Tx is in an amorphous or disordered-crystalline phase. These results suggest that Tx is entrapped in the polymeric matrix and not adsorbed to the surface of the NPs. In vitro studies on SKOV-3 ovarian cancer cells demonstrated the greater cytotoxic effect of NPs-Tx-HER compared to other Tx formulations. The results showed that at 1 ng Tx/ml, the viability of cells incubated with drug encapsulated in NP-Tx-HER was lower (77.32+/-5.48%) than the viability of cells incubated in NPs-Tx (97.4+/-12%), immunonanoparticles coated with Mabthera, as irrelevant mAb (NPs-Tx-RIT) (93.8+/-12%) or free drug (92.3+/-9.3%).

Expected impact of applying new 2013 AHA/ACC cholesterol guidelines criteria on the recommended lipid target achievement after acute coronary syndromes.

BACKGROUND: 2013 AHA/ACC guidelines on the treatment of cholesterol advised to tailor high-intensity statin after ACS, while previous ATP-III recommended titration of statin to reach low-density lipoprotein cholesterol (LDL-C) targets. We simulated the impact of this change of paradigm on the achievement of recommended targets. METHODS: Among a prospective cohort study of consecutive patients hospitalized for ACS from 2009 to 2012 at four Swiss university hospitals, we analyzed 1602 patients who survived one year after recruitment. Targets based on the previous guidelines approach was defined as (1) achievement of LDL-C target < 1.8 mmol/l, (2) reduction of LDL-C ≥ 50% or (3) intensification of statin in patients who did not reach LDL-C targets. Targets based on the 2013 AHA/ACC guidelines approach was defined as the maximization of statin therapy at high-intensity in patients aged ≤75 years and moderate- or high-intensity statin in patients >75 years. RESULTS: 1578 (99%) patients were prescribed statin at discharge, with 1120 (70%) at high-intensity. 1507 patients (94%) reported taking statin at one year, with 909 (57%) at high-intensity. Among 482 patients discharged with sub-maximal statin, intensification of statin was only observed in 109 patients (23%). 773 (47%) patients reached the previous LDL-C targets, while 1014 (63%) reached the 2013 AHA/ACC guidelines targetsone year after ACS (p value < 0.001). CONCLUSION: The application of the new 2013 AHA/ACC guidelines criteria would substantially increase the proportion of patients achieving recommended lipid targets one year after ACS. Clinical trial number, NCT01075868.

Carbon and oxygen isotope working standards from C-3 and C-4 photosynthates

A preparation of organic working standards for the online measurement of C-13/C-12 and O-18/O-16 ratios in biological material is presented. The organic working standards are simple and inexpensive C-3 and C-4 carbohydrates ( sugars or cellulose) from distinct geographic origin, including white sugar, toilet and XEROX papers from Switzerland, maize from Ivory Coast, cane sugar from Brazil, papyrus from Egypt, and the core of the stem of a Cyperus papyrus plant from Kenya. These photosynthetic products were compared with International Atomic Energy standards CH-3 and CH-6 and other calibration materials. The presented working standards cover a 15 parts per thousand range of C-13/C-12 ratios and 9 parts per thousand for O-18/O-16, with a precision < +/- 0.2 parts per thousand for n > 10.

Emission of carbon nanofiber (CNF) from CNF-containing composite adsorbents

In spite of numerous applications of carbon nanofibers (CNFs) in a variety of fields, the potential release of airborne CNF during their special application, which could lead to workers or end-users exposure, has not been well investigated. In this study, the potential release of CNF from an organic vapour respirator cartridge was evaluated by carbon analysis and microscopy analysis. The cartridge consisted of an AC (Activated Carbon)/CNF composite adsorbent and different types of particulate filters. The composite adsorbent CNF were prepared by chemical vapour deposition (CVD). Air was passed through the prepared cartridge for 12 hours at 12 l/min and particles were collected on sampling filters suitable for measuring organic and elemental carbon (OC/EC) by carbon analysis based on the NIOSH 5040 method. Breakthrough of CNFs was also checked by scanning and transmission electron microscopy (SEM/TEM). This study found only minimal amounts of released elemental carbon while passing the air through the cartridge. Meanwhile TEM photos showed a few CNF structures for AC/CNF composite adsorbents which were not in the critical range in terms of length, aspect ratio, or number. [Authors]

End-tidal carbon dioxide monitoring using a naso-buccal sensor is not appropriate to monitor capnia during non-invasive ventilation.

BACKGROUND: In acute respiratory failure, arterial blood gas analysis (ABG) is used to diagnose hypercapnia. Once non-invasive ventilation (NIV) is initiated, ABG should at least be repeated within 1 h to assess PaCO2 response to treatment in order to help detect NIV failure. The main aim of this study was to assess whether measuring end-tidal CO2 (EtCO2) with a dedicated naso-buccal sensor during NIV could predict PaCO2 variation and/or PaCO2 absolute values. The additional aim was to assess whether active or passive prolonged expiratory maneuvers could improve the agreement between expiratory CO2 and PaCO2. METHODS: This is a prospective study in adult patients suffering from acute hypercapnic respiratory failure (PaCO2 ≥ 45 mmHg) treated with NIV. EtCO2 and expiratory CO2 values during active and passive expiratory maneuvers were measured using a dedicated naso-buccal sensor and compared to concomitant PaCO2 values. The agreement between two consecutive values of EtCO2 (delta EtCO2) and two consecutive values of PaCO2 (delta PaCO2) and between PaCO2 and concomitant expiratory CO2 values was assessed using the Bland and Altman method adjusted for the effects of repeated measurements. RESULTS: Fifty-four datasets from a population of 11 patients (8 COPD and 3 non-COPD patients), were included in the analysis. PaCO2 values ranged from 39 to 80 mmHg, and EtCO2 from 12 to 68 mmHg. In the observed agreement between delta EtCO2 and deltaPaCO2, bias was -0.3 mmHg, and limits of agreement were -17.8 and 17.2 mmHg. In agreement between PaCO2 and EtCO2, bias was 14.7 mmHg, and limits of agreement were -6.6 and 36.1 mmHg. Adding active and passive expiration maneuvers did not improve PaCO2 prediction. CONCLUSIONS: During NIV delivered for acute hypercapnic respiratory failure, measuring EtCO2 using a dedicating naso-buccal sensor was inaccurate to predict both PaCO2 and PaCO2 variations over time. Active and passive expiration maneuvers did not improve PaCO2 prediction. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01489150.

Leishmaniavirus : a possible target against metastatic leishmaniasis

Leishmaniasis is widely spread disease found in bath tropical and temperate regions but limited to the habitat of its sand fly vector. lt affects over 12 million people with 2 million new cases each year. As cutaneous leishmaniasis patients show varying levels of immunity to the disease after recovery, the development of a vaccine has much promise as a prevention strategy. Unfortunately however, existing anti-leishmanial vaccines are plagued by safety issues and have only ever shown limited efficacy .So, despite much effort, no effective vaccine is currently available. Recent studies suggest a correlation between the presence of Leishmania RNA virus (LRV) and the development of mucocutaneous leishmaniasis (MCL), which is characterised by the presence of secondary lesions in nasal and buccal mucosa, causing destructive and disfiguring facial lesions. Moreover, recent research has associated the viral presence to treatment fa ilure in patients. ln the first part of this work, we propose that these viral particles may serve as promising vaccine candidates due to their powerful TLR-3 antigenicity, launching an early cell-mediated attack on stimulated cells and thus eliminating their virulent complications. The second part of this work discusses a preliminary study on the lymphocyte immune response against Leishmania guyanensis infection. The lymphocyte response (and in particular, the raie of CDS+ T cells) is controversial and varies greatly between Leishmania species. Here, we illustrate the importance of a small CDS+ T cell subpopulation, expressing the CDSaa+ receptor. These intraepithelial lymphocytes are mainly present in the skin, vagina and intestinal tissue and are best known for their raie in the early immune response against pathogens. Similarly to traditional CDS+ cells, they secrete the tissue-destructive enzymes, perforin and granzyme, which can result in a hyper-inflammatory cutaneous lesion, raising a possibility for their raie in Leishmania infection. lndeed, our initial results in a murine mode( of Leishmania guyanensis infection suggest a pathogenic raie for CDSaa+ T cells. Further research into species-specific immune responses against the various Leishmania parasites is critical to realising the clinical potential of immunotherapy in the treatment and prevention of this disfiguring disease . -- La Leishmaniose est une maladie infectieuse causée par le parasite Leishmania. Elle est localisée dans les régions où son vecteur se reproduit, c'est-à-dire dans des régions tropicales ou tempérées. Cette pathologie affecte 12 millions des personnes dans le monde et 2 millions de nouveaux cas sont recensés chaque année. D'autres facteurs, tels la déforestation, les conditions d'hygiène ou encore l'accès limité aux médicaments, aggravent la pathologie et renforcent sa propagation. Les patients affectés par la leishmaniose et qui arrivent à en guérir, présentent une protection contre une réinfection. Pour cette raison, le développement d'un vaccin reste la meilleure solution pour combattre ce fléau. Mais, à ce jour, et malgré beaucoup d'efforts, aucun vaccin efficace n'a encore été développé. Un autre facteur responsable de l'aggravation de la pathologie et de la résistance de ces parasites aux drogues est un virus qui peut infecter certaines souches de Leishmania. Ce virus, appelé Leishmania RNA virus, peut induire une réponse inflammatoire exagérée, ce qui a comme résultat l'aggravation de la pathologie, la survie et la dissémination de ce parasite au sein de l'hôte infecté. Vu l'absence d'un vaccin contre ce parasite, Leishmania, nous proposons de développer un vaccin non pas contre le parasite lui- même mais contre l'agent qui provoque l'exacerbation de la pathologie, c'est-à-dire le virus. Dans cette étude, nous décrivons le développement d'un vaccin contre LRV, qui empêche le parasite d'induire des inflammations exagérées dans les souris. En d'autres mots, nous essayons de prévenir toutes les complications générées par cet hyperpathogène qu'est le LRV, en utilisant sa capside comme cible pour le développement d'un vaccin. Dans la deuxième partie de ce manuscrit, nous avons aussi étudié plus en détail la réponse immunitaire, et en particulier la réponse des lymphocytes T COB suite à l'infection du parasite Leishmania guyanensis porteur du LRV.