Fluorescence Properties of Photonic Crystals Doped with Perylenediimide

This study aims to present the fabrication of colloidal photonic crystals (PC) with increased fluorescence properties. The use of a highly fluorescent perylenediimide derivate (PDI) during the soap-free emulsion polymerization of styrene–acrylic acid resulted in monodisperse core–shell particles which allowed the fabrication of PC films. The properties of the hybrid material were studied in comparison with hybrid materials obtained by impregnation of films with chromophore solutions. In both cases an increase of the fluorescence response was observed in addition to a blue shift for the PDI core particles, proving the incorporation of the dye inside the copolymer particles

Cross-linkable azido C60-fullerene derivatives for efficient thermal stabilization of polymer bulk-heterojunction solar cells

International audienceOriginal [60]PCBM-inspired fullerene derivatives bearing an azidofunctional group were synthesized. By incorporating an optimizedquantity of this thermal cross-linker additive in the P3HT:[60]PCBMphotoactive layer, an impressive stabilization of the bulk-heterojunctionmorphology at its optimal photovoltaic performance wasachieved

Limited role of culture conversion for decision-making in individual patient care and for advancing novel regimens to confirmatory clinical trials

Supported by the European and Developing Country Clinical Trials Partnership (grant IP.2007.32011.011) and the Global Alliance for TB Drug Development, with support from the Bill & Melinda Gates Foundation, US Agency for International Development, UK Department for International Development, Directorate-General for International Cooperation of the Netherlands, Irish Aid and Australian Department of Foreign Affairs and Trade.Background Despite recent increased clinical trials activity, no regimen has proved able to replace the standard 6-month regimen for drug-sensitive tuberculosis. Understanding the relationship between microbiological markers measured during treatment and long-term clinical outcomes is critical to evaluate their usefulness for decision-making for both individual patient care and for advancing novel regimens into time-consuming and expensive pivotal phase III trials. Methods Using data from the randomized controlled phase III trial REMoxTB, we evaluated sputum-based markers of speed of clearance of bacilli: time to smear negative status; time to culture negative status on LJ or in MGIT; daily rate of change of log10(TTP) to day 56; and smear or culture results at weeks 6, 8 or 12; as individual- and trial-level surrogate endpoints for long-term clinical outcome. Results Time to culture negative status on LJ or in MGIT, time to smear negative status and daily rate of change in log10(TTP) were each independent predictors of clinical outcome, adjusted for treatment (p <0.001). However, discrimination between low and high risk patients, as measured by the c-statistic, was modest and not much higher than the reference model adjusted for BMI, history of smoking, HIV status, cavitation, gender and MGIT TTP. Conclusions Culture conversion during treatment for tuberculosis, however measured, has only a limited role in decision-making for advancing regimens into phase III trials or in predicting the outcome of treatment for individual patients. REMoxTB ClinicalTrials.gov number: NCT00864383.Publisher PDFPeer reviewe

Limited role of culture conversion for decision-making in individual patient care and for advancing novel regimens to confirmatory clinical trials

Supported by the European and Developing Country Clinical Trials Partnership (grant IP.2007.32011.011) and the Global Alliance for TB Drug Development, with support from the Bill & Melinda Gates Foundation, US Agency for International Development, UK Department for International Development, Directorate-General for International Cooperation of the Netherlands, Irish Aid and Australian Department of Foreign Affairs and Trade.Background Despite recent increased clinical trials activity, no regimen has proved able to replace the standard 6-month regimen for drug-sensitive tuberculosis. Understanding the relationship between microbiological markers measured during treatment and long-term clinical outcomes is critical to evaluate their usefulness for decision-making for both individual patient care and for advancing novel regimens into time-consuming and expensive pivotal phase III trials. Methods Using data from the randomized controlled phase III trial REMoxTB, we evaluated sputum-based markers of speed of clearance of bacilli: time to smear negative status; time to culture negative status on LJ or in MGIT; daily rate of change of log10(TTP) to day 56; and smear or culture results at weeks 6, 8 or 12; as individual- and trial-level surrogate endpoints for long-term clinical outcome. Results Time to culture negative status on LJ or in MGIT, time to smear negative status and daily rate of change in log10(TTP) were each independent predictors of clinical outcome, adjusted for treatment (p <0.001). However, discrimination between low and high risk patients, as measured by the c-statistic, was modest and not much higher than the reference model adjusted for BMI, history of smoking, HIV status, cavitation, gender and MGIT TTP. Conclusions Culture conversion during treatment for tuberculosis, however measured, has only a limited role in decision-making for advancing regimens into phase III trials or in predicting the outcome of treatment for individual patients. REMoxTB ClinicalTrials.gov number: NCT00864383.Publisher PDFPeer reviewe

New fullerene-C60 light-harvesting antennas for dye sensitized solar cells

Date du colloque&nbsp;: 06/2010</p

Using biomarkers to predict TB treatment duration (Predict TB): a prospective, randomized, noninferiority, treatment shortening clinical trial

Background : By the early 1980s, tuberculosis treatment was shortened from 24 to 6 months, maintaining relapse rates of 1-2%. Subsequent trials attempting shorter durations have failed, with 4-month arms consistently having relapse rates of 15-20%. One trial shortened treatment only among those without baseline cavity on chest x-ray and whose month 2 sputum culture converted to negative. The 4-month arm relapse rate decreased to 7% but was still significantly worse than the 6-month arm (1.6%, P<0.01).  We hypothesize that PET/CT characteristics at baseline, PET/CT changes at one month, and markers of residual bacterial load will identify patients with tuberculosis who can be cured with 4 months (16 weeks) of standard treatment.Methods: This is a prospective, multicenter, randomized, phase 2b, noninferiority clinical trial of pulmonary tuberculosis participants. Those eligible start standard of care treatment. PET/CT scans are done at weeks 0, 4, and 16 or 24. Participants who do not meet early treatment completion criteria (baseline radiologic severity, radiologic response at one month, and GeneXpert-detectable bacilli at four months) are placed in Arm A (24 weeks of standard therapy). Those who meet the early treatment completion criteria are randomized at week 16 to continue treatment to week 24 (Arm B) or complete treatment at week 16 (Arm C). The primary endpoint compares the treatment success rate at 18 months between Arms B and C.Discussion: Multiple biomarkers have been assessed to predict TB treatment outcomes. This study uses PET/CT scans and GeneXpert (Xpert) cycle threshold to risk stratify participants. PET/CT scans are not applicable to global public health but could be used in clinical trials to stratify participants and possibly become a surrogate endpoint. If the Predict TB trial is successful, other immunological biomarkers or transcriptional signatures that correlate with treatment outcome may be identified. TRIAL REGISTRATION: NCT02821832

Monomer type emission of perylenediimide derivatives doped polymer particles

This study aims to present the fabrication of colloidal photonic crystals (PCs) doped with perylenediimide (PDI) derivatives. Monodisperse PDI doped core–shell polymer particles have been obtained by employing a soap-free emulsion polymerization process of styrene and 2-hydroxyethylmethacrylate with the chromophore solubilized in the organic phase. The obtained polymer colloids allowed the fabrication of PC films that have been investigated by UV–vis and fluorescence spectroscopy. The hybrid materials have been investigated in comparison with PCs doped by the classical impregnation method. Thus, the doping using soap-free emulsion polymerization resulted in the obtaining of PDI doped core–shell polymer particles exhibiting monomer emission, whereas by employing an impregnation doping method H-type aggregates are formed

Reversible physical interaction between CdSe quantum dots and perylenediimide (PDI) aggregates in aqueous media

International audienc

Discovery of Q203, a potent clinical candidate for the treatment of tuberculosis

New therapeutic strategies are needed to combat the tuberculosis pandemic and the spread of multidrug-resistant (MDR) and extensively drug-resistant (XDR) forms of the disease, which remain a serious public health challenge worldwide1, 2. The most urgent clinical need is to discover potent agents capable of reducing the duration of MDR and XDR tuberculosis therapy with a success rate comparable to that of current therapies for drug-susceptible tuberculosis. The last decade has seen the discovery of new agent classes for the management of tuberculosis3, 4, 5, several of which are currently in clinical trials6, 7, 8. However, given the high attrition rate of drug candidates during clinical development and the emergence of drug resistance, the discovery of additional clinical candidates is clearly needed. Here, we report on a promising class of imidazopyridine amide (IPA) compounds that block Mycobacterium tuberculosis growth by targeting the respiratory cytochrome bc1 complex. The optimized IPA compound Q203 inhibited the growth of MDR and XDR M. tuberculosis clinical isolates in culture broth medium in the low nanomolar range and was efficacious in a mouse model of tuberculosis at a dose less than 1 mg per kg body weight, which highlights the potency of this compound. In addition, Q203 displays pharmacokinetic and safety profiles compatible with once-daily dosing. Together, our data indicate that Q203 is a promising new clinical candidate for the treatment of tuberculosis