Nanomaterial for potential applications in biotechnology : Grafting of dendrigrafts poly-L-lysine onto polypropylene surface using plasma activation

L'immobilisation de biomacromolécules à la surface de polymères peu réactifs est une voie de synthèse de nanomatériaux qui fait actuellement l'objet de nombreuses recherches pour le développement d'applications biologiques et médicales. Nous avons synthétisé de nouveaux nanomatériaux à base de polypropylène (PP) greffé par des dendrimères de lysine (DGL). Les DGL sont parfaitement solubles dans l'eau, biocompatibles, polycationiques à pH neutre et leur structure dendritique particulière font d'eux des macromolécules de plus en plus étudiées en interactions avec les milieux biologiques. Différents traitements par plasma ont permis de fonctionnaliser la surface du PP et plusieurs stratégies ont été adoptées pour greffer les DGL sous forme de monocouche, multicouche ou à partir de brosses de polymères : le greffage direct, les polymérisations non contrôlée et contrôlée de type RAFT associées au plasma d'iode et à la chimie click de surface. L'aptitude des matériaux PP fonctionnalisés par le DGL à interagir avec les milieux biologiques a été étudiée, en particulier l'immobilisation de l'ATP et le comportement vis-à-vis des bactéries et des virus. Les propriétés de ces nanomatériaux sont liées à la réactivité des groupements amine des DGL ainsi qu'à la structure régulière et sphérique des dendrimères. Les résultats obtenus ouvrent de nombreuses applications potentielles pour le traitement des eaux, le diagnostic et la prévention du développement des micro-organismes.Great attention has been focused these last years on tailoring polymer surfaces by immobilizationof suitable molecules for biological and medical applications such as tissue engineering, drug delivery systems, antibacterial supports, and biosensors. In that context, we report the preparation of an original hybrid material based on polypropylene and poly-L-Lysine dendrigrafts (DGL) which are perfectly water soluble, and biocompatible. First, activation of the polypropylene surface (PP) was achieved using plasma treatment. Then, several strategies have been developed to graft DGL onto the PP surface such as (i) direct grafting of DGL after surface activation, (ii) the use of conventional radical polymerization or (iii) RAFT polymerization of monomers from the PP surface. The last methodology favored the increase of the DGL grafts density onto the surface. The ability of PP surface functionalized with DGL to interact with biological media was studied and the modified surfaces open the way to many potential applications in water treatment, diagnosis and prevention of the development of microorganisms

Innovative DIEP flap perfusion evaluation tool: Qualitative and quantitative analysis of indocyanine green-based fluorescence angiography with the SPY-Q proprietary software.

BackgroundPerfusion-related complications remain the most common concern in DIEP flap breast reconstruction. Indocyanine green-based fluorescence angiography can be used for the real-time intra operative assessment of flap perfusion. The SPY Elite system is the most widely used device in this setting. The main objective was to describe the use of SPY-Q proprietary software to perform qualitative and quantitative analysis of flap perfusion.MethodsThis retrospective cohort study was performed at the Curie Institute between 2013 and 2017. We included patients undergoing unilateral DIEP flap breast reconstruction for whom indocyanine green-based angiography videos were of sufficient quality for analysis. Videos were recorded with the SPY Elite System and analyzed with SPY-Q proprietary software.ResultsWe included 40 patients. We used real-time dynamic color analysis to describe three different patterns of flap perfusion. SPY-Q proprietary software provides quantitative flap perfusion parameters. Our quantitative analysis confirmed that zone I is the best perfused part of the flap and zone IV the less perfused one. There was no significant association between flap perfusion pattern and perforator anatomy, patients' clinical characteristics or postoperative outcomes. After exploratory univariate analysis, quantitative perfusion parameters were significantly impaired in young patients with diabetes mellitus or under hormone therapy by tamoxifen.ConclusionsWe here describe a new approach to assess DIEP flap perfusion using the SPY Elite System proprietary software. It provides interesting qualitative and quantitative analysis that can be used in further studies to precisely assess DIEP flap perfusion

Risk of venous thromboembolism in association with factor V leiden in cancer patients – The EDITH case-control study

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Bleeding complications during pregnancy and delivery in haemophilia carriers and their neonates in Western France: An observational study

International audienceBackground: Pregnancy, delivery and the postpartum period expose haemophilia carriers, as well as their potentially affected neonates to a high risk of haemorrhagic complications.Objectives: To describe bleeding complications in haemophilia carriers and their newborns throughout pregnancy and postpartum and to identify potential factors increasing the risk of bleeding in this population.Patients/methods: The ECHANGE multicentre observational cohort study was conducted between January 2014 and February 2019 using the BERHLINGO database comprised of patients from seven French haemophilia centres.Results: During the 5 years study period, a total of 104 haemophilia carriers and 119 neonates were included, representing 124 pregnancies and 117 deliveries. Thirty-five (30%) bleeding events were observed, most of them (83%) occurred during the postpartum period, and 37% were reported during the secondary postpartum. Neuraxial anaesthesia was not complicated by spinal haematoma. Three (2.5%) neonates experienced cerebral bleeding. Caesarean section was associated with an increased risk of maternal bleeding in primary and secondary postpartum periods. Basal factor level <0.4 IU/mL was also found to be associated with an increased risk of bleeding during secondary postpartum.Conclusion: In our cohort, bleeding events occurred in more than a third of haemophilia carriers mainly in the postpartum period, and a significant portion of this bleeding occurred during the secondary postpartum. Haemophilia carriers warrant specific attention during primary and secondary postpartum, in particular in case of caesarean section and low basal factor level. The ECHANGE study is registered at clinicaltrials.gov identifier: NCT03360149

Effect of weight-adjusted intermediate-dose versus fixed-dose prophylactic anticoagulation with low-molecular-weight heparin on venous thromboembolism among noncritically and critically ill patients with COVID-19: the COVI-DOSE trial, a multicenter, randomised, open-label, phase 4 trial

International audienceBackground: Venous thromboembolism is a major complication of coronavirus disease 2019 (COVID-19). We hypothesized that a weight-adjusted intermediate dose of anticoagulation may decrease the risk of venous thromboembolism COVID-19 patients.Methods: In this multicenter, randomised, open-label, phase 4, superiority trial with blinded adjudication of outcomes, we randomly assigned adult patients hospitalised in 20 French centers and presenting with acute respiratory SARS-CoV-2. Eligible patients were randomly assigned (1:1 ratio) to receive an intermediate weight-adjusted prophylactic dose or a fixed-dose of subcutaneous low-molecular-weight heparin during the hospital stay. The primary outcome corresponded to symptomatic deep-vein thrombosis (fatal) pulmonary embolism during hospitalization (COVI-DOSE ClinicalTrials.gov number: NCT04373707).Findings: Between May 2020, and April 2021, 1000 patients underwent randomisation in medical wards (noncritically ill) (80.1%) and intensive care units (critically ill) (19.9%); 502 patients were assigned to receive a weight-adjusted intermediate dose, and 498 received fixed-dose thromboprophylaxis. Symptomatic venous thromboembolism occurred in 6 of 502 patients (1.2%) in the weight-adjusted dose group and in 10 of 498 patients (2.1%) in the fixed-dose group (subdistribution hazard ratio, 0.59; 95% CI, 0.22-1.63; P = 0.31). There was a twofold increased risk of major or clinically relevant nonmajor bleeding: 5.9% in the weight-adjusted dose group and 3.1% in the fixed-dose group (P = 0.034).Interpretation: In the COVI-DOSE trial, the observed rate of thromboembolic events was lower than expected in patients hospitalized for COVID-19 infection, and the study was unable to show a significant difference in the risk of venous thromboembolism between the two low-molecular-weight-heparin regimens