151 research outputs found

    Development of a Nanodroplet Formulation for Triggered Release of BIO for Bone Fracture Healing

    Get PDF
    Impaired fracture healing impacts patients’ quality of life and imposes a financial burden on healthcare services. Up to 10% of bone fractures result in delayed/non-union fractures, for which new treatments are urgently required. However, systemic delivery of bone anabolic molecules is often sub-optimal and can lead to significant side effects. In this study, we developed ultrasound (US) responsive nano-sized vehicles in the form of perfluorocarbon nanodroplets (NDs), as a means of targeting delivery of drugs to localised tissues. We tested the hypothesis that NDs could stably encapsulate BIO (GSK-3β inhibitor), which could then be released upon US stimulation to activate Wnt signalling and induce ossification. NDs (~280 nm) were prepared from phospholipids and liquid perfluorocarbon and their stability and drug loading was studied by NTA (Nano Tracking Analysis) and HPLC. ND cytotoxicity was assessed in patient-derived bone marrow stromal cells (BMSCs) with Alamar Blue (24 h), and in vitro bioactivity of BIO-NDs was evaluated in a 3T3 Wnt-pathway reporter cell line with luciferase readout. To investigate the acoustic behaviour of NDs, 2% agarose (LM) containing NDs was injected into a bespoke bone fracture model (Sawbones) of various geometries and stimulated by US (1 MHz, 5% duty cycle, 1 MPa, 30 s), allowing the simultaneous capture of optical images and acoustic emissions. Femoral bone hole defects (1–2 mm) were made in WT-MF1 mice (age: 8–12 wks) and DiR-labelled NDs (100 µL, 109 NDs/mL, i.v.) were injected post-fracture to determine biodistribution by IVIS imaging. NDs were stable (4 and 37 °C) and retained >90% BIO until US was applied, which caused ~100% release. ND exposure up to a concentration of 109 NDs/mL showed no cytotoxicity (24 h). BIO-loaded NDs induced Wnt pathway activation in a dose dependent manner. Biodistribution of DiR-NDs in a femoral bone hole defect model in mice demonstrated increased localisation at the fracture site (~2-fold relative to that found in healthy mice or contralateral femurs at 48 h)

    Tailoring the size of ultrasound responsive lipid-shelled nanodroplets by varying production parameters and environmental conditions

    Get PDF
    Liquid perfluorocarbon nanodroplets (NDs) are an attractive alternative to microbubbles (MBs) for ultrasound-mediated therapeutic and diagnostic applications. ND size and size distribution have a strong influence on their behaviour in vivo, including extravasation efficiency, circulation time, and response upon ultrasound stimulation. Thus, it is desirable to identify ways to tailor the ND size and size distribution during manufacturing. In this study phospholipid-coated NDs, comprising a perfluoro-n-pentane (PFP) core stabilised by a DSPC/PEG40s (1,2-distearoyl-sn-glycero-3-phosphocholine and polyoxyethylene(40)stearate, 9:1 molar ratio) shell, were produced in phosphate-buffered saline (PBS) by sonication. The effect of the following production-related parameters on ND size was investigated: PFP concentration, power and duration of sonication, and incorporation of a lipophilic fluorescent dye. ND stability was also assessed at both 4°C and 37°C. When a sonication pulse of 6 s and 15% duty cycle was employed, increasing the volumetric concentration of PFP from 5% to 15% v/v in PBS resulted in an increase in ND diameter from 215.8 ± 16.8 nm to 408.9 ± 171.2 nm. An increase in the intensity of sonication from 48 to 72 W (with 10% PFP v/v in PBS) led to a decrease in ND size from 354.6 ± 127.2 nm to 315.0 ± 100.5 nm. Increasing the sonication time from 20 s to 40 s (using a pulsed sonication with 30% duty cycle) did not result in a significant change in ND size (in the range 278 - 314 nm); however, when it was increased to 60 s, the average ND diameter reduced to 249.7 ± 9.7 nm, which also presented a significantly lower standard deviation compared to the other experimental conditions investigated (i.e., 9.7 nm vs. > 49.4 nm). The addition of the fluorescent dye DiI at different molar ratios did not affect the ND size distribution. NDs were stable at 4°C for up to 6 days and at 37°C for up to 110 min; however, some evidence of ND-to-MB phase transition was observed after 40 min at 37°C. Finally, phase transition of NDs into MBs was demonstrated using a tissue-mimicking flow phantom under therapeutic ultrasound exposure conditions (ultrasound frequency: 0.5 MHz, acoustic pressure: 2-4 MPa, and pulse repetition frequency: 100 Hz)

    Transcatheter Aortic Valve Implantation in Severe Left Ventricular Dysfunction: A Viable Option in a Patient With Low-Flow, Low-Gradient Critical Aortic Stenosis

    Get PDF
    Images are provided from a successful procedure of transcatheter aortic valve implantation (TAVI) in an elderly patient with symptomatic low-flow, low-gradient critical aortic stenosis, and associated severe left ventricular dysfunction, who had a very high-risk for surgery

    Primary Congenital Coronary Artery Anomalies: An Angiographic Study in Greece

    Get PDF
    Abstract Background: Primary congenital coronary anomalies are anatomical variations of the origin, course and termination of coronary arteries, which are not associated with complex congenital heart disease. In Greece, apart from some case reports, there are no published data. Thus, the aim of this study was to assess the prevalence of the different forms of primary coronary artery anomalies in a Greek adult population. Methods: 5051 coronary arteriographies obtained from January 2008 to December 2010 were retrospectively analyzed. Coronary anomalies were classified according to the criteria proposed by Angelini and coworkers as anomalies of origin and course, anomalies of intrinsic coronary anatomy, and anomalies of termination. Results: 123 variations of coronary artery anatomy (incidence 2.44%) were identified. Of these, 76 (61.8%) patients had anomalous origin and course, 25 (20.3%) patients had ectasias, 14 (11.4%) patients had myocardial bridging, and 8 (6.5%) patients had small coronary fistulas. The most common anomalies observed were the separate origin of the left anterior descending (LAD) and left circumflex (LCx) coronary arteries, the ectopic right coronary artery (RCA) and the anomalous LCx from the opposite sinus. Conclusions: The incidence of primary congenital anomalies in Greece is similar to that reported in other populations. Congenital coronary anomalies do not predispose to accelerated atherosclerosis of the anomalous vessel. Although the majority of coronary anomalies were not associated with symptoms and were detected incedentaly during coronary angiography, awareness of these anatomical variants is clinically important for the appropriate management of cardiac patients

    Bisphenol A-glycidyl methacrylate induces a broad spectrum of DNA damage in human lymphocytes

    Get PDF
    Bisphenol A-glycidyl methacrylate (BisGMA) is monomer of dental filling composites, which can be released from these materials and cause adverse biologic effects in human cells. In the present work, we investigated genotoxic effect of BisGMA on human lymphocytes and human acute lymphoblastic leukemia cell line (CCRF-CEM) cells. Our results indicate that BisGMA is genotoxic for human lymphocytes. The compound induced DNA damage evaluated by the alkaline, neutral, and pH 12.1 version of the comet assay. This damage included oxidative modifications of the DNA bases, as checked by DNA repair enzymes EndoIII and Fpg, alkali-labile sites and DNA double-strand breaks. BisGMA induced DNA-strand breaks in the isolated plasmid. Lymphocytes incubated with BisGMA at 1 mM were able to remove about 50% of DNA damage during 120-min repair incubation. The monomer at 1 mM evoked a delay of the cell cycle in the S phase in CCRF-CEM cells. The experiment with spin trap—DMPO demonstrated that BisGMA induced reactive oxygen species, which were able to damage DNA. BisGMA is able to induce a broad spectrum of DNA damage including severe DNA double-strand breaks, which can be responsible for a delay of the cell cycle in the S phase

    Association between biliary complications and technique of hilar division (extrahepatic vs. intrahepatic) in major liver resections

    Get PDF
    BACKGROUND: Division of major vascular and biliary structures during major hepatectomies can be carried out either extrahepatically at the porta hepatic or intrahepatically during the parenchymal transection. In this retrospective study we test the hypothesis that the intrahepatic technique is associated with less early biliary complications. METHODS: 150 patients who underwent major hepatectomies were retrospectively allocated into an intrahepatic group (n = 100) and an extrahepatic group (n = 50) based on the technique of hilar division. The two groups were operated by two different surgical teams, each one favoring one of the two approaches for hilar dissection. Operative data (warm ischemic time, operative time, blood loss), biliary complications, morbidity and mortality rates were analyzed. RESULTS: In extrahepatic patients, operative time was longer (245 ± 50 vs 214 ± 38 min, p < 0.05) while the overall complication rate (55% vs 52%), hospital stay (13 ± 7 vs 12 ± 4 days), bile leak rate (22% vs 20%) and mortality (2% vs 2%) were similar compared to intrahepatic patients. However, most (57%) bile leaks in extrahepatic patients were grade II (leaks that required non-operative interventional treatment, while most (70%) leaks in the intrahepatic group were grade I (leaks that resolved and presented two injuries (4%) of the remaining bile ducts (p < 0.05). CONCLUSION: Intrahepatic hilar division is as safe as extrahepatic hilar division in terms of intraoperative blood requirements, morbidity and mortality. The extrahepatic technique is associated with more severe bile leaks and biliary injuries

    D1.15 Impact Assessment Report for RP 2

    Get PDF
    This deliverable provides the impact assessment report for RP2 (M16-M30). It provides an update on the overall and specific objectives of the EXCELSIOR project that have been achieved within RP2. This task undertakes the establishment of a methodology for the yearly monitoring of the impact of the different activities carried out by Eratosthenes Centre of Excellence (ECoE) and its partners through EXCELSIOR against a set of quantified targets. The list of Key Performance Indicators established in D1.12 has been revised based on the comments received by the EXCELSIOR project reviewers on 23 June 2021 following the first project review. This list is hereby updated to reflect the activities of RP2. By monitoring the impact for the RP2, it will provide direction of the activities needed to fulfil the KPIs for the following reporting periods. The impact assessment report will be used to assess the implementation of the work plan and adjust the activities in agreement with WP and task Leaders to ensure the achievement of the Project’s strategic objectives. WP1 provides the KPI monitoring framework and general quality processes, while the WP3 defines concrete actions affecting all other WPs for meeting the Impact KPIs. This task’s activities will be coordinated with WP3 activities on strategy definition as a continuous process, in order to update the human resources, infrastructure acquisition and overall work plan and to meet new priorities identified. The analysis outputs will update the Project Action Plan of Task 1.1. The following activities were examined and assessed according to the KPIs. These activities include proposals, dissemination events, publications, academia, networks, etc. The impact for each activity was also included

    Expanding the Grading of Recommendations Assessment, Development, and Evaluation (Ex-GRADE) for Evidence-Based Clinical Recommendations: Validation Study

    Get PDF
    Clinicians use general practice guidelines as a source of support for their intervention, but how much confidence should they place on these recommendations? How much confidence should patients place on these recommendations? Various instruments are available to assess the quality of evidence of research, such as the revised Wong scale (R-Wong) which examines the quality of research design, methodology and data analysis, and the revision of the assessment of multiple systematic reviews (R-AMSTAR), which examines the quality of systematic reviews

    Status Update and Interim Results from the Asymptomatic Carotid Surgery Trial-2 (ACST-2)

    Get PDF
    Objectives: ACST-2 is currently the largest trial ever conducted to compare carotid artery stenting (CAS) with carotid endarterectomy (CEA) in patients with severe asymptomatic carotid stenosis requiring revascularization. Methods: Patients are entered into ACST-2 when revascularization is felt to be clearly indicated, when CEA and CAS are both possible, but where there is substantial uncertainty as to which is most appropriate. Trial surgeons and interventionalists are expected to use their usual techniques and CE-approved devices. We report baseline characteristics and blinded combined interim results for 30-day mortality and major morbidity for 986 patients in the ongoing trial up to September 2012. Results: A total of 986 patients (687 men, 299 women), mean age 68.7 years (SD ± 8.1) were randomized equally to CEA or CAS. Most (96%) had ipsilateral stenosis of 70-99% (median 80%) with contralateral stenoses of 50-99% in 30% and contralateral occlusion in 8%. Patients were on appropriate medical treatment. For 691 patients undergoing intervention with at least 1-month follow-up and Rankin scoring at 6 months for any stroke, the overall serious cardiovascular event rate of periprocedural (within 30 days) disabling stroke, fatal myocardial infarction, and death at 30 days was 1.0%. Conclusions: Early ACST-2 results suggest contemporary carotid intervention for asymptomatic stenosis has a low risk of serious morbidity and mortality, on par with other recent trials. The trial continues to recruit, to monitor periprocedural events and all types of stroke, aiming to randomize up to 5,000 patients to determine any differential outcomes between interventions. Clinical trial: ISRCTN21144362. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved
    corecore