Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects.

BACKGROUND: The long-term effects of sibutramine treatment on the rates of cardiovascular events and cardiovascular death among subjects at high cardiovascular risk have not been established. METHODS: We enrolled in our study 10,744 overweight or obese subjects, 55 years of age or older, with preexisting cardiovascular disease, type 2 diabetes mellitus, or both to assess the cardiovascular consequences of weight management with and without sibutramine in subjects at high risk for cardiovascular events. All the subjects received sibutramine in addition to participating in a weight-management program during a 6-week, single-blind, lead-in period, after which 9804 subjects underwent random assignment in a double-blind fashion to sibutramine (4906 subjects) or placebo (4898 subjects). The primary end point was the time from randomization to the first occurrence of a primary outcome event (nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, or cardiovascular death). RESULTS: The mean duration of treatment was 3.4 years. The mean weight loss during the lead-in period was 2.6 kg; after randomization, the subjects in the sibutramine group achieved and maintained further weight reduction (mean, 1.7 kg). The mean blood pressure decreased in both groups, with greater reductions in the placebo group than in the sibutramine group (mean difference, 1.2/1.4 mm Hg). The risk of a primary outcome event was 11.4% in the sibutramine group as compared with 10.0% in the placebo group (hazard ratio, 1.16; 95% confidence interval [CI], 1.03 to 1.31; P=0.02). The rates of nonfatal myocardial infarction and nonfatal stroke were 4.1% and 2.6% in the sibutramine group and 3.2% and 1.9% in the placebo group, respectively (hazard ratio for nonfatal myocardial infarction, 1.28; 95% CI, 1.04 to 1.57; P=0.02; hazard ratio for nonfatal stroke, 1.36; 95% CI, 1.04 to 1.77; P=0.03). The rates of cardiovascular death and death from any cause were not increased. CONCLUSIONS: Subjects with preexisting cardiovascular conditions who were receiving long-term sibutramine treatment had an increased risk of nonfatal myocardial infarction and nonfatal stroke but not of cardiovascular death or death from any cause. (Funded by Abbott; ClinicalTrials.gov number, NCT00234832.

RP-HPLC METHOD WITH UV DETECTION FOR THE EVALUATION OF CHITOSAN-GRAFT-Β-CYCLODEXTRIN/PVA HYDROGELS AS CARRIERS FOR THE CONTROLLED RELEASE OF VEMURAFENIB

When developing a topical formulation, it is essential to evaluate it from the perspective of its carrier capacity for the controlled release of the encapsulated drug. The drug should be simply quantified through an accurate and reproducible method. This paper presents a rapid, simple, sensitive, and reproducible high-performance liquid chromatography method with UV detection for evaluating the ability of chitosan-graft-(3-cyclodextrin/PVA (CS-g-(3-CD/PVA) hydrogels as carriers for the controlled release of vemurafenib (VEM). Materials and methods: The chromatographic separation was achieved using a Waters CORTECS C18 column (100 x 2.1 mm ID, 2.7 mu m). The mobile phase was a mixture of: A (water/formic acid-99.9/0.1, v/v), B (acetonitrile), and C (methanol) in the ratio of 40: 55: 5 (v/v/v). The injection sample amount was 10 mu L, and the run time was 9 minutes in isocratic mode at a flow rate of 1 mL/min. The analyte was detected using UV absorption at 252 nm. Results: The standard calibration curve was linear over the concentration range of 0.78-100 mg/L. The values for LOD and LOQ were 0.5 mg/L and 0.75 mg/L, respectively. The intra-and inter-day precision of measurements were lower than the accepted criteria (RSD <= 2%). The high value of recoveries obtained for VEM indicates that the proposed method was found to be accurate. The stability of VEM solutions was assessed, indicating that the drug remained stable under all relevant conditions. Conclusions: Finally, the validated method was successfully applied to evaluate the ability of chitosan-graft-(3-cyclodextrin/PVA hydrogels to load and sustain release of VEM. The drug entrapment efficiency (DEE%) was between 65 +/- 0.08% and 70 +/- 0.05%

Liraglutide once a day versus exenatide twice a day for type 2 diabetes: a 26-week randomised, parallel-group, multinational, open-label trial (LEAD-6)

BACKGROUND: Unlike most antihyperglycaemic drugs, glucagon-like peptide-1 (GLP-1) receptor agonists have a glucose-dependent action and promote weight loss. We compared the efficacy and safety of liraglutide, a human GLP-1 analogue, with exenatide, an exendin-based GLP-1 receptor agonist. METHODS: Adults with inadequately controlled type 2 diabetes on maximally tolerated doses of metformin, sulphonylurea, or both, were stratified by previous oral antidiabetic therapy and randomly assigned to receive additional liraglutide 1.8 mg once a day (n=233) or exenatide 10 microg twice a day (n=231) in a 26-week open-label, parallel-group, multinational (15 countries) study. The primary outcome was change in glycosylated haemoglobin (HbA(1c)). Efficacy analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00518882. FINDINGS: Mean baseline HbA(1c) for the study population was 8.2%. Liraglutide reduced mean HbA(1c) significantly more than did exenatide (-1.12% [SE 0.08] vs -0.79% [0.08]; estimated treatment difference -0.33; 95% CI -0.47 to -0.18; p<0.0001) and more patients achieved a HbA(1c) value of less than 7% (54%vs 43%, respectively; odds ratio 2.02; 95% CI 1.31 to 3.11; p=0.0015). Liraglutide reduced mean fasting plasma glucose more than did exenatide (-1.61 mmol/L [SE 0.20] vs -0.60 mmol/L [0.20]; estimated treatment difference -1.01 mmol/L; 95% CI -1.37 to -0.65; p<0.0001) but postprandial glucose control was less effective after breakfast and dinner. Both drugs promoted similar weight losses (liraglutide -3.24 kg vs exenatide -2.87 kg). Both drugs were well tolerated, but nausea was less persistent (estimated treatment rate ratio 0.448, p<0.0001) and minor hypoglycaemia less frequent with liraglutide than with exenatide (1.93 vs 2.60 events per patient per year; rate ratio 0.55; 95% CI 0.34 to 0.88; p=0.0131; 25.5%vs 33.6% had minor hypoglycaemia). Two patients taking both exenatide and a sulphonylurea had a major hypoglycaemic episode. INTERPRETATION: Liraglutide once a day provided significantly greater improvements in glycaemic control than did exenatide twice a day, and was generally better tolerated. The results suggest that liraglutide might be a treatment option for type 2 diabetes, especially when weight loss and risk of hypoglycaemia are major considerations

Edoxaban versus warfarin in patients with atrial fibrillation

Contains fulltext : 125374.pdf (publisher's version ) (Open Access)BACKGROUND: Edoxaban is a direct oral factor Xa inhibitor with proven antithrombotic effects. The long-term efficacy and safety of edoxaban as compared with warfarin in patients with atrial fibrillation is not known. METHODS: We conducted a randomized, double-blind, double-dummy trial comparing two once-daily regimens of edoxaban with warfarin in 21,105 patients with moderate-to-high-risk atrial fibrillation (median follow-up, 2.8 years). The primary efficacy end point was stroke or systemic embolism. Each edoxaban regimen was tested for noninferiority to warfarin during the treatment period. The principal safety end point was major bleeding. RESULTS: The annualized rate of the primary end point during treatment was 1.50% with warfarin (median time in the therapeutic range, 68.4%), as compared with 1.18% with high-dose edoxaban (hazard ratio, 0.79; 97.5% confidence interval [CI], 0.63 to 0.99; P<0.001 for noninferiority) and 1.61% with low-dose edoxaban (hazard ratio, 1.07; 97.5% CI, 0.87 to 1.31; P=0.005 for noninferiority). In the intention-to-treat analysis, there was a trend favoring high-dose edoxaban versus warfarin (hazard ratio, 0.87; 97.5% CI, 0.73 to 1.04; P=0.08) and an unfavorable trend with low-dose edoxaban versus warfarin (hazard ratio, 1.13; 97.5% CI, 0.96 to 1.34; P=0.10). The annualized rate of major bleeding was 3.43% with warfarin versus 2.75% with high-dose edoxaban (hazard ratio, 0.80; 95% CI, 0.71 to 0.91; P<0.001) and 1.61% with low-dose edoxaban (hazard ratio, 0.47; 95% CI, 0.41 to 0.55; P<0.001). The corresponding annualized rates of death from cardiovascular causes were 3.17% versus 2.74% (hazard ratio, 0.86; 95% CI, 0.77 to 0.97; P=0.01), and 2.71% (hazard ratio, 0.85; 95% CI, 0.76 to 0.96; P=0.008), and the corresponding rates of the key secondary end point (a composite of stroke, systemic embolism, or death from cardiovascular causes) were 4.43% versus 3.85% (hazard ratio, 0.87; 95% CI, 0.78 to 0.96; P=0.005), and 4.23% (hazard ratio, 0.95; 95% CI, 0.86 to 1.05; P=0.32). CONCLUSIONS: Both once-daily regimens of edoxaban were noninferior to warfarin with respect to the prevention of stroke or systemic embolism and were associated with significantly lower rates of bleeding and death from cardiovascular causes. (Funded by Daiichi Sankyo Pharma Development; ENGAGE AF-TIMI 48 ClinicalTrials.gov number, NCT00781391.)

Stroke and Mortality Risk in Patients With Various Patterns of Atrial Fibrillation Results From the ENGAGE AF-TIMI 48 Trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48)

Background-Whether the pattern of atrial fibrillation (AF) modifies the risk/benefit of anticoagulation is controversial. In ENGAGE AF-TIMI 48 trial (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48), the factor Xa inhibitor edoxaban was noninferior to warfarin in preventing stroke or systemic embolic events and significantly reduced bleeding and cardiovascular mortality. However, detailed analyses by AF pattern have not been reported.Methods and Results-The 21 105 patients were categorized as having paroxysmal (= 7 days but = 1 year or failed cardioversion) AF patterns at randomization. Efficacy and safety outcomes were evaluated during the 2.8 years median follow-up and compared by AF pattern. The primary end point of stroke/systemic embolic event was lower in those patients with paroxysmal AF (1.49%/year), compared with persistent (1.83%/year; P-adj =0.015) and permanent AF (1.95%/year; P-adj =0.004). Overall, all-cause mortality also was lower with paroxysmal (3.0%/year) compared with persistent (4.4%/year; P-adj <0.001) and permanent AF (4.4%/year; P-adj <0.001). Annualized major bleeding rates were similar across AF patterns (2.86% versus 2.65% versus 2.73%). There was no effect modification by treatment assignment.Conclusions-In ENGAGE AF-TIMI 48 trial, patients with paroxysmal AF suffered fewer thromboembolic events and deaths compared with those with persistent and permanent AF. The efficacy and safety profile of edoxaban as compared with warfarin was consistent across the 3 patterns of AF.Daiichi-Sankyo Pharma In

Cerebrovascular Events in 21 105 Patients With Atrial Fibrillation Randomized to Edoxaban Versus Warfarin Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48

Background and Purpose-The once-daily oral factor Xa inhibitor, edoxaban, is as effective as warfarin in preventing stroke and systemic embolism while decreasing bleeding in a phase III trial of patients with atrial fibrillation at moderate-high stroke risk. Limited data regarding cerebrovascular events with edoxaban were reported previously.Methods-We analyzed the subtypes of cerebrovascular events in 21 105 patients participating in Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48 (ENGAGE AF-TIMI 48) comparing outcomes among patients randomized to warfarin versus 2 edoxaban regimens (high dose, low dose). The primary end point for this prespecified analysis of cerebrovascular events was all stroke (ischemic plus hemorrhagic), defined as an abrupt onset of focal neurological deficit because of infarction or bleeding with symptoms lasting >= 24 hours or fatal in < 24 hours. Independent stroke neurologists unaware of treatment adjudicated all cerebrovascular events.Results-Patients randomized to high-dose edoxaban had fewer strokes on-treatment (hazard ratio, 0.80; 95% confidence interval, 0.65-0.98) than warfarin (median time-in-therapeutic range, 68.4%); patients in the low-dose edoxaban group had similar rates (hazard ratio, 1.10 versus warfarin; 95% confidence interval, 0.91-1.32). Rates of ischemic stroke or transient ischemic attack were similar with high-dose edoxaban (1.76% per year) and warfarin (1.73% per year; P= 0.81), but more frequent with low-dose edoxaban (2.48% per year; P< 0.001). Both edoxaban regimens significantly reduced hemorrhagic stroke and other subtypes of intracranial bleeds.Conclusions-In patients with atrial fibrillation, once-daily edoxaban was as effective as warfarin in preventing all strokes, with significant reductions in various subtypes of intracranial bleeding. Ischemic cerebrovascular event rates were similar with high-dose edoxaban and warfarin, whereas low-dose edoxaban was less effective than warfarin.Daiichi Sankyo Pharma Developmen