24 research outputs found
Manufacturing of hybrid drug delivery systems by utilizing the fused filament fabrication (FFF) technology
Inter-annual trends of ultrafine particles in urban Europe
Ultrafine particles (UFP, those with diameters ≤ 100 nm), have been reported to potentially penetrate deeply into the respiratory system, translocate through the alveoli, and affect various organs, potentially correlating with increased mortality. The aim of this study is to assess long-term trends (5–11 years) in mostly urban UFP concentrations based on measurements of particle number size distributions (PNSD). Additionally, concentrations of other pollutants and meteorological variables were evaluated to support the interpretations. PNSD datasets from 12 urban background (UB), 5 traffic (TR), 3 suburban background (SUB) and 1 regional background (RB) sites in 15 European cities and 1 in the USA were evaluated. The non-parametric Theil-Sen's method was used to detect monotonic trends. Meta-analyses were carried out to assess the overall trends and those for different environments. The results showed significant decreases in NO, NO2, BC, CO, and particle concentrations in the Aitken (25–100 nm) and the Accumulation (100–800 nm) modes, suggesting a positive impact of the implementation of EURO 5/V and 6/VI vehicle standards on European air quality. The growing use of Diesel Particle Filters (DPFs) might also have clearly reduced exhaust emissions of BC, PM, and the Aitken and Accumulation mode particles. However, as reported by prior studies, there remains an issue of poor control of Nucleation mode particles (smaller than 25 nm), which are not fully reduced with current DPFs, without emission controls for semi-volatile organic compounds, and might have different origins than road traffic. Thus, contrasting trends for Nucleation mode particles were obtained across the cities studied. This mode also affected the UFP and total PNC trends because of the high proportion of Nucleation mode particles in both concentration ranges. It was also found that the urban temperature increasing trends might have also influenced those of PNC, Nucleation and Aitken modes.</p
Results of the first European Source Apportionment intercomparison for Receptor and Chemical Transport Models
In this study, the performance of the source apportionment model applications were evaluated by comparing the model results provided by 44 participants adopting a methodology based on performance indicators: z-scores and RMSEu, with pre-established acceptability criteria. Involving models based on completely different and independent input data, such as receptor models (RMs) and chemical transport models (CTMs), provided a unique opportunity to cross-validate them. In addition, comparing the modelled source chemical profiles, with those measured directly at the source contributed to corroborate the chemical profile of the tested model results. The most used RM was EPA- PMF5. RMs showed very good performance for the overall dataset (91% of z-scores accepted) and more difficulties are observed with SCE time series (72% of RMSEu accepted). Industry resulted the most problematic source for RMs due to the high variability among participants. Also the results obtained with CTMs were quite comparable to their ensemble reference using all models for the overall average (>92% of successful z-scores) while the comparability of the time series is more problematic (between 58% and 77% of the candidates’ RMSEu are accepted). In the CTM models a gap was observed between the sum of source contributions and the gravimetric PM10 mass likely due to PM underestimation in the base case. Interestingly, when only the tagged species CTM results were used in the reference, the differences between the two CTM approaches (brute force and tagged species) were evident. In this case the percentage of candidates passing the z-score and RMSEu tests were only 50% and 86%, respectively. CTMs showed good comparability with RMs for the overall dataset (83% of the z-scores accepted), more differences were observed when dealing with the time series of the single source categories. In this case the share of successful RMSEu was in the range 25% - 34%.JRC.C.5-Air and Climat
In Vitro Evaluation of 2D-Printed Edible Films for the Buccal Delivery of Diclofenac Sodium
Printing technologies have recently emerged in the development of novel drug delivery systems toward personalized medicine, to improve the performance of formulations, existing bioavailability patterns, and patients’ compliance. In the context of two-dimensional printing, this article presents the development of buccal films that are designed to efficiently deliver a class II compound (diclofenac sodium), according to the Biopharmaceutics Classification System (BCS), to the oral cavity. The preparation of drug-loaded inks was carried out based on solubility studies and evaluation of rheological properties, combining ethanol and propylene glycol as optimal solvents. Deposition of the drug was achieved by increasing the number of printing layers onto edible substrates, to produce formulations with dose variance. Thermal analysis, X-ray diffraction, and infrared spectroscopy were used to characterize the developed films. Drug loading and water uptake studies complemented the initial assessment of the films, and preliminary in vitro studies were conducted to further evaluate their performance. The in vitro release profiles were recorded in simulated saliva, presenting the complete release of the incorporated active in a period of 10 min. The effect of multiple layers on the overall performance of films was completed with in vitro permeation studies, revealing the correlation between the number of printed layers and the apparent permeability coefficient
Correction: Andreadis et al. The Advent of a New Era in Digital Healthcare: A Role for 3D Printing Technologies in Drug Manufacturing? <i>Pharmaceutics</i> <b>2022</b>, <i>14</i>, 609
In the original publication [...
Plasma Indoleamine 2,3-Dioxygenase and Arginase Type I May Contribute to Decreased Blood T-Cell Count in Hemodialysis Patients
Background: Acquired immunity is impaired in hemodialysis (HD) patients, and decreased T-cell number may contribute. Indoleamine 2,3-dioxygenase (IDO) and arginase type I (ARG) catabolize tryptophane and arginine, respectively, and exert proapoptotic and antiproliferative effects on T-cells. Plasma levels of IDO and ARG and their relation to blood T-cell number were evaluated in HD patients. Methods: Thirty-two HD patients and 20 healthy controls participated in the study. Plasma IDO and ARG were measured by means of enzyme-linked immunosorbent assay. T-cell number was assessed by means of flow cytometry. Results: IDO concentration was significantly higher in HD patients than in healthy volunteers (44.30 +/- 31.83 ng/mL vs. 21.28 +/- 26.21 ng/mL, p = 0.009). There was a trend for higher ARG concentration in HD patients (13.43 +/- 11.91 ng/mL) than in healthy volunteers (9.56 +/- 4.03 ng/mL), which, however, did not reach statistic significance (p = 0.099). Absolute T-cell count was significantly lower in HD patients than in healthy controls (1176.99 +/- 567.71 cells/mm(3) vs. 1519.85 +/- 594.96 cells/mm(3), p = 0.040). Absolute blood T-cell number was inversely related to plasma IDO (r = -0.490, p = 0.004) and to plasma ARG (r = -0.387, p = 0.029) concentrations. Conclusions: Plasma IDO and ARG may contribute to decreased blood T-cell count in HD patients