Browsing by Author "Urzua, Marcela"

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    Interferon β-1a ring prophylaxis to reduce household transmission of SARS-CoV-2: a cluster randomised clinical trial
    (Elsevier Ltd, 2023) Castro Rodríguez, José Antonio; Fish, Eleanor; Montgomery, Samuel T.; Kollmann, Tobias R.; Iturriaga Ortiz, Carolina Alejandra; Shannon, Casey; Karpievitch, Yuliya; Ho, Joseph; Chen, Virginia; Balshaw, Robert; Ben-Othman, Rym; Aniba, Radhouane; Gidi Yunge, Francisca Andrea; Hartnell, Lucy; Hancock, David G.; Perez Mateluna, Guillermo Andrés; Urzua, Marcela; Tebbutt, Scott J.; Garcia-Huidobro, Munita Diego Nicolas; Perret, Perez Cecilia; Borzutzky Schachter, Arturo José; Stick, Stephen M.
    © 2023 The Author(s)Background: Accumulating evidence indicates that an early, robust type 1 interferon (IFN) response to SARS-CoV-2 is important in determining COVID-19 outcomes, with an inadequate IFN response associated with disease severity. Our objective was to examine the prophylactic potential of IFN administration to limit viral transmission. Methods: A cluster randomised open label clinical trial was undertaken to determine the effects of pegylated IFNβ-1a administration on SARS-CoV-2 household transmission between December 3rd, 2020 and June 29th, 2021. Index cases were identified from databases of confirmed SARS-CoV-2 individuals in Santiago, Chile. Households were cluster randomised (stratified by household size and age of index cases) to receive 3 doses of 125 μg subcutaneous pegylated IFNβ-1a (172 households, 607 participants), or standard care (169 households, 565 participants). The statistical team was blinded to treatment assignment until the analysis plan was finalised. Analyses were undertaken to determine effects of treatment on viral shedding and viral transmission. Safety analyses included incidence and severity of adverse events in all treatment eligible participants in the standard care arm, or in the treatment arm with at least one dose administered. Clinicaltrials.gov identifier: NCT04552379. Findings: 5154 index cases were assessed for eligibility, 1372 index cases invited to participate, and 341 index cases and their household contacts (n = 831) enrolled. 1172 participants in 341 households underwent randomisation, with 607 assigned to receive IFNβ-1a and 565 to standard care. Based on intention to treat (ITT) and per protocol (PP) analyses for the primary endpoints, IFNβ-1a treatment did not affect duration of viral shedding in index cases (absolute risk reduction = −0.2%, 95% CI = −8.46% to 8.06%) and transmission of SARS-CoV-2 to household contacts (absolute risk reduction = 3.87%, 95% CI = −3.6% to 11.3%). Treatment with IFNβ-1a resulted in significantly more treatment-related adverse events, but no increase in overall adverse events or serious adverse events. Interpretation: Based upon the primary analyses, IFNβ-1a treatment did not affect duration of viral shedding or the probability of SARS-CoV-2 transmission to uninfected contacts within a household. Funding: Biogen PTY Ltd. Supply of interferon as ‘Plegridy (peginterferon beta-1a).’ The study was substantially funded by BHP Holdings Pty Ltd.
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    Monolayers and Thin Films of Dextran Hydrophobically Modified
    (SOC BRASILEIRA QUIMICA, 2010) Leiva, Angel; Munoz, Natalia; Urzua, Marcela; Gargallo, Ligia; Radic, Deodato
    A series of biodegradable graft copolymers were synthesized by grafting epsilon-caprolactone over dextran of different molecular weights. The obtained copolymers were characterized by Fourier transform infrared spectroscopy FTIR, proton nuclear magnetic resonance H-1 NMR, thermogravimetry and elemental analysis. Stable monolayers at the air-water interface and spin coated thin films were prepared and characterized by the Langmuir technique and by contact angle measurements respectively. The compressibility and static surface elasticity of the monolayers and the surface energy of copolymer thin films show dependence with the epsilon-caprolactone content. From these results it can be concluded that the surface properties of grafted copolymers can be modulated by their composition. Additionally, according to the obtained results, epsilon-caprolactone grafted-dextrans show potential for being used in different applications where surface properties are important.
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    Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial
    Abarca Villaseca, Katia; Iturriaga Ortiz, Carolina Alejandra; Urzua, Marcela; Le Corre Perez, Monique Nicole; Pineda Núñez, Augusto Naim; Fernandez Anwandter, Carolina; Domínguez De Landa, María Angelica; González Carbonell, Pablo Andrés; Bueno, Susan M.; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; Gonzalez, Marcela; Guzman, Paula; Munoz-Venturelli, Paula; Perez, Carlos M.; Potin, Marcela; Rojas, Alvaro; Gonzalez-Aramundiz, Jose, V; Galvez, Nicolas M. S.; Aguirre-Boza, Francisca; Aljaro, Sofia; Federico Batiz, Luis; Campisto, Yessica; Cepeda, Mariela; Cortes, Aaron; Lopez, Sofia; Loreto Perez, Maria; Schilling, Andrea; Kalergis, Alexis M.
    Several vaccines have been developed to control the COVID-19 pandemic. CoronaVac (R), an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac (R) in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged >= 60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac (R) is safe, especially in >= 60-year-old participants. Both schedules protected against COVID-19 hospitalization.
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    Safety, Tolerability, Bioavailability, and Biological Activity of Inhaled Interferon-& alpha;2b in Healthy Adults: The (INCOVID)-C-2 Phase I Randomized Trial
    (2023) García-Huidobro Munita, Diego Nicolás; Iturriaga, Carolina; Perez-Mateluna, Guillermo; Fajuri, Paula; Severino Cuevas, Nicolás Felipe; Urzua, Marcela; Fraga, Juan Pablo; Cruz, Javiera de la; Poli, Cecilia; Castro Rodríguez, José Antonio; Fish, Eleanor; Borzutzky, Arturo
    Background and ObjectivesInterferons have been identified as a potential treatment alternative for coronavirus disease 2019. This study assessed the safety, tolerability, bioavailability, and biological activity of inhaled interferon-& alpha;2b (IFN)-& alpha;2b in healthy adults.MethodsA double-blind, randomized, phase I clinical trial was conducted with two cohorts of healthy subjects aged 18-50 years. The first cohort received 2.5 MIU of inhaled IFN-& alpha;2b twice daily for 10 days (n = 6) or placebo (n = 3); the second cohort received 5.0 MIU of inhaled IFN-& alpha;2b in a similar scheme (n = 6) or placebo (n = 3). The first two doses were administered in an emergency department, then participants completed their treatment at home. Safety was measured through vital signs, new symptoms, and laboratory tests. Tolerability was measured as participants' treatment acceptability. Bioavailability and biological activity were measured from serum IFN & alpha; concentrations and real-time quantitative polymerase chain reaction of interferon-induced genes in blood before and after treatments.ResultsExposure to inhaled IFN-& alpha;2b at 2.5-MIU or 5-MIU doses did not produce statistically significant changes in participant vital signs, or elicit new symptoms, and standard hematological and biochemical blood measurements were comparable to those recorded in individuals who received placebo. A total of 58 adverse events were observed. All were mild or moderate and did not require medical care. All participants reported very high tolerability towards a twice-daily nebulized treatment for 10 days (98.0, 97.0, and 97.0 in the placebo, 2.5-MIU, and 5-MIU groups, respectively, on a 0- to 100-mm visual analog scale). A dose-dependent mild increase in serum IFN-& alpha; concentrations and an increase in serum RNA expression of IFN-induced genes were observed 11 days after treatment (p < 0.05 for all between-group comparisons).ConclusionsInhaled IFN-& alpha;2b was preliminarily safe and well tolerated, and induced systemic biological activity in healthy subjects.
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    Spontaneous Adsorption of Gold Nanoparticles by Polyelectrolyte Thin Films
    (AMER SCIENTIFIC PUBLISHERS, 2012) Urzua, Marcela; Leiva, Angel; Espinoza Beltran, Francisco J.; Briones, Ximena; Saldias, Cesar; Pino, Maximiliano
    Nanocomposed films constituted by gold nanoparticles immobilized onto polyelectrolytes were obtained and studied. To obtain the films, amino terminated silicon wafer surfaces were put in contact with aqueous solution of polyelectrolytes derived from Poly(maleic anhydride-alt-styrene) containing aryl and amine-alkyl groups in the side chains, in this condition the adsorption of macromolecules was achieved. The effects of the chemical nature of the side chains and ionic strength on the amounts of adsorbed polyelectrolytes were studied by ellipsometry. The adsorption of polyelectrolytes increases with increasing ionic strength in agreement with the screening-enhanced adsorption regime; the results are discussed considering the steric hindrance of the side chains and flexibility of the polymers. A spontaneous adsorption process of nanoparticles onto polyelectrolyte films took place when these last were immersed in a gold nanoparticles suspension. The adsorption amounts were qualitatively evaluated by SEM and AFM and these showed to be dependent on chemical structure of polyelectrolytes.