RESUMO
Several vaccines against COVID-19 use a recombinant SARS-CoV-2 receptor-binding domain (RBD) as antigen, making the purification of this protein a key step in their production. In this work, citrate-coated magnetic iron oxide nanoparticles were evaluated as nano adsorbents in the first step (capture) of the purification of recombinant RBD. The nanoparticles were isolated through coprecipitation and subsequently coated with sodium citrate. The citrate-coated nanoparticles exhibited a diameter of 10 ± 2 nm, a hydrodynamic diameter of 160 ± 3 nm, and contained 1.9 wt% of citrate. The presence of citrate on the nanoparticles' surface was confirmed through FT-IR spectra and thermogravimetric analysis. The crystallite size (10.1 nm) and the lattice parameter (8.3646 Å) were determined by X-ray diffraction. In parallel, RBD-containing supernatant extracted from cell culture was exchanged through ultrafiltration and diafiltration into the adsorption buffer. The magnetic capture was then optimized using different concentrations of nanoparticles in the purified supernatant, and we found 40 mg mL-1 to be optimal. The ideal amount of nanoparticles was assessed by varying the RBD concentration in the supernatant (between 0.113 mg mL-1 and 0.98 mg mL-1), which resulted in good capture yields (between 83 ± 5% and 94 ± 4%). The improvement of RBD purity after desorption was demonstrated by SDS-PAGE and RP-HPLC. Furthermore, the magnetic capture was scaled up 100 times, and the desorption was subjected to chromatographic purifications. The obtained products recognized anti-RBD antibodies and bound the ACE2 receptor, proving their functionality after the developed procedure.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Vacinas contra COVID-19 , Ácido Cítrico , Espectroscopia de Infravermelho com Transformada de Fourier , CitratosRESUMO
Fundamento: la superación profesional tiene como objetivo la formación permanente y la actualización sistemática de los graduados universitarios, el perfeccionamiento del desempeño de sus actividades profesionales y académicas, así como el enriquecimiento de su acervo cultural. Objetivo: caracterizar el comportamiento progresivo de la superación profesional en la Universidad de Ciencias Médicas de Villa Clara en el curso académico 2013-2014, con respecto al 2012-2013. Métodos: se realizó un estudio descriptivo transversal en el que se utilizaron métodos teóricos y empíricos, estos últimos se basaron principalmente en la revisión de las bases de datos de superación profesional de la Dirección de Posgrado; con la información obtenida se realizó el análisis estadístico, para lo cual se utilizaron las frecuencias absolutas y porcentaje. Resultados: en el período analizado predominaron los cursos y talleres como las modalidades más utilizadas; los temas generales fueron estrategias para el análisis de situación de salud, la superación vinculada a los nuevos servicios y tecnologías y otros de formación general integral. El mayor número de incremento en actividades y participantes corresponde al Programa de Enfermedades Transmisibles; el segundo lugar, al de Atención Materno Infantil, le siguen las Enfermedades Crónicas No Transmisibles, el Programa de Atención al Adulto Mayor y el de Suicidio. Todos ellos responden a necesidades expresadas en el cuadro de salud de la provincia. Conclusiones: en la mayoría de los programas de salud se produjeron incrementos considerables en actividades y participantes, lo cual permite aseverar el estado progresivo de la superación profesional en Villa Clara, ocurrido entre 2012-2014.
Background: the professional upgrading has as objective the steady formation and the systematic updating of the graduate university students, the improvement of performance in their professional and academic activities, as well as the enrichment of their cultural background. Objective: to characterize the progressive behavior of the professional upgrading in Villa Clara University of Medical Sciences in the academic year 2013-2014, in respect to 2012-2013. Methods: it was carried out a cross-sectional descriptive study in which theoretical and empiric methods were used, these last ones were mainly based on the review of the databases of professional upgrading of the Post graduate Direction; the statistical analysis with the obtained information was carried out, the absolute frequencies and percentage were used for that purpose. Results: courses and workshops were the predominant modalities in the analyzed period; the general topics were strategies for the analysis of health picture, the upgrading linked to the new services and technologies and others of comprehensive general formation. The biggest increment in activities and participants corresponds to the Program of Transmissible diseases; in the second place, the Infant- Maternity Attention Program, then, non Transmissible Chronic diseases, the Elderly People Attention Program and that of Suicide. All of them respond to necessities expressed in the health picture of the province. Conclusions: considerable increments in activities and participants took place in most of the health programs; it represents a progressive state of the professional upgrading in Villa Clara, from 2012 to 2014.