Investigación y Docencia con Tecnologías Antes y Durante la Pandemia en la Universidad Nacional de Luján

En este artículo situamos la perspectiva crítica de la Tecnología Educativa a través de dos ejemplos desarrollados en la Universidad Nacional de Luján (UNLu) de la República Argentina: un caso de investigación y uno de docencia. La integración analítica de estas dos actividades constituye una suerte de testimonio de cómo se desarrollaron las acciones universitarias en el contexto atípico de la pandemia, con sus luces, sombras y posibles legados

Quality Assessment of Virus-Like Particles at Single Particle Level : A Comparative Study

Virus-like particles (VLPs) have emerged as a powerful scaffold for antigen presentation and delivery strategies. Compared to single protein-based therapeutics, quality assessment requires a higher degree of refinement due to the structure of VLPs and their similar properties to extracellular vesicles (EVs). Advances in the field of nanotechnology with single particle and high-resolution analysis techniques provide appealing approaches to VLP characterization. In this study, six different biophysical methods have been assessed for the characterization of HIV-1-based VLPs produced in mammalian and insect cell platforms. Sample preparation and equipment set-up were optimized for the six strategies evaluated. Electron Microscopy (EM) disclosed the presence of several types of EVs within VLP preparations and cryogenic transmission electron microscopy (cryo-TEM) resulted in the best technique to resolve the VLP ultrastructure. The use of super-resolution fluorescence microscopy (SRFM), nanoparticle tracking analysis (NTA) and flow virometry enabled the high throughput quantification of VLPs. Interestingly, differences in the determination of nanoparticle concentration were observed between techniques. Moreover, NTA and flow virometry allowed the quantification of both EVs and VLPs within the same experiment while analyzing particle size distribution (PSD), simultaneously. These results provide new insights into the use of different analytical tools to monitor the production of nanoparticle-based biologicals and their associated contaminants

At-line multi-angle light scattering detector for faster process development in enveloped virus-like particle purification

At-line static light scattering and fluorescence monitoring allows direct in-process tracking of fluorescent virus-like particles. We have demonstrated this by coupling at-line multi-angle light scattering and fluorescence detectors to the downstream processing of enveloped virus-like particles. Since light scattering intensity is directly proportional to particle concentration, our strategy allowed a swift identification of product containing fractions and rapid process development. Virus-like particles containing the Human Immunodeficiency Virus-1 Gag protein fused to the Green Fluorescence protein were produced in Human Embryonic Kidney 293 cells by transient transfection. A single-column anion-exchange chromatography method was used for direct capture and purification. The majority of host-cell protein impurities passed through the column without binding. Virus-like particles bound to the column were eluted by linear or step salt gradients. Particles recovered in the step gradient purification were characterized by nanoparticle tracking analysis, size exclusion chromatography coupled to multi-angle light scattering and fluorescence detectors and transmission electron microscopy. A total recovery of 66% for the fluorescent particles was obtained with a 50% yield in the main product peak. Virus-like particles were concentrated 17-fold to final a concentration of 4.45 × 10 particles/mL. Simple buffers and operation make this process suitable for large scale purposes

Identification of HIV-1-Based Virus-like Particles by Multifrequency Atomic Force Microscopy

Virus-like particles (VLPs) have become a promising platform for vaccine production. VLPs are formed by structural viral proteins that inherently self-assemble when expressed in a host cell. They represent a highly immunogenic and safe vaccine platform, due to the absence of the viral genome and its high protein density. One of the most important parameters in vaccine production is the quality of the product. A related bottleneck in VLP-based products is the presence of cellular vesicles as a major contaminant in the preparations, which will require the set up of techniques allowing for specific discrimination of VLPs from host vesicular bodies. In this work novel, to our knowledge, multifrequency (MF) atomic force microscopy (AFM) has permitted full structural nanophysical characterization by its access to the virus capsid of the HIV-based VLPs. The assessment of these particles by advanced amplitude modulation-frequency modulation (AM-FM) viscoelastic mapping mode has enhanced the imaging resolution of their nanomechanical properties, opening a new window for the study of the biophysical attributes of VLPs. Finally, the identification and differentiation of HIV-based VLPs from cellular vesicles has been performed under ambient conditions, providing, to our knowledge, novel methodology for the monitoring and quality control of VLPs

At-line multi-angle light scattering detector for faster process development in enveloped virus-like particle purification

At-line static light scattering and fluorescence monitoring allows direct in-process tracking of fluorescent virus-like particles. We have demonstrated this by coupling at-line multi-angle light scattering and fluorescence detectors to the downstream processing of enveloped virus-like particles. Since light scattering intensity is directly proportional to particle concentration, our strategy allowed a swift identification of product containing fractions and rapid process development. Virus-like particles containing the Human Immunodeficiency Virus-1 Gag protein fused to the Green Fluorescence protein were produced in Human Embryonic Kidney 293 cells by transient transfection. A single-column anion-exchange chromatography method was used for direct capture and purification. The majority of host-cell protein impurities passed through the column without binding. Virus-like particles bound to the column were eluted by linear or step salt gradients. Particles recovered in the step gradient purification were characterized by nanoparticle tracking analysis, size exclusion chromatography coupled to multi-angle light scattering and fluorescence detectors and transmission electron microscopy. A total recovery of 66% for the fluorescent particles was obtained with a 50% yield in the main product peak. Virus-like particles were concentrated 17-fold to final a concentration of 4.45 × 10 particles/mL. Simple buffers and operation make this process suitable for large scale purposes

Prevalence of ethical dilemmas in advanced cancer patients (secondary analysis of the PALCOM study)

Purpose: The main aim of this study was to determine the prevalence of ethical dilemmas in the end-of-life process in advanced cancer patients. Methods: We carried out a multicenter, cross-sectional, observational, prospective study in a cohort of cancer patients whose life expectancy was ≤ 6 months. We recorded sociodemographic characteristics, diagnosis of cancer, symptom burden, cognitive and functional status, emotional impact, and sociofamilial risk factors. The main outcome measure was the detection of ethical dilemmas, based on the following definition: conflict in decision-making during the end-of-life process that involves the need to choose between morally acceptable opposing options, where none is clearly preferable to another. Results: We included 324 patients (mean age, 69 years; 58% men). We identified 117 dilemmas in 90 patients (27.8%). The dilemmas detected were as follows: (a) conflicts of information (adaptive denial, conspiracy of silence, information exceeding patient's desired limit), 15.7%; (b) discrepancies in proportionality (discussion on futility, rejection of treatment, withdrawal of life support measures), 16.7%; (c) unrealistic expectations about the outcome of clinical trials, 2.5%; and (d) request for euthanasia or medically assisted suicide, 1.2%. We observed a greater prevalence of ethical dilemmas in men, in patients receiving active cancer treatment, and in patients with emotional distress (p < 0.05). Conclusions: The prevalence of ethical dilemmas during the end-of-life process in cancer patients is relevant. Most dilemmas were associated directly or indirectly with respect for patient autonomy. In this context, the communication skills of the health professionals and advanced care planning take on a key role