Conjugation of cell-penetrating peptides with poly(Lactic-co-glycolic acid)-polyethylene glycol nanoparticles improves ocular drug delivery

In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)- polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavail- ability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG- peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confrmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flur- biprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory effcacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment effciency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective preven- tion of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen’s egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.This work was supported by the Cooperation Research Program CSIC-CITMA and a project (MAT2011-26994) funded by the Spanish Ministry of Science and Technology. AV is a recipient of a PhD grant from the CSIC. The authors thank Nacho Pérez of the IQAC-CSIC for performing the cytotoxicity assays.Peer reviewe

Bio-plastic polymers from renewable sources = Bio-plásticos de polímeros a partir de fuentes renovables

Biopolymers are useful in the industry due to its elastic properties and sustainability as replacements of non-renewable polymers. In this article, bioplastics were produced and characterized using chitosan (CH), sodium alginate (SA), and galactomannan (GAL) from insects (Hermetia illucens), brown algae (Macrocystis pyrifera) and seeds (Leucaena leucocephala), respectively. The structure of biopolymers was observed by infrared spectroscopy (FTIR) and characterized by viscosity at different concentrations. The developed bioplastics were characterized by color and mechanical properties (texture). The results were compared to standard samples (commercial). The FTIR spectra confirmed the presence of the typical structure (footprint) for the obtained polymers. The SA showed significantly higher viscosity for all concentrations compared to the standard and the other polymers. The bioplastics strength was similar among CH, SA and GAL for all concentrations; only SA (0,5%) demonstrated higher strength than the standard. For color measurements, hue value indicated a red-yellowish color and the chrome increased directly proportional with polymer concentration. The observed properties suggest that these sustainable sources might be an alternative to bioplastic production, which can be extended to functionalization and molecular interactions for broad applications in different industries

Decontamination of filtering facepiece respirators using a low-temperature-steam–2%-formaldehyde sterilization process during a pandemic: a safe alternative for re-use

Background The coronavirus disease 2019 pandemic has caused problems with respirator supplies. Re-use may minimize the impact of the shortage, but requires the availability of an efficient and safe decontamination method. Aim To determine whether low-temperature-steam–2%-formaldehyde (LTSF) sterilization is effective, preserves the properties of filtering facepiece (FFP) respirators and allows safe re-use. Methods Fourteen unused FFP2, FFP3 and N95 respirator models were subjected to two cycles of decontamination cycles. After the second cycle, each model was inspected visually and accumulated residual formaldehyde levels were analysed according to EN 14180. After one and two decontamination cycles, the fit factor (FF) of each model was tested, and penetration tests with sodium chloride aerosols were performed on five models. Findings Decontamination physically altered three of the 14 models. All of the residual formaldehyde values were below the permissible threshold. Irregular decreases and increases in FF were observed after each decontamination cycle. In the sodium chloride aerosol penetration test, three models obtained equivalent or superior results to those of the FFP classification with which they were marketed, both at baseline and after one and two cycles of decontamination, and two models had lower filtering capacity. Conclusion One and two decontamination cycles using LTSF did not alter the structure of most (11/14) respirators tested, and did not degrade the fit or filtration capacity of any of the analysed respirators. The residual formaldehyde levels complied with EN 14180. This reprocessing method could be used in times of shortage of personal protective equipment

Virtualization of assessment instruments for activities outside the classroom: questionnaires en route during visits to companies in the chemical sector

En el proyecto desarrollado se ha buscado la implementación de herramientas m-learning que permitan la virtualización del proceso de evaluación de las competencias adquiridas por los estudiantes de Grado en las actividades realizadas fuera del aula, específicamente, visitas a empresas del sector químico. Gracias a este proyecto se ha pretendido sustituir la herramienta habitual de evaluación para este tipo de actividad (redacción de una memoria) por un instrumento interactivo tipo aplicación móvil –smartphones o tablets-. Esta virtualización permite al estudiante completar una evaluación tipo test una vez finalizada la actividad docente, aprovechando el tiempo del desplazamiento desde la planta industrial visitada hasta el punto de origen. Dos aplicaciones informáticas han sido evaluadas como soporte de las potenciales herramientas de evaluación (Kahoot y iSpringSuite), logrando alcanzar los objetivos propuestos en el proyecto.In the developed project, the implementation of m-learning tools that allow the virtualization of the evaluation process of the competences acquired by the students of Degree in the activities carried out outside the classroom, specifically, visits to companies in the chemical sector. Thanks to this project, it has been tried to replace the usual evaluation tool for this type of activity (writing a report) with an interactive instrument such as a mobile application -smartphones or tablets-. This virtualization allows the student to complete a test type evaluation once the teaching activity has finished, taking advantage of the time of the trip from the industrial plant visited to the point of origin. Two computer applications have been evaluated as support for the potential assessment tools (Kahoot and iSpringSuite), achieving the objectives proposed in the project

Dynamic arrest in charged colloidal systems exhibiting large-scale structural heterogeneities

Suspensions of charged liposomes are found to exhibit typical features of strongly repulsive fluid systems at short length scales, while exhibiting structural heterogeneities at larger length scales that are characteristic of attractive systems. We model the static structure factor of these systems using effective pair interaction potentials composed of a long-range attraction and a shorter range repulsion. Our modeling of the static structure yields conditions for dynamically arrested states at larger volume fractions, which we find to agree with the experimentally observed dynamics

The synovial and blood monocyte DNA methylomes mirror prognosis, evolution and treatment in early arthritis

Identifying predictive biomarkers at early stages of early inflammatory arthritis is crucial for starting appropriate therapies to avoid poor outcomes. Monocytes and macrophages, largely associated with arthritis, are contributors and sensors of inflammation through epigenetic modifications. In this study, we investigated associations between clinical features and DNA methylation in blood and synovial fluid (SF) monocytes in a prospective cohort of early inflammatory arthritis patients. Undifferentiated arthritis (UA) blood monocyte DNA methylation profiles exhibited significant alterations in comparison with those from healthy donors. We identified additional differences both in blood and SF monocytes after comparing UA patients grouped by their future outcomes, good versus poor. Patient profiles in subsequent visits revealed a reversion towards a healthy level in both groups, those requiring disease-modifying antirheumatic drugs (DMARDs) and those that remitted spontaneously. Changes in disease activity between visits also impacted DNA methylation, partially concomitant in the SF of UA and in blood monocytes of rheumatoid arthritis patients. Epigenetic similarities between arthritis types allow a common prediction of disease activity. Our results constitute a resource of DNA methylation-based biomarkers of poor prognosis, disease activity and treatment efficacy in early untreated UA patients for the personalized clinical management of early inflammatory arthritis patients

The potential association of later initiation of oral/enteral nutrition on euthyroid sick syndrome in burn patients.

Objective. e aim of this study was to determine if early initiation of oral/enteral nutrition in burn patients minimizes the drop in fT3 levels, reduces the potential for euthyroid sick syndrome (ESS), and shortens the length of hospital stay (LHS). Subjects and Methods. We retrospectively evaluated the statistical association of serum fT3, fT4, and TSH at the �rst (2nd-5th day) and second sample collection (9th-12th day) aer the burn injury in 152 burn patients. ree groups were established depending on time of initiation of the oral/enteral nutrition: <24 h before the injury (Group 1), 24-48 h aer the injury (Group 2), and >48 h aer the injury (Group 3). Results. ey were expressed as mean ± standard deviation. We found that LHS and the fT3 levels were statistically different in the 3 groups. e LHS (in days) was, respectively, in each group, 16.77 ± 4.56, 21.98 ± 4.86, and 26.06 ± 5.47. Despite the quanti�able drop in fT3, ESS was present only at the �rst sample collection (2.61 ± 0.92 days) in Group 3, but there was no group with ESS at the second sample collection (9.89 ± 1.01 days). Our data suggest that early initiation of nutritional supplementation decreases the length of hospitalization and is associated with decreasing fT3 serum concentration depression. Conclusion. Early initiation of oral/enteral nutrition counteracts ESS and improves the LHS in burn patients