Reproductive cycle of the sea urchin Paracentrotus lividus in the Cantabrian Sea (northern Spain): environmental effects

The main objective of this study was to describe the reproductive cycle of the sea urchin Paracentrotus lividus on the Cantabrian coast (north of Spain), and assess its relationship with environmental factors. To achieve this, samples were taken monthly from three localities during 17 months in two different habitats. At least 15 individuals from each location and habitat were collected during each sampling occasion and used for assessments of gonad index and histological sections. The water temperature and the chlorophyll concentration were also measured. The breeding season of P. lividus in Cantabria started in March and continued until September with one or two main spawning periods per year (depending on year and population), the first one in the beginning of spring and the second one in the summer. The most important differences in the gonad cycle were observed among localities, and the smallest among habitats. Temperature, photoperiod and nutritive stage are important factors controlling the gonad cycle. The beginning of spawning in the Cantabrian populations coincides with the spring phytoplankton bloom and the rise in temperature, which may act as environmental triggers

Hipoxia-isquemia neonatal: bases celulares y moleculares del daño cerebral y modulación terapéutica de la neurogénesis

INRODUCCIÓN. La asfixia perinatal continúa siendo una de las mayores causas de morbimortalidad neurológica. La encefalopatía neonatal derivada constituye una causa importante de daño cerebral, que afecta de manera moderada-grave a 1-3 de cada 1.000 recién nacidos y comporta un alto riesgo de déficits neurológicos permanentes. La única aproximación terapéutica actual consiste en la hipotermia moderada, cuya eficacia, aunque constatada, no siempre consigue una recuperación funcional total. DESARROLLO. Se desconoce con certeza si la hipotermia tiene la capacidad de promover la proliferación celular en los nichos neurogénicos cerebrales, donde permanecen células madre neuronales con capacidad de proliferación y diferenciación. El empleo de agentes terapéuticos, como la eritropoyetina o los cannabinoides, y de células madre mesenquimales ha mostrado resultados prometedores en diversos modelos experimentales de asfixia perinatal y es capaz de modular los procesos de neurogénesis, de plasticidad neuronal y de neurorreparación tras un daño cerebral hipóxico-isquémico. CONCLUSIONES. Aún se desconocen los efectos de estas terapias en modelos clínicos y si las células recién formadas serán capaces de integrarse de forma efectiva en las redes neuronales existentes o si podrán desarrollar sus funciones adecuadamente en un microambiente de lesión cerebral, por lo que se hace necesario el desarrollo de nuevos trabajos enfocados a evaluar el potencial real de estos agentes en la modulación terapéutica de la neurogénesis tras una hipoxia-isquemia neonatal

MiR-219a-5p enriched extracellular vesicles induce OPC differentiation and EAE improvement more efficiently than liposomes and polymeric nanoparticles

Remyelination is a key aspect in multiple sclerosis pathology and a special effort is being made to promote it. However, there is still no available treatment to regenerate myelin and several strategies are being scrutinized. Myelination is naturally performed by oligodendrocytes and microRNAs have been postulated as a promising tool to induce oligodendrocyte precursor cell differentiation and therefore remyelination. Herein, DSPC liposomes and PLGA nanoparticles were studied for miR-219a-5p encapsulation, release and remyelination promotion. In parallel, they were compared with biologically engineered extracellular vesicles overexpressing miR-219a-5p. Interestingly, extracellular vesicles showed the highest oligodendrocyte precursor cell differentiation levels and were more effective than liposomes and polymeric nanoparticles crossing the blood–brain barrier. Finally, extracellular vesicles were able to improve EAE animal model clinical evolution. Our results indicate that the use of extracellular vesicles as miR-219a-5p delivery system can be a feasible and promising strategy to induce remyelination in multiple sclerosis patients

Emerging era of “somes”: polymersomes as versatile drug delivery carrier for cancer diagnostics and therapy

Over the past two decades, polymersomes have been widely investigated for the delivery of diagnostic and therapeutic agents in cancer therapy. Polymersomes are stable polymeric vesicles, which are prepared using amphiphilic block polymers of different molecular weights. The use of high molecular weight amphiphilic copolymers allows for possible manipulation of membrane characteristics, which in turn enhances the efficiency of drug delivery. Polymersomes are more stable in comparison with liposomes and show less toxicity in vivo. Furthermore, their ability to encapsulate both hydrophilic and hydrophobic drugs, significant biocompatibility, robustness, high colloidal stability, and simple methods for ligands conjugation make polymersomes a promising candidate for therapeutic drug delivery in cancer therapy. This review is focused on current development in the application of polymersomes for cancer therapy and diagnosis. Graphical abstract