Digitalización de la histoteca de las prácticas de Organografía Microscópica

Histoteca digital para que los alumnos puedan consultar un material gráfico actualizado y concreto, similar a lo que observan en el microscopio cuando realizan sus prácticas de Organografía de la asignatura de “Organografía microscópica” del Grado en Biología

Biocompatibility evaluation of pH and glutathione-responsive nanohydrogels after intravenous administration

Nanotoxicology has emerged as an important subdiscipline of nanotechnology due to the new healthy risks associated with the use of nanosystems for therapy and diagnostic. The biocompatibility of four stimuli-responsive nanohydrogel (NG) formulations based on different proportions of N-isopropylacrylamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and 2-acrylamidoethyl carbamate (2AAECM), and cross-linked with N,N-cystaminebisacrylamide (CBA) or N-methylenebisacrylamide (NMBA) has been evaluated after intravenous injection in Wistar rats. All nanohydrogels were pH-sensitive, and those with CBA were also glutathione-responsive. Haematological and coagulation parameters revealed most nanogel formulations did not cause modification, only the NHA 80/15/5-CBA formulation induced a transitory light increase in platelets. Prothrombin time was in the reference normal range, there were no modifications of fibrinogen concentration and an increase in antithrombin III was observed on the last day of the study. Blood biochemical parameters such as AST, ALT, ALP, BUN, and creatinine were in the standard range for rats. The activity of enzyme antioxidant defences (SOD, CAT and GSSG-R) and total glutathione were evaluated in liver, kidney and spleen samples. Nanohydrogels cross-linked with the disulphide reducible CBA-cross-linker caused a decrease in GSSG/GSH content and an increase in GSSG-R activity in the spleen. The antioxidant response is also reflected by modifications of SOD activity in liver and kidney of NHA 80/15/5-CBA and NHA 80/10/10-NMBA groups. Histology showed no tissue damage, inflammation or morphological change in liver, kidney and spleen. Overall, the results demonstrated modifications of antioxidant defences; however, no acute or very significant changes in biomarkers of liver or kidney damage were observed

In-vivo evaluation of tamoxifen-loaded microspheres based on mixtures of poly (D,L-lactide-co-glycolide)and poly (D,L-lactide) polymers

Microspheres of different proportions of poly-(D,L-lactideco-glycolide) and poly-(D,L-lactide) were formulated by spray drying as a drug-delivery system for the treatment of breast cancer with tamoxifen. These systems had been evaluated previously in vitro and showed very positive results that have led to further assessment in vivo. This work evaluates the performance of these systems in an organism by carrying out a study in female Wistar rats. Microspheres were subcutaneously injected into the back of rats for the assessment of not only the biocompatibility but also the release of the drug contained and its biodistribution. As, in vitro, these systems could release the drug under physiological conditions; different plasma concentrations of tamoxifen and one of its metabolites, 4-hydroxy-tamoxifen, were achieved depending on the polymer composition. Microspheres could reduce the accumulation of the drug in different nontarget organs and presented good biocompatibility