Nanogels as prospective Biomaterial: Radio-induced Synthesis, Characterization, and Biological Assays / Los nanogeles como biomateriales prospectivos: síntesis radioinducida, caracterización y ensayos biológicos

Nowadays, there is a growing interest in biodegradable polymers-based materials due to their diverse application in the biomedical field. Most studied systems involve biocompatible micro and nanodevices, such as liposomes, dendrimer, micelles or polymeric nanogels. The use of Radiation Technology, specifically gamma radiation, to produce micro and nanogels raises the possibility to obtain higher purity products, an important feature for biomedical and pharmaceutical applications. The radio-induced synthesis, characterization, cytotoxicity evaluation, and immunological response of nanogels are described in this study. Nanogel synthesis was performed in the absence of oxygen using aqueous polyvinylpyrrolidone solutions. Crosslinking reactions were carried out at 25 °C in a gamma irradiation chamber with a 60Co source. Nanogels properties were analysed by Scanning Electron Microscopy, Attenuated Total Reflection-Fourier Transform Spectroscopy, Dynamic Light Scattering, and Viscosimetry. The cytotoxicity and immunological response were evaluated by MTT test and analysis of the neutrophil respiratory burst. The results showed that nanogels formation strongly depends on the total absorbed dose. The nanogels have an elliptical shape and their chemical structure is similar to the initial polymer. The nanogels are biocompatible and promote a low-intensity neutrophil activation, similar to the well-characterized biomaterial TiO2, suggesting their potential biomedical uses(AU)

En la actualidad existe un interés creciente en los materiales biodegradables basados en polímeros, debido a sus diversas aplicaciones en la esfera de la biomedicina. En la mayoría de los sistemas estudiados participan micro- y nanodispositivos biocompatibles, tales como liposomas, dendrímeros, micelas o nanogeles poliméricos. El uso de la tecnología de radiaciones, en particular de radiaciones gamma, para producir micro- y nanogeles, eleva la posibilidad de obtener productos de mayor pureza, un rasgo importante con vistas a su aplicación biomédica y farmacéutica. El estudio describe la síntesis radioinducida, caracterización, evaluación de la citotoxicidad y respuesta inmunológica de los nanogeles. La síntesis de los nanogeles se realizó en ausencia de oxígeno, usando soluciones acuosas de polivinilpirrolidona. Las reacciones de entrecruzamiento se realizaron a 25 ºC en cámara de irradiación gamma con una fuente de 60Co. Las propiedades de los nanogeles se analizaron mediante microscopía electrónica de barrido, espectroscopia por transformada de Fourier total atenuada, dispersión dinámica de luz y viscosimetría. La citotoxicidad y la respuesta inmunológica se evaluaron mediante prueba MTT y análisis del estallido respiratorio de neutrófilos. Los resultados muestran que la formación de nanogeles depende en gran medida de la dosis total absorbida. Los nanogeles tienen forma elíptica y su estructura química es similar a la del polímero inicial. Los nanogeles son biocompatibles y promueven una activación de neutrófilos de baja intensidad similar al bien caracterizado material TiO2, lo que sugiere usos biomédicos potenciales(AU)

Identification of calmodulin-binding proteins in brain of worker honeybees.

Calmodulin is a Ca(+2)-binding protein important in a variety of cell functions. The Ca(+2)/calmodulin complex interacts with and regulates various enzymes and target proteins, known as calmodulin-binding proteins (CaMBPs). In this study, we revealed a comparative identification of the CaMBPs composition in the worker honeybee (Apis mellifera) brain, considering two different honeybee behaviors in the colony. To this end, the CaMBPs of forager and nurse workers were purified by affinity chromatography, separated in 1D gel, digested and submitted to peptide mass fingerprinting (PMF). In the PMF analysis, 15 different proteins, considered behavior-specific proteins, were identified, one of them exclusively in forager workers and 10 in nurses. All the proteins were classified in terms of their function and cell localization, revealing a greater expression of metabolism-related CaMBPs in both worker subcastes. Protein sequences were then analyzed for the presence of the calmodulin-binding sites. Therefore, the honeybee brain CaMBPs profiles presented differences between worker subcastes. This is the first identification of calmodulin-binding proteins in the brain of A. mellifera upon nursing and foraging behaviors in the colony and this diversity of target proteins for Ca(+2)/CaM may be involved in terms of the function of these proteins in the nervous system.