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The influence of gamma-sterilization on the physicochemical properties of a controlled release formulation for the insulin-like growth factor-I (IGF-I) was investigated in this study. Recombinant human insulin-like growth factor-I (rhIGF-I) was efficiently entrapped in poly (D,L-lactide-co-glycolide) (PLGA) microspheres by water-in-oil-in-water (W/O/W) solvent evaporation technique. Microspheres were irradiated at a dose of 25kGy and evaluated by means of scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The stability of the released protein was investigated by circular dichroism (CD) and sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE). No difference was noticed in microsphere size and morphology before and after irradiation. Drug loading remains essentially the same after the sterilization process. However, rhIGF-I aggregation was detected by electrophoresis. In addition, subtle changes in DSC pattern were noticed for irradiated microspheres. In vitro drug release from irradiated microspheres was also affected, showing an increased burst effect. From this results it can be concluded that gamma-sterilization process causes changes in the properties of rhIGF-I loaded microspheres.

Insulin-like growth factor-I (IGF-I) is a naturally occurring single chain polypeptide of 7649 Da that is produced primarily in the liver. The metabolic activities of IGF-I are similar to those of insulin and its effects on growth, development, regeneration and metabolism have been widely studied. Indeed, IGF-I is currently being used clinically for the treatment of growth related disorders and its therapeutic value is also being evaluated in diabetes, IGF-I-induced neuroprotection, and in promoting bone healing. However, like many other peptides, IGF-I has a short biological half-life and is rapidly removed from circulation following systemic administration. In the vascular system, this is normally compensated for by the association of IGF-I with IGF-binding proteins (IGFBPs), that also appear to regulate the activities of IGF-I. Here, we describe the biopharmaceutical properties of different parenteral formulations of IGF-I. The pharmaceutical characteristics of conventional formulations such as aqueous IGF-I solutions are compare with new controlled release formulations such as multivesicular liposomes, osmotic minipumps, and poly (DL-lactic-co-glycolic) acid (PLGA) microspheres.

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Este artículo presenta un estudio sobre las terminaciones -i/-is y -e/-es en la comunidad de habla LGTBI. La motivación de esta investigación viene de la representación del género no binario en la lengua española, marcado recientemente por las terminaciones en -e, que además es utilizado para crear un plural inclusivo que evite el masculino genérico. En la misma línea, se han detectado usos, dentro de la comunidad de habla LGTBI, de otro grupo de terminaciones (-i/-is) que parecen anular la distinción de género. Los datos han sido extraídos de una encuesta sociolingüística elaborada por el autor de este trabajo. En la parte sociolingüística se pretende perfilar el tipo de usuario de estas terminaciones, hacia quiénes van dirigidas y con qué intención. En la parte pragmática se analizarán las funciones que se activan con el uso de estas terminaciones, centrando el análisis en la performatividad, la atenuación y la afiliación.