Saez, V; Ramón, J; Aldana, R; Pérez, D; Hardy, E
Interferon-α2b (IFN-α2b) produced in Cuba by the Center for Genetic Engineering and Biotechnology was encapsulated into poly (D,L-lactide-co-glycolide) (PLGA) microspheres using the double emulsion-solvent evaporation method. Resulting microspheres showed smooth surfaces containing randomly distributed pores, a mean diameter of 28.1 ± 0.4 µm (using 14,000 rpm for the second emulsification step), PLGA recovery of 86 ± 1%, loading between 0.41 and 1.23% for interferon at 5-20 mg/mL in the inner aqueous phase, with the corresponding encapsulation efficiency of 79 and 56%. The encapsulated interferon was extracted by both passive diffusion and solvent extraction techniques and further characterized. No changes were detected in the physico-chemical and biological characteristics of the IFN-α2b recovered by diffusion-controlled release for 24 h at 37 °C. In contrast, the solvent-extracted fraction showed 43 ± 4% of immunorecognized IFN-α2b and 61% of its initial antiviral activity (1.7 x 108 IU/mg). These instabilities were due to the encapsulation method, and not to spontaneous IFN-α2b modifications. Consequently, IFN-α2b showed potential for encapsulation in PLGA microspheres for controlled release. (English) [ABSTRACT FROM AUTHOR] En este trabajo se encapsulo interferon-α2b (IFN-α2b), producido en Cuba por el Centro de Ingenieria Genetica y Biotecnologia, en microesferas de poli (D,L-lactida-co-glicolida) (PLGA) por medio del metodo de doble emulsion-evaporacion del disolvente. Las microesferas resultantes mostraron superficies regulares con poros distribuidos aleatoriamente, un diametro promedio de 28.1 ± 0.4 µm (al emplear 14 000 rpm para obtener la segunda emulsion), un recobrado de PLGA de 86 ± 1%, cargas entre 0.41 y 1.23% al utilizar interferon a 5-20 mg/mL en la fase acuosa interna, con eficiencias de encapsulacion correspondientes entre 79 y 56%. El interferon encapsulado fue extraido de las microesferas para su caracterizacion, mediante difusion pasiva o por la accion de disolventes. No se detectaron cambios en las caracteristicas fisico-quimicas y biologicas del IFN-α2b liberado por difusion durante 24 h a 37 oC. Sin embargo, la fraccion de IFN-α2b extraida por medio de disolventes mostro un inmuno-reconocimiento de 43 ± 4% y 61% de su actividad antiviral inicial (1.7 x 108 IU/mg). Estos cambios se debieron al metodo de encapsulacion y no a modificaciones espontaneas del IFN-α2b. En consecuencia, el IFN-α2b puede, potencialmente, ser encapsulado en microesferas de PLGA para su aplicacion en liberacion controlada. (Spanish) [ABSTRACT FROM AUTHOR] Copyright of Biotecnologia Aplicada is the property of Elfos Scientiae and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)