Idebenone addition in protein‐loaded PLGA/VitE microspheres as neuroprotective IODDS

Abstract

Purpose: Anti‐inflammatory and antioxidant evaluation of idebenone (IDB) in ARPE‐19 cell line and subsequent encapsulation in PLGA (polylactic‐co‐glycolic‐acid)/vitamin E microspheres (MS), together with neurotrophic factors, to confer additional neuroprotective activity and technological advantages.Methods: ARPE‐19, a human RPE cell line, were incubated for 24 with IDB (0.5‐150 μM) to determine cell viability by MTT assay. For anti‐inflammatory evaluation, cells were pre‐treated with IDB (10 μM) for 3 h and then, stimulated with LPS (10 μg/mL;24 h). Interleukin‐6 (IL‐6) and chemokine CCL2 levels were quantified by ELISA. To determine the antioxidant activity of IDB, the induction of intracellular reactive oxygen species (ROS) was investigated. Cells were 3 h pre‐treated with IDB (10 μM), posterior exposed to hydrogen peroxide (H2O2) (100 μM;6 h), and measured by a Cellular ROS Assay kit. The elaboration of the PLGA/vit E MS loaded with IDB and protein was carried out by the method of extraction‐evaporation of the solvent from an S/O/W emulsion. Microspheres were characterized by SEM, Confocal microscopy and LDS. The protein encapsulation efficiency and the % released in the first 24 h of in vitro release study was measured by fluorimetry.Results: IDB (10 μM) significantly suppressed LPS‐induced secretion of IL‐6 and CCL2 in ARPE‐19 cells. Moreover, pretreatment with the additive significantly attenuated the increased ROS levels in H2O2‐induced cells. Monodisperse spherical MSs were obtained with mean particle size suitable for intravitreal injection (29.41 ± 0.34 μm) and small superficial porous due to the presence of VitE. MSs showed a protein‐loading of 64.48 ± 1.99%. According to confocal images, protein was mainly distributed on the MS core. The initial protein release was 57.21 ± 10.89%.Conclusions: The inclusion of IDB in the PLGA/VitE MSs loaded with active proteins could increase the neuroprotective activity of the IODDS as well as improve its technological characteristics.