Citation
ABSTRACT [Download PDF] [View Full Text]
Objective To construct an exosome (EXO)-based nanosystem co-loaded with bovine serum albumin and isoquercitrin (BSA@ISO), and to investigate its protective mechanism against high glucose-induced damage in human retinal pigment epithelial cells (ARPE-19).
Methods EXO was extracted from ARPE-19 cells via ultracentrifugation, and the structure was observed using transmission electron microscopy (TEM). EXO markers were detected by Western blot.BSA@ISO nanoparticles were prepared using the oscillating synthesis method.A ROS-responsive EXO-based nanosystem co-loaded with BSA@ISO (BSA@ISO@EXO) was constructed using a membrane extruder.The particle size and zeta potential of BSA@ISO@EXO were measured and its morphology was observed by TEM.Chemical structure was analyzed using a spectrophotometer and infrared spectroscopy.Encapsulation efficiency and drug loading capacity were calculated using the differential method.Cells were divided into control group, model group, low-dose ISO nanosystem group (5 μmol/L ISO), medium-dose ISO nanosystem group (10 μmol/L ISO), high-dose ISO nanosystem group (20 μmol/L ISO), and pure ISO group.Cell viability at different time points was assessed using the CCK-8 assay.Apoptosis rate after 48 hours of culture was measured by flow cytometry.Levels of inflammatory factors tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the cell supernatant were determined by ELISA, while activities of antioxidant enzymes glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) and the level of oxidative stress marker malondialdehyde (MDA) in the supernatant were measured using biochemical kits.
Results The BSA@ISO@EXO nanosystem exhibited a uniform spherical shape with an average particle size of approximately 39.6 nm.UV-visible and IR spectra showed characteristic absorption peaks of BSA, ISO and EXO.The encapsulation efficiency of the nanosystem was (76.6±5.0)%, the drug loading capacity was (10.3±0.6)%, and the 24-hour drug release rate reached 75.1%.CCK-8 assay showed that cell viability in all ISO nanosystem groups after 48-hour culture was significantly higher than that in the pure ISO group (all P<0.05). The ROS level was significantly lower in the medium-dose ISO group than in the pure ISO group ( P<0.01). The levels of TNF-α, IL-1β, and MDA were significantly lower and GSH-PX and SOD activities were significantly higher in the medium-dose ISO nanosystem group than those in the model and high-dose ISO nanosystem groups (all P<0.05).
Conclusions A stable BSA@ISO@EXO nanosystem was successfully constructed.This system enhances the antioxidant and anti-inflammatory effects by improving the bioavailability of ISO, offering a new strategy for the treatment of diabetic retinopathy.
Authors Info & Affiliations