Abstract
Purpose :
YSA is a peptide that binds to EphA2 receptors on vascular endothelial cells. The purpose of this study was to determine whether YSA functionalization enhances nanoparticle delivery into Human Umbilical Vein Endothelial Cells (HUVEC).
Methods :
Nile red loaded poly(lactide-co-glycolide) (PLGA) nanoparticles were prepared using double emulsion and solvent evaporation method. Nanoparticles were chemically conjugated to YSA peptide and a scrambled YSA peptide through 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl (EDAC) and N-hydroxysuccinimide (NHS) activation of carboxyl group present on acid terminated PLGA polymer. Nile red in nanoparticles was quantified using fluorescence spectroscopy following dichloromethane extraction. Nile red content was estimated by measuring fluorescence at excitation and emission wavelengths of 560 and 640 nm, respectively. NPs were dispersed in water and size and zeta potential were measured using Malvern Nano-ZS instrument. In vitro uptake of functionalized nanoparticles was determined in HUVEC cells. Briefly, 10,000 cells were seeded in 96-well plate and after 24 hour of incubation in serum containing medium, cells were washed with PBS and treated with 200 μl of 0.5 mg/ml nanoparticles in serum free medium for 3 h. At the end of the incubation period, the medium was removed, cell monolayer was washed 2 times each with physiological PBS (7.4) and acidic PBS (pH 5.2), and the cells were lysed using RIPA buffer. Nile red from particles in the lysate was extracted and quantified.
Results :
Control and functionalized Nile red loaded PLGA nanoparticles had a mean diameter of in the range of 250-300 nm and a negative zeta-potential. HUVEC cells showed ~150 % higher uptake of YSA-functionalized Nile red loaded PLGA nanoparticles, when compared to control nanoparticles. Scrambled YSA-functionalized nanoparticles showed about 90 % uptake relative to control NPs. The absolute bioavailability of control NPs was 6.7%.
Conclusions :
Functionalization of Nile red loaded PLGA NPs with YSA peptide enhances cellular delivery of nanoparticles in HUVEC cells. EphA2 receptor is a potential target for accumulating nanoparticles in vascular endothelium.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.