Preparation of Double-Layer Nanoparticles for Inhibitory Efficiency in Vascular Restenosis via Balloon Infusion

Abstract

ABSTRACTThe effect of double-layer nanoparticles (DNPs) on vascular restenosis was investigated in this study, which were prepared by combining vascular endothelial growth factor (VEGF) and paclitaxel (PTX). Different blank NPs (Blank), VEGF NPs, PTX-NPs single-layer NPs (PTX-NPs), and DNPs were prepared with VEGF, PTX, polylactic-polyglycolic acid (PLGA), and polyvinyl alcohol (PVA), so as to analyze the cytotoxicity of NPs. Besides, different NPs were compared in terms of the characterization, encapsulation efficiency (EE), in vitro release (IVR), and cell proliferation inhibition ability. 30 adult New Zealand white rabbits were selected to construct a balloon injury model (BIM). Then, they were divided into 5 groups according to different treatment NPs, including a model group (BIM), a Blank group (BIM + Blank NPs); a PTX-NP group (BIM + PTX-NPs), a VEGF-NPs group (BIM + VEGF-NPs), and DNPs group (BIM + DNPs), with 6 rabbits in each group. There was a comparison on the histology, arterial stenosis, hyperplasia index (HI), and intimal thickness (IT) of arterial vessels from different groups, and immunohistochemistry was employed to analyze the changes of VEGF and C-reactive protein (CRP) protein expression levels in arterial tissues of different groups. The results showed that the cell survival rate (SR) was 88.69 ±3.17% and 90.64 ± 1.86% in turn when PLGA and PVA were both 100 ¿tg/mL. The polydispersity index (PDI), minimal Zeta potential (ZP), and average particle size (APS) of DNPs were 0.16 ±0.02, -8.45 ±0.07, and 242.26 ±2.58 nm, respectively. The drug loading (DL) of PTX and plasmid VEGF 165 in DNPs were 29.33% and 4.93%, respectively. The release of PTX from DNPs on the 30th day was close to 50%, and the cumulative release of deoxyribonucleic acid (DNA) was close to 75%. There was no obvious difference in the cell SR within 7 days after DNPs were added into Chinese Hamster ovary (CHO) cells and vascular smooth muscle cells (VSMC) compared with the control group (P > 0.05). The arterial stenosis, HI, and IT of the DNPs group were greatly lower than those of the model group (P < 0.05). The expression of VEGF protein in arterial tissues of DNPs group was higher in contrast to the model group (P < 0.01), while the expression of CRP protein was lower than that of the model group (P < 0.05). It showed that the DNPs combined with VEGF and paclitaxel administered by balloon infusion could obviously inhibit the vascular restenosis by increasing the expression of VEGF and reducing the expression of CRP, which provided a reference for the clinical prevention and treatment of postoperative vascular restenosis.