Delivery of natural polyphenols by polymeric nanoparticles improves the resistance of endothelial progenitor cells to oxidative stress

Abstract

Purpose: Bone marrow-derived endothelial progenitor cells (EPCs) circulate into peripheral blood and significantly contribute to neo-vascularisation and re-endothelialisation as part of the process of vascular repair. Several studies have reported decreased EPC number in the presence of oxidative stress. Aim of this study was to evaluate the validity of mucoadhesive polymeric nanoparticles as a delivery system of natural products able to protect EPCs from oxidative stress.

Methods: The total polyphenol content and antioxidant capacity of red grape seed extract (GSE) either pre-veraison (p-GSE) or ripe (r-GSE) were measured. Cell viability was evaluated by WST-1 assay. Nanoparticles were prepared by ionotropic crosslinking of two structurally different thiolated quaternary ammonium-chitosan conjugates. A hyaluronic acid solution, containing p-GSE or r-GSE, was added to a stirred solution of each of the two chitosan derivatives to obtain p- or r-GSE loaded nanoparticles (NP) of two types.

Results: Both GSE types demonstrated strong antioxidant capacity. p-GSE showed a higher content in total polyphenols compared to r-GSE. NP size was in the 310-340 nm range, with 24 h stability, and nearly 100% encapsulation efficiency for both GSE types. NP were internalized by cells to an extent related directly with their surface charge intensity. GSE-NP uptake significantly improved cell viability and resistance to oxidation.

Conclusions: Nanotechnology has a great potential in nutraceutical delivery. The present results suggest that NP is a highly promising polyphenol carrier system particularly useful to protect EPCs from oxidative stress, thus improving their survival.

Keywords: CAD; Ch; Chitosan–hyaluronan nanoparticle; EPCs; Endothelial progenitor cell; FBS; FITC; GS; GSE; Grape seed extract; N+-rCh(50°)-SH/rHA nanoparticles; N+-rCh(60°)-SH/rHA nanoparticles; N+Ch; N+Ch-SH; NO; NP; NP1; NP2; Oxidative stress; PBMCs; ROS; Resv; VEGF; chitosan; coronary artery disease; endothelial grow factor; endothelial progenitor cells; fetal bovine serum; fluorescein isothiocyanate; grape seed extract; grape seeds; nanoparticles; nitric oxide; p-GSE; peripheral blood mononuclear cells; pre-veraison grape seeds extract; quaternary ammonium-chitosan conjugate; r-GSE; rCh; rHA; reactive oxygen species; reduced-molecular weight chitosan; reduced-molecular weight hyaluronic acid; ripe grape seeds extract; thiolated quaternary ammonium-chitosan conjugate; trans-resveratrol.