Hybrid Gold Nanoparticles: Cellular and Molecular Toxicity to Human Corneal Fibroblasts

Abstract

Purpose: We showed hybrid PEI gold nanoparticles (PEI2-GNPs) are highly potent in delivering genes into rabbit cornea in vivo and human cornea ex vivo (Nanomedicine. 2011, 7:505-13). The cytotoxicity profiling of PEI2-GNPs is necessary for the clinical usefulness of this potent nanoparticle vector for developing gene therapy for corneal diseases. The goal of the present study was to characterize the effects of PEI2-GNPs on human corneal fibroblasts proliferation, differentiation, migration, mitochondrial function, and free radical stress modulation.

Methods: Human donor corneas were used to generate corneal fibroblast (HCF) cultures. The cultures were exposed to two identified doses of PEI2-GNPs that showed significant gene transfer to the cornea in vivo (30-50%; p<0.001). The HCFs were exposed to these two doses of PEI2-GNPs for 6, 12 and 24 hours. Cellular migration was analyzed by scratch assay and HCF differentiation to myofibroblast was determined by smooth muscle actin immunofluorescence. Cellular proliferation, mitochondrial membrane potential, reactive oxygen species production, superoxide dismutase and glutathione peroxidase activity were quantified using commercial kits. H2O2 exposed HCFs were used as a positive control.

Results: The PEI2-GNPs treatment to HCFs did not alter HCF migration, differentiation to myofibroblasts, total reactive oxygen species stress, mitochondrial membrane potential or cellular viability. PEI2-GNPs showed an insignificant 6-10% decrease in HCF proliferation and caused a moderate inhibition (7-15%, p<0.05) of superoxide dismutase.

Conclusions: PEI2-GNPs appear safe for corneal gene therapy. In vivo studies are warranted to validate safety and tolerability of PEI2-GNPs.

Keywords: 484 cornea: stroma and keratocytes • 538 gene transfer/gene therapy • 607 nanotechnology