In Vitro AuNPs' Cytotoxicity and Their Effect on Wound Healing.

Recently, due to their unique properties, gold nanoparticles (AuNPs) have been used in many biological applications. However, little is known about their toxicity when they come into contact with a biological system. Based on the proposal that AuNPs can have a positive effect on wound healing, the present study investigated the influence of negatively-charged-surface AuNPs (average diameter 25-50 nm) on the viability of normal human dermal fibroblasts (NHDF) and normal human epidermal keratinocytes (NHEK). Moreover, we evaluated the effect of AuNPs on the secretion of proteins involved in wound healing, such as interleukin-8 and - 12 (IL-8, IL-12), tumour necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), basic fibroblast grow factor (bFGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF). The results showed that AuNPs were not toxic to NHDF and NHEK. They showed a decrease in AuNPs' production of pro-inflammatory cytokines IL-6, IL-12 and TNF-α, as well as proteins involved in angiogenesis such as VEGF and bFGF. Thus, we suggest that AuNPs could have anti-inflammatory and anti-angiogenic activity.