Tailoring PEGylated nanoparticle surface modulates inflammatory response in vascular endothelial cells

Polymer nanoparticles (NPs) are extensively studied as drug delivery systems for various therapeutic indications, including drug and imaging agent delivery to the brain. Despite intensive research, their toxicological profile has yet to be fully characterized. In particular, the more subtle effects of nanomaterials on inflammatory processes have scarcely been investigated. Surface properties of NPs are amongst parameters governing interactions between living cells and NPs. They could considerably influence the toxicity and inflammatory response of the cells exposed to NPs. Polymeric NPs investigated here present a core-shell structure. The core is constituted of hydrophobic poly(lactic acid) (PLA) block and the surface is composed of a shell of hydrophilic block of polyethylene glycol (PEG). The effect of PEG chain length coating on the expression of genes involved in the inflammation response was investigated in two vascular endothelial cell lines (bEnd.3 and HUVEC) by qPCR. Moreover, ROS generation following NP uptake was evaluated. PEGylated NPs induce a mild and transient activation of inflammatory cytokine and chemokine genes. However, differences in PEG chain length did not show any significant effect on cytokine and chemokine gene expression and PEGylated NPs did not trigger ROS generation. The present results could contribute significantly to a deeper understanding of nanomaterial interactions and toxicity with vascular endothelial cells, guiding scientists in material coating choices.