Anchoring PEG-oleate to cell membranes stimulates reactive oxygen species production.

Polyethylene glycol (PEG) derivatives possessing oleyl and reactive groups for conjugating functional substrates, such as proteins and quantum dots, are useful materials for cell-surface engineering and cell immobilization onto substrates. The reagent is known as a biocompatible anchor for cell membranes (BAM). Here, BAM-anchoring on cell membranes is reported to stimulate reactive oxygen species (ROS) production in those cells. Significant increases in ROS production and release to the surrounding environment were detected in mouse fibroblast cell line 10T1/2 when soaked in a solution containing BAM conjugated with 1/10mol/mol bovine serum albumin at 1.5μM-protein. ROS production stimulation was confirmed to be independent of the protein crosslinked with BAM and of cell type. Similar stimulation was detected for BAMs conjugated with ovalbumin and casein, in human hepatoma cell line HepG2, and human umbilical vein endothelial cells. Considering the effects of ROS on a variety of cellular processes, these results demonstrated the necessity for focusing attention on the effects of generated and released ROS on the behaviors of cells in the studies applying BAM to cells.