Inactivation of HeLa cells on nanoporous gold

Nanoporous metals strongly affect organic matter; however, there is a poor understanding of their effects on cells. The present work shows that HeLa cells on nanoporous gold (NPG) were less active than those on flat gold (FG) with no nanoporous structure. Initially, HeLa cells adhered to the NPG over a period of more than 10 h, then the adhered cells subsequently exhibited apoptosis that was not related to anoikis. ELISA analyses showed that the conformational change of fibronectin was more greatly induced by NPG than FG. First-principles calculations and molecular dynamics simulations were performed to investigate the conformational change in the RGD sequence and the integrin signaling. The simulations suggested that the extended form of integrin, with an open headpiece, was not generated owing to the conformational change of RGD, and the outside-in signals could not be intracellularly transmitted via the integrin binding to the fibronectin on NPG, resulting in cell death