Vertical nanowires enhanced X-ray radiation damage of cells

•The ionizing radiation induced cell damages has been investigated by culturing cells on vertically aligned silicon nanowires.•The behavior of cells cultured on silicon nanowires have been examined in terms of cell morphology, viability, and adhesion before and after X-ray radiation.•More X-ray photoelectrons are generated from the silicon nanowire due to structure-related edge enhancement, compared to that generated from the silicon flat surface.•The increase of photoelectrons from silicon nanowire structure enhances DNA damages by ionizing more hydroxyl free radicals in cells•The enhanced X-ray radiation damage on cells is useful in assessing the effects of nanomaterials for enhanced X-ray radiation therapy