Introduction of membrane-impermeant substances into living cells is the key method such as microinjection and electroporation to understand contemporary cellular processes by investigating cellular responses and phenotypes. Ion beams, for example, which have been widely used in the field of modification and processing of materials to enable the proper functioning of semiconductor transistors and having the desired material surface properties are being increasingly used in biological studies, including cancer therapy, as a beneficial alternative to conventional radiotherapy. Heavy-ion microbeams have been commonly used to induce mutations and chromosomal aberrations based on the assumption that bombardment with high-energy ions disrupts the deoxyribonucleic acid (DNA) structure. Thus far, no studies have reported the implantation of ion species into living cells to modify cellular functions.

Here, we performed gold atom doping into live cells by using the focused ion beam implantation method. We evaluated the viability of the gold-implanted cells by measuring the concentration of adenosine triphosphate (ATP), which is an intracellular energy source produced in the mitochondrial membrane. The viability of the implanted cells was found to be 20% higher than that of the unimplanted control cells. The implanted atoms might promote the energy generating processes within the mitochondrion.

Our results suggest that the viability of live cells can be modulated by accurately controlling the dopant atom numbers. Our ion implantation technique may be considered as a more accurate tool to quantitatively elucidate the dose-dependent effects of dopants than the conventional methods.

Takahiro Shinada, Waseda Institute for Advanced Study, Waseda University, Japan
Takayuki Akimoto, , 
Hisa Goke, , 
Masahiro Hori*, Waseda Institute for Advanced Study, Waseda University, Japan

*presenting author