HeLa Cell Culture Temperature Effects on Nanoinjection Efficiency
Bradley Hanks
John Sessions
Brian D. Jensen
Dept. of Mechanical Engineering
Brigham Young University
Provo, UT 84602
ABSTRACT
Nanoinjection is a developing process in gene therapy used to introduce foreign molecules into the cell.
Nanoinjection of HeLa cells using Propidium Iodide (PI) was used to test the effects of varying the temperature of
the cell culture during injection. Nanoinjection utilizes a silicon wafer with over four million lances to pierce the cell
membrane, thus creating pores which allow particles to be introduced into the cell. Temperature changes in a
cell’s environment significantly alter its membrane and functionality. Previous studies have shown that the cell
membranes stiffen and the abilities of a cell to function slow at colder temperatures. HeLa cell cultures were
injected at room temperature (~25 ˚C) and while on ice (~0 ˚C) using both 5V and 7V pulses to test for variations
in uptake efficiencies. PI added at various time intervals (0, 3, 6, 9 min following injection) was used to track when
PI was taken up into the cell. Results show that PI was introduced into cell cultures on ice at significantly higher
rates when compared to room temperature samples. Samples pulsed with 5V and 7V on ice consistently showed
an uptake 2.4 times greater than room temperature injections. Therefore, reducing the temperature of a cell
culture during injection suggests that the pores are more effective for introducing molecules into a cell.