Intercellular Movement Tracking for Damage Assessment During Cell Micromanipulation

Robotic cell micromanipulation that is designed for delicate operation has brought new prospects for enhancing cell developmental potential. However, mechanical damage of cells during robotic micromanipulation cannot be ignored such that it compromises the effort of the system in improving cell viability. Therefore, cell damage assessment is particularly important, but also a great challenge due to the complexity of the composition of a cell and its functions. In this paper, a novel cell damage assessment method was proposed, relying on the sensing of mitochondrial micron-scale displacement and intracellular strain. Mitochondria in living cells were stained and used as physical markers to avoid the shortcomings of introducing physical markers into cell body. We designed a quantitative marker to characterize cell mechanical damage during the penetration process. The experimental result shows that the high-strain damage is intensified as the penetration proceeds. The maximum displacement and mean displacement were respectively 3.87 pixels (
$2.42\mu m$
) and 0.78 pixels (
$0.49\mu m$
). The maximum strain and mean strain were respectively 0.107 and 0.0143 between two adjacent frames with the micropipette speed of
$10\mu m/s$
. The maximum displacement measurement error was from 0.294 before optimization to 0.065 after optimization. The quantitative damage marker was sufficiently sensitive to sense the different levels of damage at different time sequences. At the penetration proceeds, the value of such marker at the high-strain region was several times higher than that of the low-strain region. The proposed method has implication for improving the biological efficacy of the robotic micromanipulation.