SU‐G‐TeP3‐07: On the Development of Mechano‐Biological Assessment of Leukemia Cells Using Optical Tweezers

Abstract

Purpose:Patients with BCR‐ABL (Ph +ve) acute lymphoblastic leukemia are at very high risk of relapse and mortality. In line with the NIH mission to understand the physical and biological processes, we seek to report mechano‐biological method to assessment and distinguish treated/untreated leukemia cells.Methods:BCR‐ABL leukemia cell populations and silica microspheres were trapped in a 100x magnification optical trapping system (λ=660 nm, 70 mW). Light refracted through the trapped sample was collected in the back focal plane by a quadrant detector to measure the positions of individual cells. The sample was driven at a known frequency and amplitude with a flexure translation stage, and the target's response was recorded. The measured response was calibrated using the known driving parameters, and information about cell movements due to mechano‐biological effects was extracted. Two leukemia cell populations were tested: a control group and a group treated with 2 Gy.Results:The mechano‐biological movements of 10 microspheres, control cells, and treated cells were tracked over a ∼30 minute window at 1 minute intervals. The microsphere population did not see significant change in mechano‐biological movements over the testing interval and remained constant. The control cell population saw a two‐fold rise in activity that peaked around 1200 seconds, then dropped off sharply. The treated cell population saw a two‐fold rise in activity that peaked at 400 seconds, and dropped off slowly.Conclusion:The investigated technique allows for direct measurement the movements of a trapped object due to mechano‐biological effects such as thermal and extracellular motion. When testing microspheres, the mechano‐biological activity remained constant over time due to the lack of biological factors. In both the control and treated cell populations, the mechano‐biological activity was increased, possibly due to mitochondrial activation. This extra activity decreased over time, possibly due to cellular damage from trapping radiation.