title: Microfluidic approach for direct and uniform laser irradiation to study biochemical state changes on Jurkat-T cells.
abstract: We investigated the potential for using polydimethylsiloxane microfluidic devices in a biological assay to explore the cellular stress response (CSR) associated with hyperthermia induced by exposure to laser radiation. In vitro studies of laser-tissue interaction traditionally involved exposing a monolayer of cells. Given the heating-cooling dynamics of the cells and nutrient medium, this technique produces a characteristic "bulls-eye" temperature history that plagues downstream molecular analyses due to the nonuniform thermal experience of exposed cells. To circumvent this issue, we devised an approach to deliver single cells to the laser beam using a microfluidic channel, allowing homogeneous irradiation and collection of sufficient like-treated cells to measure changes in CSR after laser heating. To test this approach, we irradiated Jurkat-T cells with a 2-μm-wavelength laser in one branch of a 100-μm-wide bifurcated channel while unexposed control cells were simultaneously passing through the other, identical channel. Cell viability was measured using vital dyes, and expression of HSPA1A was measured using reverse transcription polymerase chain reaction. The laser damage threshold was 25 ± 2 J/cm2, and we found a twofold increase in expression at that exposure. This approach may be employed to examine transcriptome-wide/proteome changes and further comparative work across stressors and cell types.
authors.affiliation: University of North Texas, Department of Physics, 1155 Union Circle, #311427, Denton, Texas 76203.
authors.forename: Sween J
authors.initials: SJ
authors.lastname: Butler
authors.forename: Dong Weon
authors.initials: DW
authors.lastname: Lee
authors.forename: Curtis W
authors.initials: CW
authors.lastname: Burney
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Wigle
authors.forename: Tae Youl
authors.initials: TY
authors.lastname: Choi
mesh_terms: D002470:Cell Survival / Q000502:physiology / Q000528:radiation effects; D003584:Cytological Techniques / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D019169:Jurkat Cells; D007834:Lasers; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D013312:Stress, Physiological