Development of microfluidic-assisted optical trapping: A novel technique for cell-membrane elasticity measurement

• Main Author: Ombid, Ric John L.
• Format: text
• Language: English
• Published: Animo Repository 2020
• Subjects: Cells—Mechanical properties; Microfluidics; Cell membranes; Atomic, Molecular and Optical Physics
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6049; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/13150/viewcontent/Ombid_RicJohn_11389230_Partial.pdf
• Institution: De La Salle University

Mechanical properties of cells, such as elasticity, adhesiveness, and viscosity, is of great interest because it is a promising label-free biomarker that indicates underlying cytoskeletal or nuclear changes. However, existing methods of measuring mechanical properties utilize pointed cantilever that damages the cells, requires dry sample preparation that does not mimic the cell environment, and involves a many-cell experiment that may lead to unreliable measurements. Here, we used microfluidicassisted optical trapping to determine the cell membrane elasticity of the human acute monocytic leukemia cell line (THP-1). The 980 nm laser at 100 mW trapped the 2 µm fused silica bead to indent the THP-1 monocytes (~10 μm) at room temperature. We treated the cells with Zeocin, a chemotherapeutic drug, as a positive control group known to upregulate cfos and cjun genes of which are markers for early apoptosis cascading cytoskeletal effects through actin filament reorganization. Results showed that untreated THP-1 cells are more elastic compared to zeocin-treated control. This suggests that THP-1 cells undergoing apoptosis are highly deformable compared to the untreated ones. Thus, the membrane elasticity measurement of cancer cells using microfluidic-assisted optical trapping provides an evaluation of treatment that activates apoptosis.