Traction force screening enabled by compliant PDMS elastomers

Abstract

Abstract:Acto-myosin contractility is an essential element of many aspects of cellular biology, and manifests as traction forces that cells exert on their surroundings. The central role of these forces makes them a novel principal therapeutic target in diverse diseases. This requires accurate and higher capacity measurements of traction forces; however, existing methods are largely low throughput, limiting their utility in broader applications. To address this need, we employ Fourier-transform traction force microscopy in a parallelized 96-well format, which we refer to as contractile force screening (CFS). Critically, rather than the frequently employed hydrogel polyacrylamide (PAA), we fabricate these plates using polydimethylsiloxane (PDMS) rubber. Key to this approach is that the PDMS used is very compliant, with a lower-bound Young's modulus of approximately 0.7 kPa. We subdivide these monolithic substrates spatially into biochemically independent wells, creating a uniform multiwell platform for traction force screening. We demonstrate the utility and versatility of this platform by quantifying the compound and dose-dependent contractility responses of human airway smooth muscle cells and retinal pigment epithelial cells.

Intercellular communication controls agonist-induced calcium oscillations independently of gap junctions in smooth muscle cells

“…S1A). The substrate that we use is NuSil (11), an optically clear, nonporous polydimethylsiloxane (PDMS) substrate whose Young's modulus, E, can be varied in the range of 0.3 to 70 kPa (11). On the basis of the measurements of ECM stiffness in healthy human airways, we set the ECM stiffness of healthy human airways to E = 0.3 kPa (12).…”

Where No Hand Has Gone Before: Probing Mechanobiology at the Cellular Level

“…The first technique developed to measure the forces exerted by cells on their substrate is traction force microscopy (TFM). 35,36 TFM uses soft gel matrices, such as polyacrylamide (PAA) 35 or polydimethylsiloxane (PDMS), 37 as cell culture substrates with fiducial markers, such as fluorescent beads, dispersed in the gel. As cells spread and migrate on these substrates, they exert traction forces that deform the gels.…”

Cooperativity between β‐agonists and c‐Abl inhibitors in regulating airway smooth muscle relaxation

“…Contractile traction force changes were evaluated by Contractile Force Screening (CFS) as per methods described previously 22 . Briefly, 96‐well plates with miniaturized Polydimethylsiloxane (PDMS) substrates bearing surface‐bound fluorescent microspheres were plated with primary human ASM cells.…”

“…Contractile traction force changes were evaluated by Contractile Force Screening (CFS) as per methods described previously. 22 Briefly, 96-well plates with miniaturized Polydimethylsiloxane (PDMS) substrates bearing surfacebound fluorescent microspheres were plated with primary human ASM cells. The ASM cells were treated with 10 µM histamine for 30 minutes followed by treatment with ISO (1 μM), the c-Abl inhibitor imatinib (10 μM), or a combination as indicated for an additional 30 minutes.…”