polydimethylsiloxane (pdms)-based microfluidic channel  (Dow Corning)

Journal: Biophysical Journal

Article Title: Passive and reversible area regulation of supported lipid bilayers in response to fluid flow

doi: 10.1016/j.bpj.2023.01.012

Figure Lengend Snippet: Flow alters the area of SLBs. Lipid bilayer patches were deposited on the glass coverslip base of a rectangular PDMS channel ( A and B ). Membrane patches composed of 99.2 mol % DiphyPC and labeled with 0.8 mol % Texas red DPPE initially form with smooth edges ( C and D , left columns). Upon exposure to low ( C ) or high ( D ) shear stress, lipid patches expand ( C and D , right columns). In all images, the flow direction was from right to left. To see this figure in color, go online.

Article Snippet: Rectangular polydimethylsiloxane (PDMS) microfluidic channels of dimensions 300 μ m wide and 100 μ m tall were made using a 10:1 mixture of Sylgard 184 to curing agent (Dow Corning, Midland, MI) and cured overnight at 65°C.

Techniques: Membrane, Labeling, Shear

Journal: Biophysical Journal

Article Title: Passive and reversible area regulation of supported lipid bilayers in response to fluid flow

doi: 10.1016/j.bpj.2023.01.012

Figure Lengend Snippet: ( A ) COMSOL simulation of shear stress at the lower surface of a rectangular microfluidic channel. ( B ) Values of shear stress at the coverslip surface for a range of different flow rates. Values were measured across the dotted white line in ( A ). ( C ) COMSOL simulation of shear stress at the lower surface of the neutron flow gasket. The dotted region shows the sample area where shear stress is approximately uniform, which was used to define the footprint of the neutron beam. To see this figure in color, go online.

Article Snippet: Rectangular polydimethylsiloxane (PDMS) microfluidic channels of dimensions 300 μ m wide and 100 μ m tall were made using a 10:1 mixture of Sylgard 184 to curing agent (Dow Corning, Midland, MI) and cured overnight at 65°C.

Techniques: Shear

Journal: Biophysical Journal

Article Title: Passive and reversible area regulation of supported lipid bilayers in response to fluid flow

doi: 10.1016/j.bpj.2023.01.012

Figure Lengend Snippet: DiphyPC patches on an oxidized PDMS substrate exhibit a distinct flow response depending on substrate surface roughness, as determined by AFM. Glass roughness ( A ) was small (RMS roughness = 0.2 nm), consistent with previous measurements of glass prepared by this method ( 29 ). The PDMS surface undulations ( B ) have larger wavelength and amplitude. Average surface roughness ( C ) of glass and PDMS substrate measured with AFM; error bars denote standard deviation. ( D ) After a small expansion, bright puncta appear on the membrane surface and grow in intensity over time, suggesting that membrane tubules or protrusions extend out of the supported bilayer. ( E ) Apparent membrane area compared for membrane patches on PDMS and glass over the course of two flow and rest cycles, with blue shading indicating time points when flow is turned on. Plots represent the mean response from 16 different patches for the PDMS and 13 patches on the treated glass, with shading representing the standard deviation. To see this figure in color, go online.

Article Snippet: Rectangular polydimethylsiloxane (PDMS) microfluidic channels of dimensions 300 μ m wide and 100 μ m tall were made using a 10:1 mixture of Sylgard 184 to curing agent (Dow Corning, Midland, MI) and cured overnight at 65°C.

Techniques: Standard Deviation, Membrane

Journal: bioRxiv

Article Title: Glycocalyx-Mediated Vascular Dissemination of Circulating Tumor Cells

doi: 10.1101/2020.04.28.066746

Figure Lengend Snippet: Characterization of TC arrest under flow in the MVNs. (a) Schematic diagram of the microfluidic device used to perfuse MVNs under a constant pressure difference Δ p and cells being carried by luminal flow into (A) narrow channels and (B) impacting the endothelium at bifurcations or (C) large vessels (partially realized with Biorender.com). (b) Speed of inert beads carried by luminal flow driven by different pressure differences ( n = 50 beads tracked in 3 devices, average and standard deviation shown) and arrest efficiency of TCs ( n = 4 devices, average and standard deviation shown) as a function of the pressure difference. (c) Confocal image of two arrest mechanisms showing MDA-MB-231 cells within MVNs arrested by (1) physical trapping and (2) adhesion. The scale bar is 200 µm. (d) Bead speed through the MVNs (n as above, the error bars indicate the standard deviation) and vessel diameter as a function of specific GCX component removal (the error bars indicate the standard deviation between the averages of n = 3 devices, 3 regions of interest each). (e) Arrest efficiency of TCs as a function of GCX enzymatic treatment of the MVNs alone, TCs alone, or both MVNs and TCs ( n = 4 devices). (f) Cumulative percentage of TCs either physically trapped in small vessels or adhered to large vessels in the MVNs ( n > 40 cells). Statistical significance assessed for all data portrayed by 138 student’s t-test, p < 0.05 *, p < 0.01 **, p < 0.0001 ****.

Article Snippet: Arrest and permeability experiments were conducted using custom-made three-channel polydimethylsiloxane (PDMS, 4019862, Ellsworth Adhesives) microfluidic devices with large width channels (3 mm, height of 500 μm, length of 1 cm , , ).

Techniques: Standard Deviation