Modeling VEGF Concentration Gradients

Concentration gradients of VEGF in transwell assays and in the gLL were modeled in COMSOL Multiphysics 5.3a (COMSOL Multiphysics 5.3a, COMSOL Inc., Burlington, USA) using physical properties of VEGF and the true geometry of the assays, as per manufacturer references and our own measurements (Cat No. 3464, Corning Incorporated, NY). Transport of EGF and VEGF within the gLL and transwell assay was computationally modeled to predict reagent concentration over time across the microchannel and permeable membrane, respectively. The diffusivity of EGF was estimated to be 2.0 × 10⁻⁶ cm²/s for EGF [45 (link)], and 9.0 × 10⁻⁷ cm²/s for VEGF using the Stokes–Einstein equation [46 (link),47 (link),48 (link)].