Introduction We are differentiating and validating EECM-BMEC (Extended Endothelial Cell Culture Method-Brain Microvascular Endothelial Cell)-like cells in µSiM devices. See this post and this post for method details and validation in traditional cell culturing platforms. Methods Attempt 1 – Overstimulated cells IMR90-4 iPSC EECM-BMEC P3 frozen vial was thawed. At P4 cells were seeded and cultured 2…
Introduction Pages regarding our in situ permeability assay development can be found in these links: Theoretical Underpinnings of Small Molecule Permeability Measurements in the µSiM (Part 1: Approach) Theoretical Underpinnings of Small Molecule Permeability Measurements in the µSiM (Part 2: Experimental Validation) Theoretical Underpinnings of Small Molecule Permeability Measurements in the µSiM (Part 3: Application to Cell…
Competitive ELISA assay to measure the HA shedding from HUVEC monolayer Introduction The endothelial glycocalyx is a dense layer of proteoglycans, glycoproteins, and glycosaminoglycans (GAGs) that helps maintain the integrity of the endothelial cell (EC) barrier.1 The main GAGs are heparan sulfate (HS), chondroitin sulfate, and hyaluronic acid (HA), among which HS and HA are…
Background We at Michigan have been aiming to perform sequential small volume sampling coupled with our ultrasensitive digital immunoassay to provide longitudinal data from the uSIM. We have encountered repeatability problems as well as low molecule abundancy with shortly incubated samples collected from the bottom microfluidic channel. Therefore, COMSOL simulation work has been done to…
Motivation We have discussed the optimization of our in situ permeability assay at length. This assay relies on confocal microscopy, which may not be accessible to all users of the µSiM. Therefore, we developed an alternative permeability assay in the µSiM that is an endpoint, sampling assay. The protocol for this assay can be found…
Introduction & Motivation A subset of cancer cells has mutations that generate proteins recognized by the immune system as foreign, triggering the immune-mediated clearance of those cells. To avoid this fate, cancer cells can evolve mechanisms to suppress this antitumor response via the regulation of immune checkpoint pathways. Immune checkpoints describe mechanisms that are in…
Although most previous studies suggest a weakened cell-substrate interaction over porous membranes, there are variations in the observed cell responses, likely due to the use of different cell types, substrate materials, and experimental methods. We are seeking to develop a computational model using the Active Brownian Particle (ABP) approach to study the role of pore…
The development of the μSiM-DX has been swift and focused, as discussed in these previous blog posts: https://trace-bmps.org/beadazzled-laying-the-foundation-of-the-%ce%bcsim-dx-fouling-based-sensor/ and https://trace-bmps.org/vindictive-virus-capture-testing-the-%ce%bcsim-dx-with-vaccinia-virus-towards-a-modular-virus-diagnostic/. To provide a greater understanding of the inner workings of the device, I have done a few calculations regarding some of its working properties related to microfluidics. The three I present here are about the relationship…
One of the many contributions Alec S. made to our group is to help us appreciate the importance of the apicobasal (A/B) polarity of endothelial cells. The effects of A/B polarity were demonstrated in his paper: Integrative Biology (2020), 12(11),275–289 where he showed that stimulation of ECs with TNFα from the abluminal chamber caused an…
After completing proof of concept testing with polystyrene beads and with the goal of creating a SARS-CoV-2 sensor (Discussed in this post: https://trace-bmps.org/beadazzled-laying-the-foundation-of-the-%ce%bcsim-dx-fouling-based-sensor/), we sought to test the performance of the system with a target more similar to the SARS-CoV-2 virus. We found this target in vaccinia virus. As we did with the polystyrene beads,…