It’s been a while since I’ve done long-term BBB co-culture experiments on transwells but I recently completed a study. I was particularly interested to determine whether I could reproduce this spike in TEER that I measured in 1 previous experiment. I also needed repeats anyway. I followed the normal procedure – seeded P11 bEnd3 on…
Last time I cultured fibroblasts on pnc-Si transwells, the cells got super-confluent over the membrane and made the analysis difficult. Basically, I wanted to see if fibroblasts formed vacuoles/2D structures over free-standing membranes. I thought the multi-layer cells could have choked off permeability and prevented the higher layers of cells from even sensing that they…
I’ve always suspected that the pore formation process was very quick and to confirm this I looked at a wafer that was annealed for 10 s vs. 60 s. From the distributions, it would appear that the majority of pores nucleate and grow during the ramp and first few seconds of steady state. Next, I…
The goal here is to see if by using our membrane we can measure and separate different pore wall interaction effects of gas molecules passing through a pore. First, some theory. The flow through every pore of particular aspect ratio (L/d) is determined by pore’s transmission probability value (W), which is the probability of the…
Here is an attempt at the active area figure using the “newer” EO membranes (SC172). Here is the raw flow data for the three membrane sizes: If we take the slopes from this figure, we get the flow rates in uL/min. We can then plot against active area: We get a pretty nice fit here,…
Along with differently sized square membranes, I also designed a wafer with different sizes of slits. On each chip, there is a 4000, 2000, 1000 and 500um long window. The thicknesses of these windows are 200, 100, 50 and 25um. I’m interested to see if there is an aspect ratio that causes endothelial cell alignment/tubulogenesis. …
In my last post on this subject, I showed that cutting off permeability of pnc-Si chips inhibits vacuole formation in endothelial cells. To do this, I seeded cells on the membrane side, allowed them to attach, inverted them onto a media bubble contained within a cloning ring, wet the well-side with media and then placed…
One of the hidden secrets of endothelial angiogenesis assays on Matrigel is that non-endothelial cell types also form 2D capillary-like structures (tubes) on those gels. Motivated by this observation, I wanted to look at fibroblast behavior on pnc-Si transwells, specifically with respect to whether or not they formed vacuoles. Just to clarify – although Anant…
There’s been lots of discussion about “non-porous” membranes and the possibility that they are actually porous. By “non-porous”, I mean that a TEM of that membrane doesn’t have obvious pores by pore processing/our eyes. This could mean a couple things: either the pores are so small that they are hard to resolve by TEM or…
The AIM of this experiment was to see the effect of surfaces modified with PEGs (Polyethylene glycol) to protein adsorption. The PEG that I used for the current study is MS-PEG8 (Methyl-PEG8-NHS) which is Amine reactive. Method: For the current experiment I used planar silicon chips which have ~ 142 nm of thermally grown oxide….