According to recent cell adhesion studies on aminosilanized pncSi, no significant difference between adherence to the silanized and non-silanized surfaces was found. This could have been due to the adsorption of protein from the cell growth media onto the surface nullifying the effect due to silanization which is supposed to make it hydrophobic. ‘If silane…
This was my first experiment in which the Sepcons were inverted for cell adhesion. After allowing the cells to attach for 4.5 hours, I inverted the Sepcons in media for staining with CMFDA. Therefore, the Sepcon is set up so that the pnc-Si side is down and the cells are “upside down”. This makes the…
I repeated the previous experiment, this time plating slightly higher density of cells: ~15100 cells/sq.cm. Samples were from the same W673, no RTP) After counting the cells stained using Calcein AM, % Adhesion w.r.t the cells plated were found to be: non-silanized samples = 55.87%; silanized samples = 41.33% In above figures, not many cells…
This is something that’s been living on my knowledge page, but I think it’s a good idea to put it up here to get some discussion on it. Probstein gives the following equation for electroosmotic velocity in his book Physicochemical Hydrodynamics: U=-εζE/μ where U is the velocity, ε the permittivity, E the electric field, ζ…
We have seen before that silanization slows down discoloration and hence prevents membrane degradation. In Sepcon, the sample should last over a week. Further, it was necessary to check whether silanized surface supports normal cell growth. Therefore, comparison of cell adhesion on aminosilanized surface is made to control surface (non silanized). I took samples from…
This is a continuation of the last post on AFM analysis of pore changes during discoloration. I took the AFM images, inverted them in ImageJ so that the pores would be white and then did PoreProcessing in MATLAB. I simply selected a threshold but did no binary operations. The calibration for these AFM images was…
To complement the recent study which investigated pore changes during discoloration with TEM, I did AFM on the same samples. These were w673 samples which were incubated in DMEM (-FBS) in the 37C oven. We didn’t use FBS because I thought the serum proteins would have adsorbed to the samples and then made AFM analysis…
As seen before, in 2D format ‘RTP+silanization’ helps. Similarly in 3D format, with membrane side down, the same treatment helps prevent discoloration till 5 days. (samples from W413) Above figure shows how combined effect of RTP and silanization is better than just RTP/Silanization or none. (the weird discoloration pattern could be a result of few…
Chris gave me a few wafers to look at with AFM – an oxide sputtered in the recently cleaned chamber and VA Semiconductor wafers cleaned with “Normal Power” or “Full Power” Megasonics. I employed a couple of new “tricks” to help with the imaging this time. All of these scans were taken almost entirely in…
In continuation of the previous post, I ran the pore processing software for two samples (t=0 and t=150 min). The following histograms show the pore parameters and the difference in the pore size and numbers between the two samples. I am not sure if the difference between the pore sizes could be due to sample-sample…