I was given three groups of chips to SEM. The first group had undergone the Diazerine and PEG1000 treatment followed by incubation with either PBS, IgG, or BSA. The second ‘group’ was a chip that had been treated with diazerine…
Author: Dean Johnson
Dr. Johnson is a Research Assistant Professor in Nephrology who was awarded an R01 in 2020. He earned his Ph.D. in Microsystems Engineering from RIT and is currently working on hemodialysis devices based on the ultrathin nanoporous membranes developed earlier by this group.
Burst Pressure NPN, thermal oxide, and PBS exposure
Hemodialysis chips are not surviving the priming process and the 4 hour dialysis treatment. We want to verify that the membranes are being weakened and also to determine if coating with oxide will ameliorate the problem. Using single slot chips…
Posted in NRG
Surface Modification for Hemodialysis
We are continuing to work with the Shestopalov lab on surface modifiation of hemodialysis filters to prevent adhesion and activation. Jim recently presented our status and strategy (PDF) to the Technical Development Fund and was awarded the balance of the award,…
Kidney Week!
I went to Kidney Week in Philly, Nov 13-15. American Society of Nephrology. I spent most of my time in the Bioengineering talks and posters. Here are some highlights. I put the Abstracts pdf on the cloud. Recellularization of Vascular…
Posted in NRG
Adsorption Test of PEG4, IgG and BSA
Discussion: The BSA may have not been fresh enough to give good data, the difference between background and signal are pretty low. The Rhodamine IgG gave better signals but the PEG4 treated SiN is between the untreated SiN and bare…
Urea Clearance: First Animal Study Results
BOTTOM LINE: We had great results from the small number of nanoporous membranes used to clear urea from Sprague-Dawley rats. We are clearing Urea better than commercial materials. (see fig) Recap of previous work: First we leaned how to set…
Bonding PDMS to SU-8, from URNano Workshop
This is the method Brian McIntyre developed for the recent URNano Microfluidics Workshop. Based on a polyaddition-based mechanism based on introducing amine groups onto the surface of one material and epoxy groups on another material and enabling the amine–epoxide polyaddition reaction…
Posted in NRG
What is a glomerulus and where is it? How many are there?
The Bowman’s Capsule contains the Glomerulus, these are both part of a nephron of which the kidney has a gazillion. (The real estimate is the each kidney contains a million nephrons) Here are some pics to orient you. These give…
Posted in Knowledge
Sham Dialysis Study
We performed four hours of sham dialysis, using two non-porous nitride membranes. The set-up is described in an earlier post. Blood samples were taken when the animal was received, after one week of the adenine containing diet, then at 1 hour…
Effects of Adenine Containing Diet on Urea Levels in Serum Drawn from Rats
In order to test the efficacy of any dialysis treatment, we need induce uremia in our animal model. We choose to forgo the surgical approach of performing a 5/6 nephrectomy via ligation for the simpler diet based approach. Feeding the…
Posted in NRG
