Peddie EXP Summer 2018

Over the past two weeks, I finished processing, loading, and evaluating my final canine tail and rat tail IVD samples that I received from the vet school. Then, I used my collection of IVD load study media plates and tissue digest plates to run several different types of fluorescence and absorbance-based assays. The quantitative data gathered from the plate reader was then run through a T-Test to identify the statistically significant values. I also participated in my last study day at the Vet Med Diagnostic Lab. The vet school delivered three rat tails and three canine tails at the beginning of week 8 after their biweekly necropsy. These were my 8th set of canine/rat tail IVD samples and I breezed through the harvest and loading procedures due to my mastery of the protocols. I harvested 6 IVDs from each of the rat tails and 9 IVDs from each of the canine tails with the rongeurs and bone cutters. All of the muscle and fat surrounding the vertebral column was stripped and the IVDs w...

Charlie updated me with some news about the human islets – it looks like the next shipment will be arriving on August 14 th , exactly one day after I leave SF… But on the bright side, he and Ana will be able to suspend the islets in a hydrogel and load that gel into my hollow fiber cartridges for insulin-glucose response testing. I’m looking forward to seeing some results in the next few weeks, even though I won’t be able to complete the final part of the study. I’ve also done a lot of deeper CAD work with the backside structures of the iBAP device itself. As a reminder, the device faces some clotting issues because fibrinogen, a clotting protein, is small enough to pass through the silicon membranes. If the flow is stagnant, then this fibrinogen attaches to the internal walls of the device and settles down to begin coagulating, shown in the blue (slower flow velocity) areas of the following image.  If the flow rate and shear stress along the walls is high enoug...

The past two weeks at the MOI have been packed full of 12 hour days due to the influx of rat and canine models from the vet school. The vet school students practiced their necropsy techniques and sent over 8 rat models at the beginning of week 6 and 3 canine tails on week 7. With the arrival of these new rat models and canine tissues, I had to harvest all of the available tail IVDs, place them in the flexcell plates and vacuum system, culture them under load for 6 days each, and perform media changes and the end-of-culture procedure. The lab also had an MOI organized study day this week in which I was one of the first five people in the world to evaluate a successful ACL to ACL allograft! I received the 8 rat tail models on Monday of Week 6 and immediately started the harvesting procedure. All of the harvesting procedures for IVDs have to be performed sterilely, so I had to lay sterile mats in the hood, gather all the necessary sterile equipment, and use sterile gloves. I used a sc...

This week, most of the veterinarians and orthopaedic surgeons took a much-needed week off due to the hectic surgery days that occurred last week. I continued to work on my IVD degeneration disease load study with sections of canine cervical and lumbar spine. Furthermore, I monitored the eleven canine models that underwent full hip arthroplasties last week to make sure they were doing well during their post-op recovery period. I received sections of canine cervical and lumbar spine from the veterinary medical diagnostic lab (VMDL) after a complete necropsy. This was my first time harvesting full sized canine IVDs out of the spine, which proved to be quite a different process than removing tail IVDs. Instead of using hemostats and bone-cutting forceps, I used a sterile bandsaw used specifically in the lab for removing full canine IVDs. The harvesting process included trimming the tissue and muscle that surrounded the spinal column in order to reveal where the IVDs were located. Then,...

My fourth week at the Missouri Orthopaedic Institute has been the busiest and most action-packed of them all! Surgery days, end-of-culture days, harvest days, and an immense number of media changes made for a truly unforgettable week. Although I have yet to receive any knee joint tissues, I have been working extensively with my rat tail IVD "Trucker" model that I mentioned in my previous blog. After harvest, I cultured the IVDs under a load that simulated the compression and vibration that the spinal column experiences while driving in an 18-wheeler. The IVDs were cultured in Flexcell plates and vices that connect to a vacuum system, which forces a rubber membrane to compress the IVD against a plastic insert. I developed and programmed a 6-day regimen that followed legal commercial driving limits and allowed for a 1 Hz/.25/.50 MPa pulsating load in order to accurately simulate the vibrations and jostling that occurs while driving. All three of the plates were filled with a...

Hey everyone! It’s been a while since my last blog post – I’ll chalk that up to being so busy these past couple of weeks with lab work and other things. Going into my fourth week at the Roy lab, it’s hard to believe that my time here is flying by so quickly already, but here we are.  After my first week at the lab, I started working on my independent project. As I mentioned before, my lab works with creating bioartificial organ devices, specifically an implantable artificial pancreas. Once implanted, the patients blood goes through the device and through diffusion, an ultrafiltrate is produced by passing the blood across a silicon nanopore membrane (SNM). (here’s a picture of one of those silicon nanopore membranes I keep talking about - the rainbow is from refracted light, not actual coloring)  This ultrafiltrate is mostly just blood plasma, but it has a couple of key ingredients: dissolved oxygen, glucose, and other nutrients. The ultrafiltrate is then fed thro...

As mentioned in my previous blog, I have been awaiting ligament, menisci, and cartilage tissue from a canine or human knee joint for (interleukin) IL-1B tissue culture. IL-1B is an inflammatory cytokine that has been proven to increase rates of tissue degeneration and osteoarthritis development in the Thompson Lab. Dr. Stoker wants me to experiment with different types of knee tissues in a co-culture with varying levels of this cytokine to determine its effects on the entire knee joint. This co-culture uses an insert permeable to the media to separate the two tissue samples from physical contact, while allowing them to share the same media. This creates an extremely accurate model for knee tissues in their native environment due to their exposure to the same synovial fluid in the joint. This model would then be treated with the IL-1B and cultured for 21 days. During these 21 days, the media would be collected every three days for biomarker evaluation at the end of the stu...