Atomic Layering for Pharmaceutical Applications: Thermostable, Timed Released, Single-Shot Vaccines

Jessica Rachut – VitriVax


Vaccines provide unique benefits for human health, but their broad use often is limited by their ability to maintain thermostability and the need to administer multiple doses. Using Atomic layer deposition (ALD), we are able to take our Thermostable Antigen and Adjuvant (ALTA) technology platform and enable thermostable, single-shot vaccines across a broad range of indications, while maintaining or potentially even enhancing the immune response of vaccines. ALTA can be applied to a wide variety of vaccine antigens and adjuvants to protect against thermal and chemical degradation and enable controlled release, incorporating prime doses + additional booster doses in a single-shot administration. These technologies may also facilitate co-formulation of multiple otherwise incompatible antigens in a single injection.


0:00:01 Hi everyone. My name is Jessica Rauchet and I am the laboratory manager and senior research associate
0:00:07 at VitraVax. I just want to thank forge for the invitation to the summit. I am just so happy to be
0:00:15 included with such an amazing group of scientists. Um So today I’m going to be talking about atomic
0:00:20 layering for pharmaceutical applications, where I will be specifically talking about thermo stable,
0:00:26 time released, single shot vaccines. I know this is a virtual event, so feel free to write down your
0:00:32 questions as I go and reach out to me after the presentation. Um so just to give you a little bit of
0:00:38 background about myself, I’m originally from pennsylvania, born and raised. Um I earned my Bachelor
0:00:45 of Science and biotechnology with a minor in biochemistry from Shippensburg University and then I
0:00:50 went on to earn my master’s and biotechnology from johns Hopkins University. I have a background in
0:00:56 infectious diseases, translational cancer research, personalized medicine, asset development and the
0:01:02 vaccine development. I also worked across various sectors in government, academia and industry. Um
0:01:08 But enough about me, I’d like to spend this talk discussing the Vitra vex technology platform
0:01:13 creating thermo stable time released single shot vaccines. So if we go on to the next slide um So
0:01:23 Vitra Vac uses spray dried formulation um consisting of antigens and achievements along with disa
0:01:29 Carides. This combination allows us to obtain a higher glass transition temperature for the
0:01:36 particles as well as former glassy matrix to provide thermo stable micro particles. Um So after
0:01:43 spray drying using atomic layer deposition, we can coat these and again regiment containing micro
0:01:48 particles with a protective metal oxide. Um To provide times released doses, these doses allow for a
0:01:57 boost up to six months after injection, eliminating the need for multiple shots. Basically the L. D.
0:02:04 Layer provides a slow time the release of the particles, but also allows for extra event when using
0:02:10 the aluminum wire.
0:02:15 So if we just kind of dive a little bit deeper into spray drying. I just want to do an overview of
0:02:21 the process for those of you who are unfamiliar with how it works. So we start with the antigens and
0:02:27 the achievement along with the uh sugar formulation. This will form a glass matrix. One spray dried.
0:02:35 The formulation mixture is loaded into a syringe and a syringe pump is used to deliver the
0:02:41 formulation in a needle with heated gas. Here the formulation is atomized by the needle actually
0:02:49 pressing down and dispersing the particle mixture or the mixture itself into particles. So um
0:02:58 basically um it’s exposed to hot air which allows for rapid drying of the droplets in the drying
0:03:05 chamber and then the dry particles can then go on through the cyclone and be collected into a vial.
0:03:11 Um This powder can then farther be dried in preparation for atomic layer deposition.
0:03:22 So once these particles are spray dried, we can actually look at these under a scanning electron
0:03:27 microscopy uh otherwise known as ECM. Um As you can see, there is some variation in these particles
0:03:34 uh but also due to the components in the formulation, the particles can become wrinkled or have
0:03:40 dented appearance. Uh flow cam um is also used to help us determine uh the particle size
0:03:50 distribution of the spray dried particles. Um As you can see a lot of these do fall in the 4-8 range
0:03:59 here. Um And even looking at this ECM, you can you can definitely see these distribution of the of
0:04:08 the sizes. So um obviously when with spray drying comes some challenges as you could see from before.
0:04:17 So, due to the size distribution caused by spray drying, um we take an average particle size of 5-7
0:04:24 microns. As this helps in later applications when we go to coat for atomic layer deposition. Another
0:04:32 challenge comes from the irregular shapes and the surface area of the particles. The wrinkled shape
0:04:37 actually creates higher surface area, so this needs to be accounted for when calculating the amount
0:04:42 of precursor needed for dozing. Um And lastly, the water content in the spray dried particles can
0:04:49 also cause unwanted reactions with the precursors during atomic loitering. So after spray drying,
0:04:55 the particles have about a 5% moisture content. If we were to keep the moisture content at 5%,,
0:05:02 these particles would gain significantly more eliminate due to the reaction between try method,
0:05:07 aluminum and water. Therefore, we further dry down these particles under vacuum to decrease the
0:05:13 moisture content to less than 1%. So um we actually measure this by Karl Fischer titillation and we
0:05:20 just always try to Make sure that we’re under that 1% to prevent that extra wiring that we are not
0:05:27 accounting for.
0:05:34 So um for the atomic layering side of things. I’m not really going to go into a lot of detail
0:05:43 because I know um this is an L. D. Summit so I’m sure you’re going to be hearing a lot about that
0:05:50 process. Um So I’m going to be kind of talking a little bit more about what we do with this process.
0:05:56 So um basically as I said before we use time ethel try meth, aluminum and water as are precursors
0:06:04 also known as T. M. A. Um So due to the high vapor pressure of both the reactant, we can actually
0:06:10 run r A. L. D. Cycles at lower temperatures. This is important when thinking about bio molecule
0:06:17 stability. Another interesting feature about our process is we usually run between 50 and 1000
0:06:24 cycles. So we have a pretty wide range um And we conduct this process in both the fluid eyes bed
0:06:32 reactor and a rotary reactor. Um We don’t use both at the same time but we do have processes for
0:06:39 both. A fluid eyes bed and a rotary. Um The rotary reactor is nice though because we are able to
0:06:46 scale up for an Upwards of 100,000 vaccine doses. So that’s really awesome.
0:06:55 So to give you a little bit more about the fluid eyes bed, uh nitrogen is actually flowing through
0:07:01 the bottom of the system along with the precursors. The flow can be adjusted until the particles are
0:07:07 actually fluid. Ized and then suspended in the chamber. A vibration and or an impactor can also be
0:07:15 used to keep these particles from sticking to the walls of the reactor and everything is done under
0:07:21 vacuums to the precursors can be delivered at low temperatures to accommodate the androgen and
0:07:27 achievement embedded particles. Um The biggest issue though with the fluid ice bed um is what is
0:07:35 considered the Brazilian nut effect, basically due to the size distribution of the particles. When
0:07:42 the powders are agitated in the reactor, it actually causes uh the larger particles to float and
0:07:49 congregate to the top while the smaller particles fall to the bottom. Um This can cause uneven
0:07:54 coding if you are not being careful and conscious while actually coding the powders. Um This is
0:07:59 something that we have seen and we can adjust for that, but it has become an issue before. So we
0:08:07 started moving over to the rotary reactor. So to give you an idea a little bit more about what is
0:08:13 nice about the rotary actor is it allows for rolling of the particles inside the reactor um allowing
0:08:20 for an actual even coding. So um as you can see there is a larger chamber that doesn’t move around
0:08:28 um and then a smaller chamber inside of it, which is actually the reactor chamber that holds the
0:08:33 powder itself. So um this smaller reactor chamber is able to just roll around and that’s what
0:08:43 determines how the powder is actually rolling. Um So we can adjust that speed and direction of it
0:08:51 depending on how we actually want to manipulate the powders themselves. So the idea is that we are
0:09:01 more trying to target a rolling or cascading um kind of effect where we are constantly seeing a
0:09:09 tumble of the sand particles. Um things we want to avoid is something like this over here in the
0:09:16 corner where we’re spinning too fast and the powders are just kind of being stuck to the walls. Um
0:09:23 What else? What also is nice is, you know, we can add in other different vibrations and impact ear’s
0:09:31 to also prevent sticking to the walls. Some powders that we do use can be a little stickier than
0:09:38 wanted, so we can tweak the rotation based on the powder properties.
0:09:47 So just another view of the reactor, this is showing the precursors off to the right there kept out
0:09:52 of the oven to prevent overheating um and then they can be delivered into this bumper chamber here.
0:09:58 So the smaller chamber front here is called a bumper chamber where it allows us to actually dose are
0:10:05 precursors based on a pressure. So um it allows for a lot more consistency when it comes to dosing
0:10:13 and it makes the calculations a little bit easier with the amount that we need to do. Um Because our
0:10:20 temperatures are lower than normal L. D. Reactions. We do increase our purge times to prevent that
0:10:28 CVD build up.
0:10:32 So just to kind of do a little overview of the actual Pandora system. Uh So the writer reactor runs
0:10:40 on the Pandora software system here. I can create recipes and programs and see live graphs for the
0:10:46 temperature and pressures. Um And I can also control all the valves manually. The green shows open
0:10:52 valves and the gray are closed. Mhm. Uh You can control the speed of the rotation and um if you want
0:11:01 you can change the direction like I said before so you can um continue clock with wise and then
0:11:07 maybe do a half turn counterclockwise um and just kind of play around with that, making sure your
0:11:13 powders are not sticking to that actual reactor bed. Um So another thing that’s really nice, there’s
0:11:21 two places that read the temperature um and the same for the pressure. The temperature allows you to
0:11:26 see what the reactor bed is actually at and the oven itself. Um Whereas the pressure gauges show the
0:11:32 pressure in the bumper chamber as well as the reactor chamber. So this is what allows us to dose
0:11:37 based on pressure. So we’re able to dose that smaller chamber and then because of the pressure
0:11:42 difference between the smaller bumper chamber and the actual larger reactor were able to deliver
0:11:47 straight into the reactor for it to react with our actual powder product. Um Again this makes for
0:11:55 very nice things. Another interesting feature is these weight conditions so we can um either do
0:12:02 different weight conditions based on pressures that we’re waiting for, temperatures that we’re
0:12:07 waiting for um and other various features uh which makes it really nice. So if we look at the ECM or
0:12:19 the skinny electron microscopy of the atomic layer, deposition coded spray dried particles, we see
0:12:26 that these particles become a little bit more around. You don’t see as much of the dense, so they’re
0:12:31 much smoother. The flow ability is much better of these particles. Um this specific one over here
0:12:37 has about 250 coats on it. Um And then on the right, you can see our prediction or expected. We
0:12:45 gains based on the amount of aluminum layers that we put on our cycles that we put on. So based on
0:12:54 Calcium nation, we can actually, so calculation heats up the particles to around 950°C to burn off
0:13:02 any salts and organic so that we can assume the weight left is just our aluminum. So we can back
0:13:08 calculate um and determine if the particles received the expected weight gain. So based on the
0:13:15 number of cycles we can expect a certain weight gain and we determine it from there. Um So we have a
0:13:22 nice kind of graft to go off of
0:13:30 another. Look at our particles. We can look under transmission electron microscopy, which is TM.
0:13:36 This allows us to look at the coded particles and see the contrast between the spray dried particle
0:13:41 and the actual aluminum coding. So you can see in this photo here there’s actually a color charge
0:13:48 difference between the particle itself and the actual wiring that’s going on. And then if you look
0:13:55 over on the right here, we can see. We actually used a Fib ECM, which is a focused ion beam, um
0:14:06 scanning electron microscopy. So with this focused ion beam were actually able to cut through the
0:14:12 particles themselves and see the actual layering going on. So um after we cut through, we uh we can
0:14:20 do ECM and then we can see these aluminum wires and actually measure how much aluminum is expected
0:14:27 to be on the outside of the particle. Um so I guess the big question here is what are we actually
0:14:37 doing with these coded and again and adjuvant containing particles?
0:14:45 So the biggest experiments that we’re doing are actually time to release vaccines in mice. So how do
0:14:56 we do that? Basically? We go through all of our steps. We take our formulation with the A given and
0:15:01 an injun containing formulation. We make that into a spray dried powder and then we’re able to coat
0:15:07 that powder. So based on the number of coatings, we can expect a certain release by a certain time.
0:15:14 So using different mixtures of uncoated and coated particles, we can create boost effects so that we
0:15:24 don’t have to do more than one shot. So the idea is that we can get one shot and it’s still getting
0:15:31 those boost effects two weeks later, six weeks later, eight weeks later due to these liar ng using
0:15:40 atomic layer deposition. So it’s really cool that we are able to hopefully eliminate these multiple
0:15:49 shot vaccines and get it down. Get all these vaccines down to a single shot. Um but it’s exciting
0:15:58 new field and I’m excited to be a part of it. So if anyone has any specific questions, feel free to
0:16:06 reach out to me. Um just to kind of quickly go over kind of what the study showed last year, if
0:16:13 anyone has seen, um we published a paper using HPV. Getting it down to a single shop. So in mice we
0:16:22 actually injected them with either coated or uncoated Particles or just their regular vaccine
0:16:30 themselves. And then over the course of 14 weeks we measured the intent or the fluorescence of the
0:16:38 HPV inside of the mice themselves. So we were able to see throughout um using antibodies that we
0:16:46 were able to see um expression. Um 14 weeks out showing that we’re still getting release of these
0:16:55 particles and of these antigens into the body. Um so now we get to see the boost effects of
0:17:03 everything. Um so again, uh questions or comments. Feel free to reach out to me. My name is Jessica
0:17:10 Rocket. Again, I work for Vitra vex. Uh Thanks again to forge nano for inviting me to come speak. Uh
0:17:19 and I hope everyone enjoys the summit. Thanks bye.