Visikol’s CEO Michael Johnson, Ph.D. gives an overview of Visikol’s HUREL Micro Liver products and services.
Hello! My name is Michael Johnson and I am the CEO and Co-Founder of Visikol. Today, I will be talking about the HUREL portfolio of micro liver products and services.
Now, before I dive into talking more about the HUREL products and services I wanted to give you a little bit of background about Visikol as a company. Visikol is focused on accelerating the drug discovery and development process by providing pharmaceutical and biotech companies with advanced cell culture models and assay services, as well as imaging services. These are the two pillars of our business, and we’ve worked with 18 of the top 20 pharmaceutical companies in helping them accelerate their drug discovery and development processes, as well as dozens of other small and mid-sized pharmaceutical and biotech companies.
Now the focus of today’s presentation is on advanced cell culture, and advanced cell culture, the objective, is to try and bridge the gap between in vitro studies and ex vivo studies. Ideally, what we would like to do is have in vitro studies mimic what happens within the body at an inexpensive and high throughput so that we can predict what’s going to happen very early on the drug discovery process. But unfortunately, this isn’t always the case, so we are constantly trying to better mimic the body in a dish and develop complex models that can accomplish that task. We, as a company, are focused on liver cell culture models and assays, as well as oncology models and assays. This tends to be about 80-90 percent of the work that we do. In the liver space we have several models that I will talk about that have been developed and validated for various applications, and in the oncology space we also have several models that tend to be confused on immuno-oncology applications, such as the T-Cell infiltration assay that I am showing here. We’re quantifying how T-Cells are infiltrating into a spheroid model of cancer. And then lastly, while we focus a lot on oncology and liver cell culture, we as a company are model agnostic. We’ve developed all sorts of models for custom application and disease states and as a company that works everything from trans wells to ex vivo tissue slices and really can focus on developing custom assays and models for projects based upon a customer specific requirement and are very open to doing that and working hand in hand with our clients.
But, the focus today will be on liver culture assays and models. A really important thing to consider is that there is not a ‘one size fits all’ in vitro model. 3D cell culture, bio-print models, tissue slice models, they’re not going to replace all the other type of models. Every in vitro model has its place because when you look at a model it’s a balance between through put, price, and relevancy. A model can be extremely relevant, such as a tissue slice model, but the price can be quite high and the throughput can be quite low, so depending on your research question there is a specific model that meets those specific criteria. So, depending on what question you’re specifically answering, what your budget is, what your throughput requirement is, how many compounds you’re looking at, and also what types of in vivo recapitulation do you need to actually answer your research question? If you can get by with a very simple model that’s at low cost, why not use that model? So, we are always focusing on this as a company and trying to provide models that meet our client’s specific criteria for their assays.
As a company we have broad spectrum of models, spanning from 2D cell culture, all the way to ex vivo tissue slices of human, rodent, feline, and also canine for use in the liver space. Prior to acquiring HUREL in May of 2021, we were very focused on spheroids, organoids, and tissue slice models. All 3D or tissue slice models that are quite complex, difficult to characterize, and useful for various applications but not all applications. These models tend to have metabolic stability for only a few days to a few weeks, and the phenotypic stability is not as strong as it is in some other models. And this is one of the main reasons that we wanted to acquire HUREL. HUREL, as a company, their services and products were based upon 10 different species of primary hepatocyte 2D models that are extremely stable phenotypically, and also metabolically, for long periods of time. And thus, by adding this portfolio of models to our portfolio, we are now able to provide our clients with the broadest breadth of liver cell culture models in the entire marketplace, from 2D to spheroids to organoids to tissue slices, we have all these different models within our portfolio that we can pull into DMPK studies, looking at non-alcoholic steatohepatitis, looking at fibrosis, looking at immune cell infiltration into liver tissues, and also traditional drug-induced liver injury So we have a very broad portfolio of liver models as a company, and the focus on today’s presentation is on the HUREL micro liver models, which I will get to in a second, but what I am showing here is not every model answers every research question, and it really depends on what that research question is that we are going after before we are going to pick which model we are going to use because it’s not a one-size fits all solution.
The HUREL micro livers which are now part of the Visikol portfolio of models and assays are a 2D liver co-culture system. The process by which we culture these systems is patented and proprietary, but it allows us to keep primary hepatocytes in culture and metabolically and phenotypically stable for over 4 weeks, up to 2 months of time. Which just isn’t something we see with more complex spheroid models and something we don’t see in traditional 2D cell culture. So, it’s a very unique model, but it’s also very well validated. We have over 100 publications using this model for various applications. We sell it as both a product and leverage it as a service, which I’ll get to in a moment. But, as a product it is shipped live and it can be shipped in 12, 24, 48, 96, and 384 well plate formats, ready for use in our assays. And because it’s a standard plate format it is compatible with standard automation and analytical equipment-any imager, any other type of equipment that you use in your lab for plates is compatible with this system. So we don’t have any special fluidic devices, we don’t need any special equipment, this is a standard plate format, and it’s used by most major pharmaceutical companies for various applications.
And as I mentioned, this has been in various publications for lots of different types of applications, we have looked at over 10 species. And you can see here just from a sub-sampling of papers that are out there that they cover a wide range of topics, but the models have been extensively validated by both academia and GO’s and of course the pharmaceutical and biotech industry. It’s also been extensively compared, which I’ll get to in a moment, with other types of 2D and spheroid systems that are in the marketplace today for the applications that I have described here.
The products themselves, there are 10 different species and they’re shipped in a flexible format. So if we want to ship that with multiple species on a single plate, we refer to that as a Zooplate, and that’s something that we are able to easily do. And then when the plates arrive, after about a 4 hour exchange period (a media exchange) we are able to use them right away for our assays. But, the process is very flexible, we ship live right to your lab and you can use them in your assays right away. And like I mentioned before, there is a 4 week, greater than 4 weeks, stability of these, which is really just fantastic compared to most of the other models out there and of course fantastic compared to traditional 2D cell culture models that have been used for years, specifically primary human hepatocytes, which have been the go-to. We are able to get longer metabolic and phenotypic stability with the patented HUREL culturing process.
If we look at the landscape and compare the HUREL models to micropatterned models, spheroids, what we see is that with the HUREL models we have a far higher number of hepatocytes per cell, what this means is that we have much better phenotypic stability and we are much more easily able to see low clearance compounds and what happens to them; how they metabolize, compared to other models where you have 1,000 or 5,000 hepatocytes. This system can go anywhere from 12 to 384 wells and one of the unique things about the HUREL micro livers, which I will get to later, is that we can actually look at hepatitis infection, it sustains it for a long period of time. It is also compatible with seahorse, and for high content imaging it’s compatible with traditional high content imaging approaches. So, it’s very extensible to a lot of different applications, of course DMPK and DILI. But overall, the greater number of hepatocytes in the process allows this to be the most phenotypically and metabolically stable type of liver model in the market.
Like I mentioned previously, the HUREL micro liver models have a very high degree of metabolic competency. And we see here the ability to generate reactive metabolites as exemplified by HUREL’s viability after exposure to hepatotoxicant cyclophosphamide incubated in the absence and presence, respectively, of broad cytochrome p450 inhibitor aminobenzotriazole. And you see that on the right here in this graph, which allows for a high degree of sensitivity and also predictive capability of the model itself.
And I mentioned this as well, previously, by the phenotypic stability of the model has been peer reviewed and we see this for over 30 days. It’s immutable compared to other models that are out there that we have the highest degree of phenotypic stability in the HUREL model platform and this is especially compared to hepatocytes in suspension, in monoculture, in micropatterned arrays, and also in spheroids.
One of the unique things about the HUREL micro liver platform is that we exposed, for example, the human micro liver model to midazolin in the presence of CYP 3A4 rifampin and CYP 3A4 potent inhibitor ketoconazole, which we administer every 24 hours for 72 hours and we remove these, what we see is the micro livers demonstrated a return to basal enzyme activity in a time-dependent manner, which illustrates the dynamic responsiveness and resilience of HUREL micro liver model metabolic competency, which is just incredible. It returns to basal state after we remove these, which really demonstrates the metabolic competency of these models and also their resistance.
And, when we look at this model for DILI prediction and we look at sensitive and specificity as compared to 3D spheroid models and micropatterned co-cultured models, all primary human hepatocytes, what we see is the accuracy and also the specificity and sensitivity of the HUREL micro liver models is significantly higher, as you see here, based on the publications and literature out there in the research space, which is really incredible to see and shows another application of the model.
And then we look at metabolite generation, what we see is based upon a study from a major US pharma company, we show that the predictive capability of the HUREL micro liver models is improved compared to suspension, 2D cell culture, and other approaches that have been traditionally used. Which demonstrates, again, the ability for this model to replicate what’s happening in vitro compared to known in vivo outcomes.
After going through the features of the product itself and some applications and data, I want to touch upon the services that we offer as a company. Visikol operates primarily as a contract research services company, in addition to selling the HUREL products as well as other reagents and kits.
What researchers are able to do is send compounds along to Visikol that we can test in HUREL micro liver plates. We have LCMS capabilities for metabolite generation and ID studies and the HUREL micro liver coculture system is robust and reliable for human in vivo clearance studies, especially slowly metabolized drugs where we can’t see the clearance in other types of models especially suspension primary human hepatocyte models.
The next application that we routinely do is HUREL TOX, this is a simple TOX assay that we do leveraging the system and various types of readouts-we can do imaging based readouts, we can do ATP assays, we can look at albumin, there are various endpoints we can do as a company but again, what’s happening here is clients are sending along to us compounds and we are running those through simple and traditional TOX assays within the HUREL system. We can go from as simple as ATP assays all the way up to looking at high content confocal imaging if needed at high resolution, and everything in between-qPCR, RNA-Seq, ELISAs, we really have a wide array of different endpoints we can look at, but it really depends on what the research question is. We can also add a mechanistic read out to it as well to look at reactive metabolites and cholestatic liability as well. This is a very flexible platform, but essentially we are taking in compounds and testing them in the HUREL plates.
And then lastly for services applications, like I mentioned previously, the HUREL micro liver model is very stable with hepatitis infection. We can keep infection for a long period of time within the model and of course subsequently test therapeutics against hepatitis, which makes it a really robust in vitro platform for this, compared to other systems that are out there. And there are several publications, like the Nature Communications publication you see here, referenced, that we can pull from for looking at Hepatitis and the HUREL micro liver model for various mounted species being used.
And then lastly, for working with HUREL micro liver services and products, these are your main points of contact. The HUREL micro liver team has joined the Visikol team and will be part of the Visikol team going forward, so if you have any questions on the models themselves, ordering the models, setting up your next study, please reach out to the contacts here and if you have any questions don’t hesitate to reach out.