PhysioMimix^® multi-chip plates

Using open-well plates allows for easy cell seeding, dosing, and sampling. They have the same SBS standard footprint as standard cell culture well-plates which are familiar to researchers.

Our multi-chip plate-based approach enables scalability for higher throughput capabilities, via miniaturization (i.e., the Liver-48 plate versus the Liver-12 plate), without a complete system redesign.

This approach also provides the ability to customize our consumable design to better meet the needs of individual organs/tissues rather than a “one-size fits all” approach.

Additionally, larger scale microtissues are cultured in plates versus micro-scale chips to provide greater assay sensitivity. Higher, or more concentrated volumes of media (ranging from 0.3 up to 1 mL depending on the plate type), can be sampled from each well to screen for screen for a greater number of biomarkers, clinically translatable endpoints, or metabolites for deeper mechanistic insights. Scaffolds and inserts can easily be removed from plates, enabling a full range of -omics and microscopy analysis/sample. These points are explored in more detail in this blog.

Our Multi-chip plates have the same SBS standard footprint as traditional well plates and provide a similar open-well structure to provide an easy transition from 2D culture into perfused 3D Organ-on-a-chip (OOC) culture. Structurally, the plates are composed of multiple layers, the exact number differs/plate however, in general there is: a top plate containing the independent bioreactors/wells, a membrane, and one or two bottom plates driving the fluidics in the top plate. These are all joined together under a determined pressure, specific to each plate, to allow flow to circulate in each well independently via integrated fluid handling pumping to mimic the bloodstream.

To visualize a generalized reconstruction of out plate architecture and integrated fluid handling, please watch the following animation

Fluidic flow recreates physiological exposure to nutrient exchange, re-oxygenation and shear stresses to permit longer duration studies and optimized organ functionality.

Each well within the consumable plates contains integrated fluid handling pumping to mimic blood flow (pulsatile, or continuous) that can be modified by the user to suit the culture conditions that they require. This all-in-one solution removes the laborious elements of traditional chips -the installation and maintenance of tubing, the requirement for expensive durable pumps and flow regulators. Additionally, the design eliminates the need for durable element sterilization since the cells and their media remain contained within a pre-sterilized single-use consumable.

Dependent on the organ, or tissue, the PhysoMimix OOC system can be programmed to provide flow that is strong and pulsatile, or slow and steady. Many pumps used in OOC systems produce pulsatile flow, which is great if you want to make an artery. The trick if you want to model other organs, such as the liver which has a much steadier flow, is to damp out those pulses.

We use a proprietary design of dampener in our PhysioMimix OOC Systems where consistent flow velocity and shear are desired. The dampening system itself consists of a semi-closed chamber between pump and tissue, a filter or flow restriction controls egress and forces a small build-up of fluidic pressure. A flexible membrane maintains this pressure between pump strokes and absorbs excess pressure during pump strokes. In this way, the extreme stop-start energy of a pulsatile flow is evened out with time.

We avoid the use of Polydimethylsiloxane (PDMS) in our Multi-Chip consumable plates. Although this polymer is widely used, it has limitations. PDMS is a very cheap and easy to use material that is well-suited to small-scale manufacture. It can be turned into a very thin membrane that is great for imaging. Because of this, it is frequently used – even within some Organ-on-a-chip (OOC) technologies.

Unfortunately, PDMS has very high non-specific binding properties, which poses a challenge for applications where drugs or other chemicals are being tested. Customers report that up to 70% of drugs can become bound to the plastic, which impacts data accuracy. It is possible to saturate PDMS plasticware ahead of experiments, however this isn’t ideal as adds more complexity with respect to assay set up and poses a contamination risk. When developing our PhysioMimix OOC Systems and their Multi-chip consumable plates, we decided to move away from PDMS and use Cyclic Olefin Copolymer (COC) instead. For cell culture applications, COC, is currently one of the most inert materials in the market. COC offers one of the lowest non-specific binding properties and is therefore suitable for assessing therapeutic compounds’ pharmacokinetic and pharmacodynamic properties, although we advise performing exploratory studies to check for non-specific binding should there be concerns.

Please read the following references to learn more: van Midwoud et al, 2012, Tsamandouras et al., 2017, McAleer et al, 2019.

By following standard laboratory operating procedures (SOPs) and good aseptic techniques using a microbiological biosafety cabinet. PhysioMimix Multi-chip plates have standard-fitting cell-culture lids, which means they remain sterile in the incubator for the duration of the experiment when good laboratory practices are followed. The pneumatic connection (between PhysioMimix controller and Multi-chip plates), that creates fluidic flow within the cultures is not exposed to the environment.

Yes, we don’t believe in a one size fits all approach. It is important to create an ideal microenvironment that is optimized for each organ model/tissue type. This includes thoughts surrounding the design of the scaffold, any coatings used, the materials, flow through the scaffold, media and many more factors. For example, the material that we use for our liver scaffolds is collagen-coated polystyrene, which is similar to the material used for tissue culture plates but optimized for liver cell culture.

In short, our Multi-chip plates have been specifically designed around recapitulating organotypic pathophysiology, phenotype and function. We don’t believe that a one-size fits all approach works for all tissue types and therefore we have purpose designed a range of plates.

Liver-12 and -48 plates are, as their name suggests, designed for modeling the liver. These plates provide a perfused 3D environment for hepatocytes, and other hepatic cells (e.g., non-parenchymal cells), to grow and form microtissues. We have shown that the microtissues formed are highly functional and viable over several days.

Our Barrier plates are ideal for modeling physiological barriers that occur in e.g., the gut or lung. Cells can be cultured on the apical site and/or basolateral side of a Transwell® insert. The individual micropump in each well provides continuous basolateral perfusion.

Dual-organ plates offer two compartments for culturing two organs such as gut/liver, or lung/liver. The PhysioMimix controller provides a wide range of options to adjust both inter- and intra-organ flow rates and the type of flow (pulsatile versus continual) in each chamber and between the chambers. A common media capable of supporting the health and function of both organ types is required for use with these plates.

For a detailed explanation, please watch this short on-demand webinar, or the following animations PhysioMimix Multi-organ System, PhysioMimix Single-organ System

Yes, our Multi-chip plates are sealed in individual bags post-manufacture and gamma-irradiated to provide a sterile environment. The irradiation process results in a plate color change to green for assurance before starting an experiment.

The Transwells^® within Dual-organ plates and Barrier plates can easily be transferred to a standard well-plate for microscopy throughout an experiment and returned for subsequent culture.

At the end of experiments, Liver scaffolds or Transwells can be removed from Multi-chip consumable plates and the microtissues processed ahead of microscopic analysis. it is possible to perform various imaging techniques (from basic brightfield to confocal immunofluorescence or TEM) on the microtissue when taking down the experiment.

PhysioMimix OOC Systems are not currently compatible with true live tissue imaging as the pneumatics that deliver fluidic flow are built into the bottom the plates. We compromised on this capability to deliver physiologically-relevant and organ-specific flow perfusion– which enhances organotypic microtissue performance and provides greater culture longevity. Our all-in-one design has additional benefits as it removes the laborious elements of traditional chips -the installation and maintenance of tubing, the requirement for expensive durable pumps and flow regulators. Additionally, the design negates the need for durable element sterilization since the cells and their media remain contained within a pre-sterilized single-use consumable.

Additionally, because we chose to use COC over PDMS for our consumable design, our systems are perfectly set up for assays that require accuracy in defining drug efficacy, ADME parameters, or toxic dose (see FAQ above about minimizing non-specific binding. High content data can be extracted from large volumes of recoverable media and microtissue, the latter of which is large enough to divide up for microscopy, or for -omics analysis to derive deep mechanistic insights.

Where live cell imaging is required, there are alternative chip-based technologies that offer this capability, with the caveat that PDMS plasticware is frequently used and data output/sample volumes may be reduced.

Our PhysioMimix OOC Systems allows for the easy removal of any tissues for microscopic or -omics analysis as demonstrated in the following animated videos PhysioMimix Multi-organ System, PhysioMimix Single-organ System.

Tools supplied with the Dual-organ, Liver-12 & -48 plates easily recover 3D liver microtissues. When working with Barrier plates, we use forceps to remove Transwell® inserts from the plate. 3D-like barriers tissue are subsequently recovered by cutting out the Transwell® membrane. Tissues can be fixed using your preferred fixative protocol (we use a standard 4% paraformaldehyde (PFA) fixing protocol with slightly longer incubation period), prior to embedding or staining using optimized standard protocols, or they can be used for -omics analysis by extracting genetic material.

Cell seeding using PhysioMimix is straightforward. Our familiar plate-based design provides easy access to each well of our Multi-chip plates. Cell seeding protocols vary slightly, depending on the predictive human model that you are working with, and the plate you are using. We provide users with detailed protocols for the validated models and applications in our portfolio as part of our support cover.

Like in any standard cell culture experiment, media is changed regularly (every 2 to 3 days depending on the experimental plan) using standard P1000, or multi-channel pipettes (for Liver-48 plates) and tips in a Microbiological Biosafety Cabinet. Whether you want to trigger a disease or add a drug, the agent/ molecule is added to the culture media and refreshed at every media change. For experiments requiring a longer incubation time, such as low clearance compounds or time courses, the volume of media can be increased to suit longer incubation periods, following the plates maximum volume requirements supplied in the Instruction For Use (IFU) manual – for example 4 to 5 days.