Applications

3D models increasingly contain multiple cell types to more closely replicate physiological systems, e g:

• Hepatocytes plus Kupffer cells>>> hepatotoxicity
• Neurons plus glial cells/microglia>>>>”mini brains”

In addition, tumor cells can be introduced to produce a disease model, eg glioblastoma cells  introduced into a minibrain to produce a  Glioblastoma model.

With SpheroMatrices® it is possible to visualize  the cellular arrangement/organization of 3D models.

Case study: Using a SpheroMatrices microTMA,  we were able to visualize and measure the growth of tumours within the “host” organoid in the presence and absence of cytotoxic drugs in an iPSC  minibrain model seeded with glioblastoma cells (Scientific Reports, 2019).

With SpheroMatrices, it is possible to both visualize and quantify on/off target events with new chemical entitities (NCEs) in 3D microtissues, using immunostaining and  image analysis.

Assessing target engagement can be challenging, particularly in the absence of a unique enzymatic readout. Using the microTMA  and custom IF/IHC/ RNAscope assays, we can assess the ability of target-specific antibodies find their targets in the presence and absence of competing ligands.

As the SpheroMatrices microTMA is made with fixed tissues, microTMA slides can be subjected to repeated cycles of Heat-induced Epitope Retrieval (HIER), to recover antigen reactivity without impacting upon the integrity of the tissue.

As a result, with current multiplexing protocols, it is possible to stain for up to 6 tissue biomarkers across all treatment groups simultaneously providing a powerful tool for visualising:

• Target expression
• Spatial relationships
• Interactions between cell populations
• Immune cell infiltration,

making SpheroMatrices a powerful platform for the study of new anti-tumor drugs in  3D tumor/PDX model experiments.

The complexity of the immune response makes it challenging to investigate new immuno-therapeutics; however 3D microtissues offer new opportunities for modelling parts of the response.

When immune cells are co-cultured with 3D models, they can be observed infiltrating the microtissue.

With SpheroMatrices microTMA technology, we can stain for cell surface markers for different immune cell types (e.g. T cells, NK cells), making it possible to visualize alterations in spatial relationships and interactions between cell populations within the model in response to drug/chemical treatments.

3D liver human spheroid cultures can be stably cultured for several weeks, making them suitable in vitro models for toxicogenomic studies.

Using human and rat liver microtissues treated with phenobarbital, MicroMatrices (www.micromatrices.com)  performed transcriptomics analyses on laser dissected microtissues from a microTMA slide  (“Cross-species comparison of CAR-mediated procarcinogenic key events in a 3D liver microtissue model”),  demonstrating both the utility of microtissues to recapitulate mechanistic events observed in vivo, and the utility of SpheroMatrices technolgies for mechanistic studies.

The SpheroMatrices microTMA generates serial sections from a single experiment, providing a highly efficient platform for multiplexing phenotypic & genomic analyses for in vitro safety testing in human-relevant microphysiological systems.

Following the identification of lead compounds, analog compounds of promising candidates are assessed for a range of characteristics including target  affinity/selectivity.

As discussed, with SpheroMatrices TMA technology it is possible to visualize and quantify on/off target events.

The microTMA system captures an entire 96 well plate experiment, which might contain 4 or 5 analogous treatments, in a single array. As each array can yield 10 or more replicate slides, SpheroMatrices offers an efficient and versatile tool for comparing drug analogs.

Cells grown in 3D more closely model cellular responses and functions observed in vivo than cells grown in 2D.  For example, the extra dimensionality of 3D cultures affects the signalling from the outside to the inside of cells, and ultimately influences gene expression and cellular behaviour. This makes 3D models better for biomarker discovery and  identification .

The SpheroMatrices TMA platform is an extremely useful tool for this purpose as it is possible to identify, localize, and compare multiple intrinsic  biomarkers across treatment groups within a 96 well plate experiment on a single slide.