There is a growing body of publications of why 3-D matters in drug discovery and toxicology assays. This table shows important distinctions for single cell assays.
|Morphology||Sheet-like flat and stretched cells in monolayer||Natural shape in spheroid/aggregate structures||20,24,50|
|Proliferation||Often proliferate at a faster rate than in vivo||May proliferate at a faster/slower rate compared to 2D-cultured cells depending on cell type and/or type of 3D model system||17,51|
|Exposure to medium/drugs||Cells in monolayer are equally exposed to nutrients/growth factors/drugs that are distributed in growth medium||Nutrients and growth factors or drugs may not be able to fully penetrate the spheroid, reaching cells near the core||24,52|
|Stage of cell cycle||More cells are likely to be in the same stage of cell cycle due to being equally exposed to medium||Spheroids contain proliferating, quiescent, hypoxic and necrotic cells||18,24,53|
|Gene/protein expression||Often display differential gene and protein expression levels compared to in vivo models||Cells often exhibit gene/protein expression profiles more similar to those in vivo tissue origins||17,40,54|
|Drug sensitivity||Cells often succumb to treatment and drugs appear to be very effective||Cells are often more resistant to treatment compared to those in 2D culture system, often being better predictors of in vivo drug responses||17,33|
From the table, we see, for the most part, the overall advantages of cells in 3-D for generating more in vivo like data. We also see potential issues like: "Nutrients and growth factors or drugs may not be able to fully penetrate the spheroid, reaching cells near the core".
We have resolved penetration issues with our engineered Collagel Hydrogels. We have further enhanced the assays by including multicell assays that even more closely mimic the in vivo environment.
Our Blood Brain Barrier (BBB) Model, for example, includes our:
- Human Brain Microvascular Endothelial Cells
- Human Brain Microvascular Pericytes (HBMVPCs)
- Human Brain Astrocytes (HBA)
These cells are pre-cultured in the engineered gels and cost a fraction of the individual components (see: culturing and assay protocol).
Our intention is for you to generate the most in vivo like data possible.