Culturing cells has always been an important tool for biological research and drug discovery. Although most studies are based on 2D (two-dimensional) cell cultures, 3D (three-dimensional) cell cultures better mimic in vivo conditions, making them one of the fastest-growing experimental approaches in life sciences. Read Medilink EM Member Aurelia Bioscience’s blog below to learn more about 3D techniques and their advantages in cell-based screening.
Cell-Based Assays:
Cell-based assays use live cells to gather information on therapeutic candidates. The accepted dogma is that they offer a biologically relevant surrogate system to predict the response of a drug on an organism.
Historically, cell-based assays used only two-dimensional monolayered cells cultured on flat and rigid substrates. Although 2D cell cultures are still very useful in providing information on biological targets and pathways, their limitations are being recognised. Since almost all cells in the in vivo environment are surrounded by other cells within an extracellular matrix three-dimensionally, there is an increasing demand for 3D techniques that are more reflective of in vivo cellular responses.
3D Cell Culture:
3D cell cultures are artificially created environments in which biological cells are permitted to grow or interact with their surroundings in all three dimensions. There is a growing body of literature that suggests that cells in 3D culture differ morphologically and physiologically from those in 2D. The additional dimensionality of 3D culture is a crucial feature leading to differences in cellular responses from the two formats. It not only influences the spatial organisation of the cell surface receptors engaged in interactions with surrounding cells, but also induces physical constraints on the cells. The close proximity of cells in the 3D environment enables surface adhesion molecules and surface receptors on one cell to bind to similar molecules and receptors on adjacent cells. This coupling maximises cell-to-cell communication and signalling that is crucial for cell function. The spatial and physical aspects affect both the signal transduction from the outside to the inside of cells and through paracrine and autocrine mechanisms, ultimately influencing gene expression and cellular behaviour.
There are various approaches available to culture cells into 3D structures. These approaches can be grouped into two main categories: scaffold-based techniques, e.g. hydrogels, fibrous and porous scaffolds; and non-scaffold-based techniques, e.g. spheroids, hanging drop microplates and microfluidic 3D cell culture.
Get in touch with the Aurelia Bioscience team to learn more about their work on spheroids.
[box type=”shadow” align=”aligncenter” class=”” width=””]3D cell culture has been around for longer than we might think!
In 1907, Ross Granville Harrison adapted the hanging drop method from bacteriology to develop the first 3D tissue culture system using frog embryogenic cells. This allowed for further studies in embryology as well as experimental improvements in oncology, virology and genetics to name a few.[/box]
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U-87 MG cell spheroid stained with Hoechst, Calcein AM and Propidium Iodide stains and imaged with CellInsight™ CX5 High Content Screening (HCS) Platform. The spheroid was seeded at 1000 cells and cultured in 384 well Costar ULA spheroid plates for 7 days. |
3D Micro- Scaffold:
Aurelia Bioscience has developed a 3D micro-scaffold system from electrospun material (Electrospinning Company, Harwell, Oxford, UK) that can be used in conjunction with well plates for higher throughput screening (HTS). Electrospun material mimics the natural extracellular matrix and provides an ideal substrate for adherent cells. They have re-engineered electrospun material to form micro-scaffold islands on to which we seed, grow and differentiate cells prior to performing more conventional assays in well plates. Cells grow on, around and into the material, forming a micro-island of adherent cells that are effectively “in solution”. The incorporation of iron nano-particles into the fibres during manufacture results in micro-scaffolds that can be physically manipulated using magnetism.
Unlike other 3D cell biology systems, this technique was developed to offer the potential to accommodate any cell type in any assay at any throughput. 3D micro-scaffolds have proven to be compatible with all common biological plate-based assay types including luminescence, fluorescence, high content imaging and real-time kinetic studies. This technology, if coupled with iPSC’s (induced pluripotent stem cells), differentiated stem cells or human-derived primary cells further enhances a phenotypic approach to drug discovery, introducing a better physiological environment to a cell-based HTS system.
Click here to find out more about this novel technique.
Click here to watch a short video on the subject.
If you are using 3D cell culture models and would like to discuss your project with the experienced team of scientists at Aurelia, please click here
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Environmental SEM image of A549 cells 4 days post-seeding onto scaffolds. The image above shows two scaffolds at 90 degrees to each other, populated with cells next to an unseeded scaffold. |