How does it work?
In vitro goes 3D Several Swiss startups are developing cell tissues in three dimensions. Compared to standard 2D cultures, they offer more reliable testbeds for pharmaceuticals, biocompatible materials and toxicology assessments. Journalist: Daniel Saraga Infografic: ikonaut
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The right mix The growth of pluripotent stem cells extracted from an organ can be stimulated by hormones, e.g., steroids. Then a dditional hormones kickstart the differentiation of stem cells in different tissues, creating a rudimentary ‘miniature organ’ or organoid. Rotation/agitation helps spread the cells to create a 3D structure.
2 Scaffolds to pilot expansion New cells fill cavities formed from scaffolds or other materials, e.g., hydrogels. For tissues to be reimplanted, they must be made of biodegradable materials or be directly fabricated by the cells, like cartilage.
3 3D printing A 3D printer builds the structure layer by layer by adding cells and a liquid to provide oxygen and nutrients.
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The challenges Quality control is hard to ensure, says the tissue engineering specialist Stephanie Mathes of the Zurich University of Applied Sciences. “It’s not easy to image and characterise dynamic three dimensional structures non-destructively. Commonly used methods for 2D cultures cannot simply be transferred”. As blood vessels are usually missing, growth is limited by the accumulation of waste products and the lack of oxygen and nutrients within the structure. Creating artificial blood vessels or mimicking them with microfluidics could help.
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Organs on chips Microfluidic channels connect the cell cultures of different organs, mimicking the exchanges between organs in the body. This will allow for more reliable testing of substances which are processed first by one organ (such as the liver or kidneys) before reaching others. No Swiss startup has yet to commercialise such a product.
Swiss startups Neurix (2011): minibrains
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InSphero (2009): hanging droplets for organoids
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Elanix (2012): connective tissues for transplantation
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Cellec Biotek (2011): bioreactors
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CellSpring (2015): ingredients for scaffold synthesis
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Sun Bioscience (2016): hydrogel scaffolds
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Qgel (2009): 3D tumors
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Regenhu (2007): 3D bioprinters
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Swiss National Science Foundation – Swiss Academies: Horizons No. 110
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