What are the latest advancements in three-dimensional cell models—and what does the future hold for these innovative biomedical research tools?
A recent article in Nature highlighted organoids and organs-on-chips, discussed their strengths and weaknesses, and described what’s next for these human-relevant models that may be able to reduce and replace animal experimentation.
Organoids, named “Method of the Year” by Nature Methods in 2017, are complex in vitro models that mimic the structure and function of real tissues and organs. These multicellular stem-cell derived models are formed when stem cells self-assemble and organize into complex 3D structures. Many different organoid models are already available, including models of the liver, kidney, brain, breast and gastrointestinal tract, among others.
Organoids are currently being used to study normal human biology, including basic brain development to identify factors that may contribute to conditions like schizophrenia and autism. They are also being used to better understand complex genetic diseases like cancer and infectious diseases like that caused by the Zika virus.
Researchers are working to ensure that organoids can be developed in such a way that will enable them to be accurately reproduced. This is especially important for applications that need consistency, like the safety and efficacy testing of drugs, chemicals and cosmetics.
One issue with organoids is that they lack an integrated vascular system. This can impair their growth and development into mature and functional tissues, an obstacle that researchers—including those funded by NAVS and IFER—are trying to overcome.
Organs-on-chips are 3D models that are also being developed to simulate tissue and organ-level functionality. These are microfluidic cell culture devices that have channels lined with living cells. Organs-on-chips are designed to mimic the multicellular architecture and biochemical microenvironment seen in vivo. They can incorporate biomechanical features that enable the cells grown within the devices to change shape and respond to physical cues in ways not possible with traditional 2D or 3D cultures.
We continue to learn about researchers linking together organ-on-a-chip devices to create more complex systems. In addition, researchers are working on using cells derived from patients to populate the devices to make them more applicable to personalized medicine.
While some technical challenges remain with both organoids and organs-on-chips, including how to scale up production to meet the demands of research while ensuring that the models maintain the integrity of the tissues they are representing, we are excited to see the scientific community tackling these obstacles. We are optimistic that these in vitro tools will have a significant impact on reducing and replacing animal use in science.