Chinese scientists have reportedly developed a new technique that makes organs transparent while also preserving their structure. The technique, it is claimed, could be used to make highly accurate and vivid images in the future.
This may help overcome decades of research into seeing inside whole organs (like the brain or heart) without having to dissect them. The big challenge is that biological tissues block light (they’re opaque) and they don’t play nicely with fluorescent dyes, which are used to highlight specific cells or molecules.
Existing “clearing” methods do exist to make tissues transparent, but often mess with their structure (stretching, shrinking, or damaging them), and frozen samples can form ice crystals that destroy delicate detail.
To this end, a team including researchers from Beijing Chaoyang Hospital, the First Hospital of Shanxi Medical University, Beijing Qingzhun Medical Technology Company and Fudan University decided to opt for something called ionic liquids to solve the problem.
Making organs transparent
These are solvents that remain liquid below the boiling point of water (212°F/100°C), making them ideal for treating tissues. It “yielded the highest transparency at various wavelengths… compared with other clearing methods, particularly at shorter wavelengths”, the team said in their published paper.
These liquids are able to enter organs, turning them into what is termed an “ionic glassy state.” When in this state, organic tissue becomes transparent, and keeps its original shape and fine structure as they do not expand or shrink.
The ionic liquids also do not form crystals when cooled, making it possible for treated tissues to be kept in cold storage for long periods, too. The process also massively boosts fluorescent dyes, making them glow 2–30 times brighter.
That means even faint signals (like rare proteins or subtle neuron connections) are now visible thanks to the technique. This technique could have enormous ramifications for applications such as 3D imaging, enabling researchers to now map entire organs at the microscopic scale with more accuracy.
This is especially the case as the technique helps preserve functionally important structures within organs. In fact, the team showed this by examining the micro-connectivity of human neurons, even finding differences in impulse control compared to non-human brains.
In theory, the technique could be used on a wide range of organs from brains to spleens, and everything in between.
More work to be done
Looking at the bigger picture, this is a step forward in precision medicine and diagnostics because it lets scientists and doctors study how human organs are wired at an ultra-fine level. It could also be used to help spot disease markers that were previously invisible.
This may potentially guide future AI-driven medical imaging and organ-level disease mapping.
“The innovative tissue transparency solution provides an ‘X-ray vision’ of the internal structures of tissues equipped with a ‘navigation engine’ to manage sample preparation, fluorescent dye staining and 3D reconstruction,” the team explained on a social media post.
Looking ahead, the team will now continue working on the technology, which could help in fields such as precision medicine and intelligent diagnostics.
You can view the study for yourself in the journal Cell.