Whole organs are difficult to study in minute detail, as they have to be sliced into extremely thin sections to map out their interior. CT and magnetic resonance imaging help to an extent, but researchers at the Helmholtz Zentrum München, Ludwig Maximilians University Munich, and Technical University of Munich in Germany have managed to make entire organs, including a human kidney, eye, thyroid, and pig pancreas, transparent and easy to study using a special microscope optimized for the task.
Described in journal Cell, the technique, dubbed SHANEL, not only makes organs transparent but also allows cells to be identified by type and for a computer to use deep learning to analyze and map the cells within a 3D rendering of the organ. The technology has significant implications for studying a variety of diseases, improving our understanding of molecular scale anatomy, and creating new drugs and medical devices.
SHANEL was created because existing techniques to clear tissues are not effective for entire organs because of large amounts of insoluble compounds. “We had to change our approach completely and start from scratch to find new chemicals which can make human organs transparent,” said Shan Zhao, first author of the study, in a press release. The team studied a large selection of possible alternatives and identified a detergent called CHAPS that pokes holes through organs and helps clearing compounds to seep inside.
To identify individual cells within the cleared organs, the team partnered with Miltenyi Biotec, a German company, to create a laser-scanning microscope that can hold a sample as large as a human kidney. A computer algorithm was also created to identify and map the millions of cells that an organ has.
“SHANEL can develop into a key technology for mapping intact human organs in the near future. This would dramatically accelerate our understanding of organs such as the brain, their development and function in health and disease,” added Dr. Ali Ertürk, Director of the Institute for Tissue Engineering and Regenerative Medicine at Helmholtz Zentrum München and also Principal Investigator at the Institute for Stroke and Dementia Research at the hospital of LMU.
The researchers believe that the technology will aid in designing and bioprinting replacement organs and tissues in the not too distant future. Certainly a better understanding of organs at the cellular level will help.
Study in journal Cell: Cellular and Molecular Probing of Intact Human Organs