Researchers at the University of Illinois have developed a new microscopy technique that can image living tissue in real time, without the need for chemical stains or dyes. The technique can achieve significant detail, such as allowing researchers to see the movement of vesicles, which are tiny transport packages, between cells. This approach could be used during surgical procedures to assess tissues of interest, and also has significant potential in tissue pathology, diagnostics, and disease monitoring applications.
“The way we have been removing, processing, and staining tissue for diagnosing diseases has been practiced the same way for over a century,” said Stephen Boppart, a researcher involved in the study. “With advances in microscopy techniques such as ours, we hope to change the way we detect, visualize and monitor diseases that will lead to better diagnosis, treatments, and outcomes.”
The system uses pulses of light at different wavelengths to image various tissue features simultaneously, and the researchers have called it “simultaneous label-free autofluorescence multi-harmonic microscopy” (SLAM).
Unlike conventional microscopy techniques, SLAM requires no dyes or chemical stains. Tissue staining adds a layer of complexity and time to conventional microscopy, and can disrupt the tissue of interest. SLAM can also be used to image living tissues, suggesting that it could help to guide surgeries, or provide a greater level of detail during diagnostic investigations.
So far, the researchers have used the technique to investigate tumor progression in rats. They were able to view the living tissue in unprecedented detail, and observed communication between cells, as tiny vesicles released by tumor cells were absorbed by other cells.
“Previous work has shown that tumor cells release vesicles to lure the surrounding cells to support them,” said Sixian You, another researcher involved in the study. “Then the cells that have been recruited release their own vesicles to go back to the tumor. It’s a vicious cycle. It’s very different from the activity we see in our control samples with healthy tissue. The capability to see the dynamics of all these important players in authentic tumor environments can help shed light on this mysterious but critical process.”
Currently, the research team is developing a portable version of the SLAM device, so that it is more clinically translatable. “We believe that this technology will open the possibility of complementing, or even replacing, standard histopathology processing, which is time- and labor-intensive and can only be done on removed, fixed, dead tissue,” said Boppart.
See a living tissue in motion in this video:
Study in Nature Communications: Intravital imaging by simultaneous label-free autofluorescence-multiharmonic microscopy…