CHICAGO, June 20 (Xinhua) -- A new microscope system that uses tailored pulses of light to image with multiple wavelengths can image living tissue in real time and in molecular detail, without any chemicals or dyes, according to researchers at the University of Illinois (UI).
The simultaneous label-free autofluorescence multi-harmonic (SLAM) microscopy differs from standard tissue pathology in several ways: it is used on living tissue inside a living being, giving it the potential to be used for clinical diagnosis or to guide surgery in the operating room; it uses no dyes or chemicals, only light.
Meanwhile, SLAM microscopy simultaneously collects multiple contrasts from cells and tissues, capturing molecular-level details and dynamics such as metabolism.
In the study, UI researchers looked at mammary tumors in rats, along with the surrounding tissue environment. Thanks to the simultaneous data, they were able to observe the range of dynamics as the tumors progressed and how different processes interacted.
The researchers saw that the cells near the tumor had differences in metabolism and morphology, indicating that the cells had been recruited by the cancer.
In addition, they observed surrounding tissues creating infrastructure to support the tumor, such as collagen and blood vessels. They also saw communication between the tumor cells and the surrounding cells in the form of vesicles, tiny transport packages released by cells and absorbed by other cells.
"Previous work has shown that tumor cells release vesicles to lure the surrounding cells to support them," said UI graduate student Sixian You, first author of the research. "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."
"SLAM allows us to have a comprehensive picture of this ever-evolving tumor microenvironment at subcellular, molecular and metabolic levels in living animals and human tissue. Monitoring that process can help us better understand cancer progression, and in the future could lead to better diagnosis of how advanced a tumor is, and better therapeutic approaches aimed at halting the progression," said You.
This technology may 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 study leader Stephen Boppart, a UI professor of bioengineering and electrical and computer engineering.
In the next step, UI researchers will use SLAM microscopy to compare healthy tissue and cancer tissue in both rats and humans, focusing particularly on vesicle activity and how it relates to cancer aggressiveness. They are also working to make portable versions of the SLAM microscope that could be used clinically.
The research, released on UI website Wednesday, has been published in the journal Nature Communications.