Optical bioimaging revival may be possible by understanding autofluorescence in animal tissues

Imaging techniques, like X-rays, ultrasounds and MRIs, have incalculably advanced modern medicine. As infrared and optical technologies are improving, a new technique of bioimaging via tissue fluorescence is emerging.

In the 1960s, researchers discovered animal tissue fluorescence at visible wavelengths, but this signal was widely regarded as noise that degraded image quality. However, more recently, researchers realized the valuable information encoded in the autofluorescence, which contains clues about the tissues’ health through its molecular structure and content.

Lifante et al. deliver a compressive review of what is currently known about autofluorescence. The researchers provide background information, the physical basis of the underlying phenomenon, and imaging techniques, including a tutorial on how to set up near-infrared autofluorescence experiments.

The researchers hope the paper will spark interest in the interdisciplinary field from those in the medical and in the physical science communities. While autofluorescence is still largely in animal and pre-clinical trials, there is hope it could someday be used in medical applications, such as in eye surgeries and for diagnosing skin cancer.

“There’s still a lot that needs to be investigated,” said author Dirk Ortgies. “Researchers have identified a few compounds responsible for the fluorescence, but there are still a lot of unknowns.”

Given the simplicity and low costs of optical imaging systems, Ortgies hopes interested groups of spectroscopists, physicists, biologists and chemists will be able to make big breakthroughs in the coming years to connect underlying phenomena and identify more molecules responsible for the autofluorescence.

Source: “The role of tissue fluorescence in in vivo optical bioimaging,” by José Lifante, Yingli Shen, Erving Ximendes, Emma Martín Rodríguez, and Dirk H. Ortgies, Journal of Applied Physics (2020). The article can be accessed at https://doi.org/10.1063/5.0021854 .