Advanced imaging technology unlocks exosome potential for disease diagnosis

Tiny particles released by most human cells may be promising targets for diagnosis and treatment of an array of diseases from cancer to Alzheimer's, but scientists have struggled to see them and study them in detail. Now, these particles, or exosomes, are about to be seen in a whole new light – under a new imaging technology being developed in the lab of Wei Chuan Shih, professor of electrical and computer engineering at UH. 

The new technology, supported by a $1.7 million grant from the National Institutes of Health, will be able to examine exosomes one at a time, measuring their features to pinpoint which would be good drug targets. 

It is an enormous task

Inside the human body, a veritable cellular highway exists with 37 trillion cells moving about, keeping us alive, turning food into energy, repairing what needs mending and fighting off predators that try to destroy us. Most of the cells expel tiny exosomes, a type of extracellular vesicle, full of the mysterious biological ingredients that make up the cell itself. 

Small extracellular vesicles and exosomes are known to play important roles in a variety of basic science and applied research fields such as cancer biology, neurological disorders, regenerative medicine, and dermatology. Exosomes are also heavily pursued for various diagnostic and therapeutic applications such as liquid biopsy and drug delivery." 

Wei Chuan Shih, professor of electrical and computer engineering at UH

But there's a roadblock 

Current methods of analyzing exosomes have many limitations such as inadequate sensitivity and specificity, insufficient resolution for single exosome profiling, demanding sample volume, and are heavily reliant on DNA amplification and sequencing techniques. 

Then there's the multitude of steps involving purification, isolation, concentration, and sophisticated labeling. These barriers have hampered the advances in exosome-centric basic and applied research and technology development. 

"To address such an unmet need, we are developing an Integrated Nanophotonic Imaging and Spectroscopy Technology (INSPECT) for scalable, multi-parametric single exosome analysis," said Shih. 

Basically, it uses advanced lighting at nanoscale to review the images and analyze different pieces of information at the same time. 

The technology is based on Shih's previous work in which he demonstrated three well-known nanoplasmonic enhancing mechanisms that detects when molecules bind to a surface, makes fluorescent signals brighter and produces the chemical recipe of the particles. 

"These three techniques are highly complementary and can provide strong synergy in acquiring structural as well as compositional/molecular information from individual exosomes," said Shih. "While this is a single-investigator award, I look forward to collaborating with researchers interested in extracellular vesicles and exosomes, as the NIH-funded effort aims to develop new technologies to unlock their potential."