New microchip captures exosomes, enabling faster and more sensitive lung cancer detection from blood collection
A new method for diagnosing lung cancer by drawing blood is 10 times faster and 14 times more sensitive than previous methods, according to researchers at the University of Michigan.
The microchip developed at UM captures exosomes (small packages released by cells) from plasma and identifies signs of lung cancer.
Once thought to be trash thrown out by cells for purification, researchers have discovered over the past decade that exosomes are small molecules containing proteins, or pieces of DNA and RNA, that are valuable for communication between cells. I discovered that it was a lump. While exosomes from healthy cells send important signals throughout the body, exosomes from cancer cells can help tumors spread by preparing tissues to receive tumor cells before they arrive. Masu.
“Cancer exosomes that leave the tumor microenvironment go out and prepare a kind of soil. Cancer cell seeds then slough off from the tumor and travel through the bloodstream to be planted in the conditioned soil. , it starts to grow,” said Professor Sanitha Nagrath. in Chemical and Biomedical Engineering and co-corresponding author of the study in the journal Matter.
Exosomes carry proteins to both the inner and outer surfaces of the parcel. Like many biomolecules, these surface proteins are chiral, meaning they have a right-handed or left-handed twist, which allows them to interact with light in unique ways.
Cancer exosomes often have mutated surface proteins, meaning that genetic changes have changed the order of the molecules that make up the protein. Mutations subtly change the shape of a protein, thereby changing its chirality.
These differences can be detected through interaction with twisted or circularly polarized light that matches the torsion of the protein. The resonance produces a strong signal that is returned to the photodetector. However, these light signatures are usually weak and difficult to interpret. Additionally, exosomes need to be extracted from blood samples to perform this type of detection. This is difficult because exosomes are small, only 30 to 200 nanometers (one millionth of a millimeter).
To discover them, the research team used twisted, disk-shaped gold nanoparticles (based on a structure first described in a 2022 Nature study) that trap exosomes in their central cavities. Designed. Due to their nearly perfect match in size, shape, and surface chemistry, these cavities reliably trap exosomes.
If it is right-handed, it will resonate strongly with right-handed light, but if the incoming light is left-handed, it will not send much of a signal back. This different response to twisted light is known as circular dichroism.
Proteins on captured exosomes sink into the cavity, and depending on their shape, the strength of the return signal can be strengthened or weakened. Gold cavities studded along the tiny channels of the microfluidic chip captured exosomes from plasma, revealing distinct characteristics between samples provided by healthy study participants and lung cancer patients.
“We had expected that the optical activity of nanoparticles would depend on protein mutations, but we were pleasantly surprised by their high sensitivity. This is because the nanoparticles are all oriented in the same direction within the detection device. ” said Nicholas Kotoff, Irving Langmuir Professor of Chemical Science and Engineering and co-corresponding author of the study.
The microfluidic chip, named CDEXO chip for circular dichroism detection of exosomes, has the potential to distinguish specific lung cancer mutations, allowing doctors to target treatments based on changes in key mutations. It may help determine the law.
The researchers envision that the CDEXO chip will initially be used in parallel with traditional diagnostic methods. As confidence in the technology grows, the chip could be used to screen for other cancers to improve early detection.
“As a next step, we would like to examine most of the known solid tumor variant proteins and understand how their spectral features differ. From here, we would like to examine these spectral differences to differentiate proteins. We can advance technologies that further increase the
Further information: Yoon-Tae Kang et al, Chiroptical detection and mutational analysis of cancer-associated extracellular vesicles using microfluidics with oriented chiral nanoparticles, Matter (2024). DOI: 10.1016/j.matt.2024.09.005
Provided by University of Michigan
Citation: New microchip captures exosomes for faster, more sensitive lung cancer detection from blood draws (October 3, 2024) https://phys.org/news/2024-10-microchip-captures- Retrieved October 6, 2024 from exosomes-faster-sensitive.html
This document is subject to copyright. No part may be reproduced without written permission, except in fair dealing for personal study or research purposes. Content is provided for informational purposes only.