Super-Efficient Laser Light Allows Accurate Detection of Nanoscale Extracellular Vesicles, Revolutionizes Cancer Diagnosis and Treatment

Regarding cancer diagnosis, scientists aim to achieve rapid, sensitive, and specific detection of biological particles containing information about the original cell. In a recent study, researchers claim that detecting nanoparticles within five minutes is now possible.

Extracellular Vesicles as Biomarkers

Biological cells, such as human cells, comprise different vesicle structures like lysosomes, autophagosomes, and peroxisomes. Cells communicate with each other by releasing signaling molecules like lipids, proteins, and nucleic acids. The cells pack These signaling molecules in extracellular vesicles to prevent rapid degradation and escape immune surveillance, resulting in local and long-distance intercellular communication.

Extracellular vesicles refer to a cluster of lipid-bound vesicles secreted by cells into the extracellular space. This heterogeneous group of cell-derived membranous structures comprises exosomes from the endosomal system and microvesicles from the plasma membrane. The possibility of isolating extracellular vesicles from various biofluids makes them valuable biomarkers to be analyzed for the diagnosis and prognosis of different medical conditions.

Nanoscale EVs, such as exosomes, play significant roles in intercellular communication. They provide information regarding the cell of origin through the cargo of nucleic acids and proteins, both on their surface and within. They have also gained attention as biomarkers for diseases and drug delivery capsules. This is because they contain microRNAs, mRNAs, and proteins from their cells of origin.

The rapid and sensitive detection of nanoscale EVs from trace samples is important for early diagnosis of intractable diseases like Alzheimer's and cancer. However, extracting nanoscale EVs from cell culture media has become challenging since it requires a complex and time-consuming ultracentrifugation process.

Breakthrough in EV Detection

At Osaka Metropolitan University, scientists utilized laser light's power to accelerate the reaction between nanoscale EVs obtained from cancer cells and antibody-modified microparticles. Led by Assistant Director Professor Ikuhiko Nakase, Deputy Director Associate Professor Shiho Tokonami, and Director Professor Takuya Iida from the Research Institute for Light-induced Acceleration System (RILACS), the research team designed an innovative method for ultrafast and ultrasensitive measurement of biological nanoparticles.

The researchers analyzed the three-dimensional structure of the resulting aggregates using a controlled microflow with three-dimensional analysis by confocal microscopy. As a result, they demonstrated the ability to measure approximately 1,000 - 10,000 nanoscale EVs contained in a 500 nL sample within five minutes. The method also shows the ability to distinguish multiple membrane proteins.

From the result of their experiment, the team was able to attain specific detection of EVs secreted from living cancer cell lines with high linearity without going through an ultracentrifugation process that can take several hours. In addition to this, experts can also control the detection range by adjusting the action range of optical force with the use of a defocused laser. According to Professor Iida, this breakthrough offers a method for ultrafast and ultrasensitive quantitative measurement of biological nanoparticles, opening the doors for early diagnosis of a broad range of diseases.