Researchers from the College of Sciences and College of Medicine have developed a quick, easy and cost-effective method to isolate and study exosomes, which can help diagnose diseases such as cancer and Alzheimer鈥檚 earlier.
Exosomes are nano-sized vesicles released by cells that can carry information which contain proteins, DNA and other molecules from the cells that created them. They serve as messengers giving a view of what鈥檚 happening inside the body, which makes them promising tools for early, noninvasive disease detection.
Led by principal investigator Kiminobu Sugaya, professor and head of the neuroscience division at the College of Medicine, and Qun Huo, professor and graduate program director in the Department of Chemistry in the College of Sciences, the team created a streamlined alternative. Their new method uses basic lab tools to collect and concentrate exosomes from cell samples in under an hour. The findings were recently published in the American Chemical Society鈥檚 Applied Bio Materials journal.
鈥淥ur method eliminates the need for ultracentrifugation, precipitation kits or affinity-based labeling,鈥� Huo says. 鈥淚nstead, we use a size-selective filtration and direct optical analysis technique that can isolate and characterize exosomes within a single step. This not only reduces the processing time significantly鈥攆rom hours to minutes鈥攂ut also minimizes sample loss and experimental variability.鈥�
With this form of characterization, the researchers add specific antibodies, which are proteins that bind to target disease-related proteins on the exosomes. If the antibodies find a match, the exosomes cluster, causing a measurable increase in size. This change can be quickly detected using dynamic light scattering (DLS), a light-based measurement technique.
鈥淲e chose DLS not only for its ability to measure particle size distribution rapidly and non-destructively, but also for its sensitivity in detecting molecular interactions,鈥� Huo says. 鈥淭he resulting change in hydrodynamic size, as measured by DLS, serves as a direct indicator of antigen-antibody interaction.鈥�
Hannah Ambrosius, a chemistry doctoral student, worked closely on the study as part of her thesis and shares that she quickly recognized the potential beyond just speeding up the isolation process.
鈥淕iven that exosomes contain specific biomarkers that can be used for disease detection, like cancer, it’s imperative that the exosome is efficiently isolated and purified before further analysis,鈥� Ambrosius says. 鈥淲ith this protocol, we’ve moved on to human samples and have made some very interesting discoveries that we’re excited to soon share with the research community.鈥�
The researchers tested the method on exosomes from three types of cells: human embryotic kidney cells, genetically modified cells with green fluorescent protein and brain cancer stem cells from a patient with glioblastoma. In all three cases, the method successfully isolated the exosomes and identified their surface proteins with great reliability.
鈥淲hile exosome research is often associated with neurodegenerative diseases, the original purpose of this project was to develop a diagnostic tool for glioblastoma鈥攐ne of the most aggressive and treatment-resistant brain tumors,鈥� Sugaya says. 鈥淥ur method offers a rapid, non-invasive way to detect glioblastoma multiforme (GBM) by analyzing surface markers on exosomes, which reflect tumor-specific antigens.鈥�
Sugaya says this technique is part of an ongoing effort to not only improve diagnosis but also advance new approaches to treatments.
鈥淭his diagnostic platform complements a novel therapeutic strategy we recently developed: an exosome-based drug delivery system that delivers non-nucleic-acid medicines directly to GBM cells,鈥� he says. 鈥淭his approach has shown strong potential as a curative therapy, and the diagnostic system we created will also serve as a valuable tool for monitoring treatment response and disease progression.鈥�
The researchers on the team across the two colleges agree that interdisciplinary collaboration was key to achieving results.
鈥淐ollaboration allowed us to integrate biological insight with technological innovation,鈥� Huo says. 鈥淭he synergy enabled us to optimize both the design and function of the isolation platform.鈥�
Ambrosius says as a student researcher, the collaboration opened valuable doors.
鈥淔rom the perspective of a graduate student, it’s interesting to learn that the research field isn’t always about how much you know, but also who you know,鈥� she says. 鈥淧rogress is nothing short of a team effort.鈥�
About the Researchers
Sugaya has dedicated over 40 years to neuroscience research focused on Alzheimer鈥檚 disease, with an emphasis on stem cells for the last 26 years. He moved to the U.S. after receiving his Ph.D. from the Science University of Tokyo in 1988. He joined 麻豆原创 as a professor in 2004. His cancer research began in 2010 when he discovered stemness gene expressions, the self-renewing and differentiating property that allows cancer stem cells to grow and spread. He has become recognized as an expert in the field of exosome research and recently received Florida Innovation Funding from the State Department of Health for his studies.
Huo鈥檚 current research focuses on the development of new analytical and diagnostic technologies to address the health issues of humans, animals and agriculture. Huo received her bachelor鈥檚 degree in polymer science from the University of Science and Technology of China in 1991, master鈥檚 degree in chemistry from Sun Yatsen University in 1994 and Ph.D. in chemistry from the University of Miami in 1999. Her laboratory has developed a rapid blood test to measure the immune health of humans and animals. She collaborates extensively with biomedical scientists, medical doctors, animal scientists, veterinarians and plant scientists to develop innovative solutions for practical and challenging problems.
