Researchers at the Japan Advanced Institute of Science and Technology have developed a method to isolate intact lysosomes from cells. The technique is rapid and produces samples of high purity. Lysosomes are the organelles responsible for disposing of waste within a cell and are implicated in numerous diseases, from lysosomal storage diseases to autoimmune diseases, certain cancers and neurodegenerative diseases. However, they are difficult to study because current techniques for isolating lysosomes from cells result in samples of low purity and damaged or altered lysosomes. This new approach uses nanotechnology to rapidly extract a highly pure lysosome sample from cells.
Lysosomes digest large molecules in cells and produce metabolites. When this process goes awry, serious illnesses can result, which researchers are trying to study in detail. However, isolating these tiny organelles is challenging. One approach is to centrifuge samples of lysed cells very quickly, which separates the lysosomes based on their density. However, this is a fairly crude way of isolating lysosomes, and many other organelles are often mixed into the isolate. It’s also pretty slow.
Another technique involves using magnetic beads covered with antibodies that bind to lysosomes, allowing researchers to isolate them with a magnet. This results in a purer isolate, but alters the proteins in the lysosomes, affecting protein analyzes scientists may want to perform. To address these issues, researchers in Japan have developed a new method for isolating lysosomes.
They have created hybrid magnetic-plasmonic nanoparticles containing an iron-cobalt alloy and silver. The particles are also coated with aminodextran, and unlike other magnetic particles used to isolate lysosomes, cells readily endocytose them, meaning they are taken up and eventually end up in an intact lysosome. The technique then involves rupturing the cells and harvesting the intact lysosomes with a magnet.
The particles can also be visualized using plasmon imaging, allowing researchers to track their progression through a cell until they are bound in a lysosome. This imaging meant the researchers could calculate the best time to lyse the cells and harvest the lysosomes because they knew exactly when they were inside the lysosomes. The method is very fast and results in highly pure lysosome samples.
“We found that the maximum time required to isolate lysosomes after cell disruption was 30 minutes, which is significantly shorter than the time required with centrifugation-based techniques, which typically require a minimum separation time of several hours,” said Shinya Maenosono, a researcher involved in the study. “Given the profound relationship of lysosomes to many cellular metabolites, a deeper understanding of lysosomal function is necessary to determine their regulation in different cellular states. Therefore, our technique may contribute to a better understanding and treatment of lysosomal diseases in the future.”
Studying in ACS Nano: Fast and gentle isolation of intact lysosomes with hybrid magnetic-plasmonic nanoparticles
