Researchers have synthesised fluorescent nanoparticles that can selectively bind to lysosome, an intracellular organelle, making them potentially useful for detecting defective lysosome and diagnosing lysosome-related diseases1.

Lysosome secretes enzymes and play vital roles in energy metabolism, cell membrane repair and intracellular signaling processes. Defects in the structure and functions of lysosome lead to various diseases, such as cancer, nerve diseases and pigment-related bleeding disorders. Existing semiconducting quantum dots that are used to track functions of lysosome are chemically unstable and toxic.

Scientists, led by Amitava Das and Sumit Kumar Pramanik, from the CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, in Gujarat, produced biocompatible peptide-coated nanoparticles using sodium yttrium fluoride, ytterbium and gadolinium. They then tested these nanoparticles’ efficiency in locating malfunctioning lysosome inside cells.

After incubating the nanoparticles with specific biological cells, these cells were exposed to laser light. Sophisticated imaging techniques showed that the nanoparticles entered the cells and emitted green light.

The nanoparticles were found attached only to lysosome, showing their specific affinity for this organelle.

“Since lysosomes are present in all types of cells, lysosome-tracking nanoparticles can be used anywhere in the body for diagnosis and fluorescence-guided surgery even for brain,” says Pramanik.