# Super-resolution microscopy reveals glioma cell footprints and exosome deposits

## TL;DR

Using advanced microscopy, researchers visualize exosome deposits and cellular footprints in glioma cells, revealing new insights into brain tumor communication.

## Contribution

The study introduces a novel method combining STED microscopy and immunostaining to characterize exosomes at the single-vesicle level in glioma cells.

## Key findings

- CD63-positive exosomes were identified in the extracellular space with sizes ranging from 36.55 to 157.06 nm.
- CD63/actin co-staining revealed different actin polymerization states associated with exosomes.
- Mathematical deconvolution enhanced STED image resolution for detailed exosome analysis.

## Abstract

Gliomas are aggressive brain tumors whose infiltrative growth is mediated by intercellular crosstalk. Exosomes, small extracellular vesicles, play a key role in cell–cell communication but are difficult to visualize using conventional microscopy. Performing immunostaining for CD63, a known exosome marker, and using STED microscopy, we demonstrate exosome secretion in primary glioma cells. Applying mathematical deconvolution, we enhance the contrast and resolution for in-depth analysis of STED images. We identify CD63-positive cellular footprints and exosome deposits in the extracellular space. Quantitative analysis shows CD63-positive exosomes ranging 36.55-157.06 nm in size. CD63/actin co-staining demonstrates different actin polymerization states associated with exosomes. In conclusion, STED microscopy coupled with immunostaining allows exosome primary characterization at the single-vesicle level in the cellular spatial context.