Tumor-associated macrophages secrete extracellular vesicles (EVs) that range from a variety of sizes and subcellular origins–.
Exosomes (30-150nm) are a type of EVs originated from endosomal multivesicular bodies, . Other types of EVs result from the shedding of plasma membrane, which leads to the formation of microvesicles (100-1000nm) during steady-state conditions or to apoptotic bodies (100-5000nm) during cell death, .
Tumor-derived EVs are known to play a role in a number of tumor progression processes, such as metastasis and chemotherapy resistance–.
Cianciaruso et al. developed a method to analyze tumor-associated macrophages’ secreted EVs.
Following the proposed method, tumor-derived EVs were isolated from breast cancer cells. They were then harvested and labelled with a fluorescent lipid.
After that, the tumor-derived EVs were added to a mouse macrophage culture and their uptake was monitored for 6 hours under Nanolive’s 3D Cell Explorer-fluo. While data regarding refractive index was obtained every 10 seconds, the cadence of fluorescence acquisitions was increased in order to avoid fluorescence-induced cell perturbations that may had compromised the observed phenomenon.
As observed in the footage, fluorescence intensity increases over time as EVs uptake increases.
Strikingly, EVs structures are visible using Nanolive’s imaging. They appear as small, dotty, membrane-dense structures appearing and growing at the center of the badly resolved fluorescent signal. Thanks to the high temporal resolution, fine dynamics of such process can be extracted.
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