MNSWLGM · An optofluidic platform based on liquid-gradient refractive index microlens for the isolation and quantification of extracellular vesicles

Extracellular vesicles (EVs) describe distinct populations of small (30-200 nm) and large (500 nm-2 μm)microvesicles actively or passively secreted by cells. Whilst, they are recognized as promising biomarkers fordiseases diagnosis, prognosis and therapy, their purification, selective enrichment, and characterization remainsimmensely challenging. The goal of the current proposal is to develop an optofluidic platform able tomanipulate and characterize single EVs and facilitate their efficient purification and quantitation frombiological samples. The optofluidic platform will incorporate a dynamically reconfigurable optical lattice(constructed from a liquid gradient refractive index - L-GRIN microlens) for separation followed by a viscoelasticfocusing module for single EV imaging. The strength of the interaction between a nanoparticle and the opticallattice will depend on the optical polarizability of the particle, thus providing a size selection criterion to allowidentification and isolation. Put simply, we aim to develop a size-selective optofluidic platform integrated fornon-invasive EVs sorting and fractionation that can be applied to a wide range of biological matrices andaddresses the most challenging technological bottleneck in EVs research.