Generation of Nanovesicles using Microblades for Exogenous Materials Delivery

Abstract

We propose a system that can make nanovesicles for exogenous material delivery using sharp microblades. We use conventional MEMS technology to fabricate micochannels with low-stress SixNy cantilever-blades on a chip. Living murine embryonic stem (ES) cells are sliced by the blades while being extruded through the microchannels. Plasma membrane fragments sliced from the cells self-assemble into spherical nanovesicles 100-300 nm in diameter, due to amphiphilic property of lipid in aqueous solution, analyzed by the minimization of free energy of lipid bilayer. The main cause of the nanovesicle generation in the system is the existence of blades, because a flat surface and natural vesicle secretion have little effect on nanovesicle generation. The nanovesicle generation efficiency of the chip was confirmed by comparing the amount of total amount of cellular contents in nanovesicles and in the same number of cells used in nanovesicle generation. The system produce ~100 times more nanovesicles than the number of exosomes produced by the same number of ES cells. The nanovesicles contain endogenous cellular contents from the ES cells, including membrane proteins, cytosolic proteins, and RNAs. The nanovesicles also can encapsulate exogenous materials (polystyren bead/pDNA) and deliver them to recipient cells. The encapsulation efficiency was confirmed using fluorescence intensity. This system can be used in exosome-related research and may have applications as vehicles for delivery of exogenous contents.