Has anyone done research on loading microRNA into exosomes? Electroporation is too expensive. Are there other methods? Can you advise on feasibility and loading efficiency?

For loading microRNA into exosomes, consider incubation, sonication, extrusion, freeze-thaw, or chemical transfection methods. These methods can allow drugs to enter the interior of exosomes easily. After drug diffusion, the exosome membrane reseals.

The incubation method is relatively simple, does not disrupt exosome membrane integrity, and is suitable for loading hydrophobic small molecules. Electroporation is mainly suitable for loading hydrophilic molecules with high efficiency but may compromise exosome membrane stability. If considering cost and loading efficiency, the incubation method can be chosen.

Besides these, the following methods can also be used to load microRNA:

1.Sonication: During sonication, using an ultrasonic homogenizer probe causes membrane deformation, allowing drug diffusion into exosomes.

2.Extrusion: The exosome-drug mixture is passed through a membrane with pores of 100-400 nm using a lipid extruder to transfer the drug into the exosomes.

3.Freeze-thaw: The exosome-drug mixture is frozen repeatedly (at -80°C or in liquid nitrogen) for several cycles and then thawed to room temperature to ensure successful drug incorporation.

4.Chemical transfection: Exosomes and drugs are incubated with surfactants, causing pore formation in the membrane, allowing drug permeation. The most commonly used surfactant is saponin, hence this method is also called saponin-assisted loading.