The present invention relates to the field of extracellular vesicles. More specifically, the present invention provides methods and compositions for using extracellular vesicles as a vector for nucleic acid treatment in vivo of various diseases. In a specific embodiment, the present invention provides an extracellular vesicle isolated from a cell comprising one or more microRNAs (miRNAs) that have been loaded ex vivo into the vesicle so that the miRNAs are present in a higher concentration than when measured in the same extracellular vesicle isolated directly from the cell. In another embodiment, the present invention provides a method for treating cholangiocarcinoma in a subject comprising the step of administering to the subject a plurality of exosomes comprising miR-195.