An exosomal composition is provided that comprises a therapeutic agent encapsulated by an exosome. The therapeutic agent can be a phytochemical agent, a chemotherapeutic agent, or a Stat3 inhibitor. Pharmaceutical compositions comprising the exosomal compositions are also provided. Methods for treating an inflammatory disease or a cancer are further provided and include administering an effective amount of an exosomal composition to a subject in need thereof to thereby treat the inflammatory disorder or the cancer.
