ABSTRACT
The key of gene therapy is to deliver the functional gene to the target tissue in the body. The safe and efficient gene carrier is particularly important in the targeted delivery. Multifunctional envelope-type nano device (MEND), based on concept "Programmed packaging", is a new type of gene carrier system, with high encapsulation efficiency, favourable stability, high transfection efficiency, easy preparation, etc. MEND is designed to control intracellular trafficking as well as the tissue distribution of encapsulated compounds such as nucleic acids/proteins/peptides, permitting them to function at the appropriate location. In this paper, research progresses in MEND are reviewed in accordance with three types of payloads:the small interfering RNA (siRNA), DNA and proteins/peptides in recent years.