The present invention relates to the field glycosylation engineering of proteins. More particular, the present invention is directed to the glycosylation engineering of proteins to provide proteins with improved therapeutic properties, e.g., antibodies, antibody fragments, or a fusion protein that includes a region equivalent to the Fc region of an immunoglobulin, with enhanced Fc-mediated cellular cytotoxicity.

A self-assembling nanoparticle drug delivery system for the delivery of drugs including peptides, proteins, nucleic acids or synthetic chemical drugs is provided. The self-assembling nanoparticle drug delivery system described herein includes viral capsid proteins, such as Hepatitis B Virus core protein, encapsulating the drug, a lipid bi-layer envelope and targeting or facilitating molecules anchored in the lipid bilayer. A method for construction of the self-assembling nanoparticle drug delivery system is also provided.