Figure 1. Summary of the delivery vectors primarily tested for nucleic acid therapy in HNSCC.

Naked DNA in the form of plasmids or oligonucleotides can freely diffuse across the plasma membrane and may enter the nucleus for expression. Microbubbles carrying nucleic acids ruptured at the tumor site by ultrasound, release nucleic acids cargo that diffuses into tumor cells. Liposomes with or without targeted peptides fuse with the plasma membrane and deliver cargo into the cell. Polymer vehicles diffuse across the plasma membrane and release the payload into the nucleus or cytoplasm. Viral vectors can efficiently deliver exogenous nucleic acids into tumor cells. Oncolytic viruses specifically replicate and lyse target tumor cells.