Gene therapy consists of three basic steps: (i) constructing a genecarrying
vector, (ii) transferring genes into target cancer cells with the
vector, and (iii) expressing gene products to kill cancer cells. Constructing
an effective vector for carrying therapeutic genes is essential for
successful gene therapy. Gene-carrying vectors can be divided into two
categories: non-viral vectors and viral vectors. Non-viral vectors, such
as naked plasmids, microbubbles, nanoparticles, liposomes, and polymers,
are safe, low-cost, and offer large insert size of genes; however,
in vivo gene transfection and expression is inefficient and transient,
despite low immunogenicity