Gene Delivery Using Physical Methods - Challenges in Delivery of Therapeutic Genomics and Proteomics - page 108

electric pulse [270] . Thus, this study confirms that �BGT is the best alternative to the
gene delivery by EP, as �BTS is a less harmful and less invasive method.
3.11 Impalefection
Genes are delivered to target cells using the simple, fast [275] , and novel physical
method of impalefection, which involves binding the desired gene, plasmid, proteins,
antibodies, and so on, to the surface of vertically aligned carbon or silicon nanotubes,
nanofibers, and nanowires [276] . Gene binding has been performed either by surface
adsorption or by covalent attachment via reaction between gene and binding site on
nanofibers [277] . The nanoconstructs carrying the gene are fixed on a chip, forcing
these nanoconstructs across the target organ for release of the surface-bound gene
directly into the cell nucleus, for efficient transfection [278] . This method offers the
merits of bypassing extracellular and cytosolic degradation of biological molecules
like DNA [278] and high parallel delivery of the gene directly inside the target cell;
it also minimizes the chances of incorporating any foreign gene inside the target
cell [279] . However, the method suffers from the disadvantage of a lack of clinical
applicability.
The impalefection method works on the following principle: arrays of vertically
aligned carbon nanofibers (VACNF) are developed on a flat substrate, and the sur-
face is then coated with the desired gene. When these nanotubes are pressed into the
target organ, using a chip, the tips pierce cell membranes with ease and deliver the
therapeutic gene into many cells at the same time [275] . The impalefection technique
is illustrated in Figure 3.6 .
Figure 3.6 Principle of impalefection technique showing (A) nanotube, (B) nanofiber,
(C) and VACNF, (D) which, after interacting with DNA, get surface coated (E) and are further
carried by a chip carrying an array of VACNF, (F) for bombardment in target cells by applying
physical force on the chip, (G) to result in a transfected cell with successful therapeutic DNA
expression.