(Andrewk65 wrote:)You suggest that eet technology optimises...

(Andrewk65 wrote:)You suggest that eet technology optimises delivery of payload to a cell. I was under the impression that eet was purely to confirm that the payload entered the cell and escaped the endosome, it doesnt actually enhance the ability to do so.

Consider the following patent ...

WO/2012/159164 - METHOD OF DETERMINING, IDENTIFYING OR ISOLATING CELL-PENETRATING PEPTIDES

"... the present invention provides a method of determining or identifying a cell-penetrating peptide (CPP) capable of being released from an endosome or endosome-lysosome of a cell ..."

So, the patented screening process allows for the identification, through a screening process, of CPPs capable of "being released from an endosome or endosome-lysosome of a cell".

So, in addition to cell type specificity ... the compounds are screened for endosome/lysosome escape.

Note, that if the compound cannot escape - it ends up being "digested" by the cell.

Apologies for the complex language - tried to make it as readable as possible.