Ann: Quarterly Activities Report and Appendix 4C, page-34

Will a HEK293 cell line - that's human embryonic kidney if I recall correctly produce the same exosomes as say are of interest in mesenchymal stromal cell therapies?

Whilst I think its sound to have some in-house development capability and GMP (Cynata in my opinion suffers for the lack of that - you pay through the nose for even minor developments) if Ex1 wants to modify natural exosomes by adding tags to the lipid skeleton for directing to particular sites and by loading particular gene products into the exosomes then it seems they also need to know quite a bit about the natural proteins on the surface of their exosome producing cell lines.

Right now I don't know if the natural exosomes coming out of HEK293 lines are well characterised enough that anyone could say confidently that there isn't something on the surface of the exosomes that might be still be unknown in its operation jet having an effect on where the exosome attaches.

Its not clear to me that a single cell line will be enough to produce exosomes that are sufficiently like the exosomes that other cell lines would naturally produce. We (team humanity in the scientific enterprise) might need multiple cell lines to get multiple varieties of exosomes at least until such time as the natural surface molecules of exosomes from certain cell types are better characterised.

The above will be confusing probably - what I am saying in another ways is that because exosome knowledge is still pretty knew its possible I think to be confident that with cell engineering we (team humanity in the scientific enterprise) can add new surface molecules to the exosome if we want to. And can add new contents to the exosomes if we want to. But until we know all that is involved in doing anything on the surface of an exosome from a paricular cell we don't know enough to know what we have to change to make an exosome from an HEK293 seem like its an exosome from say a Mesenchymal stem cell.