I dont understand the biology behind biontechs spleen targeting secret sauce (i dont think they did either, but it got them a patent on an otherwise standard lipid formulation). there is a really good nature paper from summer 2016 that outlines a lot of their preclinical dev; the CEO said he sort of regrets publishing that as a lot of competitors sprang up afterwards

out of curiousity, what's the exosome hype? ive heard a few strong life sci VCs mention it, but i talked to a ceo of an exosome company and didnt quite understand the specific therapeutic potential