Here are some links on patents:
nano particle / nasal drug delivery through the blood brain barrier
http://www.dl.begellhouse.com/journals/3667c4ae6e8fd136,591e9c894319db7c,0112f1970a0a1ae6.html
more nano nasal drug delivery methods
https://link.springer.com/article/10.1007/s12272-016-0782-0
mrna vaccine delivery using lipid nanoparticles
https://pubmed.ncbi.nlm.nih.gov/27075952/
charles lieber patents are the key
https://patents.justia.com/inventor/charles-m-lieber
quantom dot nano crystals
https://www.youtube.com/watch?v=G-ZYEqa5zSs