It's been a while since I looked at this stuff so apologies for the rustiness

Columbia trial paper: https://www.nejm.org/doi/full/10.1056/nejm200103083441002

Tampa trial paper: https://pubmed.ncbi.nlm.nih.gov/12953276/

Additionally, it looks like I totally missed at least one European program at Lund University (review paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5345652/)

I've heard rumblings re preclinical prep work w/ the Takashi group at Kyoto University as well, not sure where that's at at the moment.

I randomly found this review, but haven't had a chance to plough thru it yet, but I wouldn't be surprised that the stem cell tech these days makes whatever they used 20 years ago ancient and crude by comparison https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9890289/

Additionally, this was the followup paper that found Lewy bodies developing in the transplanted cells (suggesting some sort of spread/prion-like hypothesis with regards to Lewy bodies/insoluble alpha synuclein)

https://pubmed.ncbi.nlm.nih.gov/18391962/

edit: competing group also managed to publish theirs at the same time

https://pubmed.ncbi.nlm.nih.gov/18391963/