Under this
$1 you will get explained how currently is the state of stem cells replacement, why it's so complicated, why it's going so slow, why implanting directly into eye or bloodstream is risky or useless, why not go to China. It's from 2020.
I am from Germany, there were many stem cell "clinics" offering "treatments" for everything you wanted if you paid private hundreds of thousands of Euros. I was really interested because of other degenerative eye disease and regenerating my damaged fully blind eye to regenerate my optic nerve. We also had contacts with Japan and USA.
Many clinics were shut down not only in Germany but in Italy, Czech, France etc because the clinics were not treating properly. As for now it's all in clinical trials because of safety reasons, the cells after infusion aren't controlled into what they will change it's Russian roulette: undeveloped cells, mutated cells, cancer cells... Any kind of cells that are in body - yes i don't mean embryo cells because those are banned in Europe but cells created from your body. All of this is as clinical experiment on humans.
It's against the European medical law to pay for clinical studies as patient mountain of money for such thing, receive no long term care afterwards, no follow up for side effects, no extra insurance, no release if research papers results and statistics. All was closed no third party was allowed to check even patients doctors who later taken care of them in home country. Clinics in China are doing the same, as for now it's dangerous practice for 15 years they close one clinic new one with new name pop up elsewhere.
Singing up contract for treatment you agree to use all your data, your story for marketing: one man died disease speeded up while on stem cell treatment but clinic but his photo and story as "successful cured happy patient" for years. Family went to court but they had hard time winning this because of some tricky points in clinics policy.