As I have written extensively MMP enzymes are the LIMITING factor in connective tissue degeneration. The long list of modifiers alond with connective tissue amplifiers should help to slow, stopp, or reverse damage.
There are MANY types of stem cell based operations for Discs.
What the "legit" medical community is working on is harvesting MSC stem cells for bone or fat, multiplying them out of the body is some cases, THEN adding in growth factors to change them into the proper tissue while OUTSIDE the body. In this case it would be some kind of articular,disc tissue, then this tissue can be applied to a graft material and placed withing the disc, or injected into the disc space. This is specific placement of specifically differentiated MSC's.
I had the "experimental" fat based stem cell done for muscles and tendons from Cipro toxicity. In this case they take out your fat, harvest MSC's, combine them with your own PRP that contains growth factors for cartilage, bone, muscles, etc. They use a laser to cause a certain percentage to differentiate, than they inject the WHOLE mix into wherever you need it.
This could be called "non-specific differentiated MSC's" placed into
1. Specific tissue such as discs, tendons, muscles, brain (through nose)
2. NON-specific IV administration.
I had IM, intranasal, and IV done.
Intra-nasal carries a VERY SMALL risk of blindness through the blocking of the eyes' arteries as can happen with many facial injections.
What isn't know yet is if fat based MSC's injected into discs will incorporate into the damaged tissue.
What also isn't know yet is if the Liver will filter out most of the MSC's aftr X amount of time.
All this aside, I would try micro-current therapy, bromealin, all the MMP modifiers, and LED light therapy and I would stay THE HELL AWAY from prolotherapy.
If I did get Stem cell disc injections I would defineltyh use LED light therapy.