Information systems like social media and video platforms would need to deliberately deprioritize distressing content. The issue with this is that distressing content is more engaging due to neural weighting regarding potential threats (i.e. scary stuff), so the platforms that volunteer to do this will be outcompeted by those that don't.

Through that lens, regulation will be necessary to force an even playing field for all platforms competing in the space.

That portrayal is somewhat accurate for in vivo regeneration. What basically happens is that some of the processes during embryogenesis would be retriggered, resulting in a regenerative event. Though there would be a fairly large difference in what it would look like.

In embryogenesis, the bioelectric patterns dictating morphological goals like "the left side of the head goes here" and "build cardiac nerves here" gradually shift as the organism develops. The goal isn't to build an adult from the get go, the goal is to build the next stage on the way to eventual adulthood. This results in a relatively complete body that becomes more complex and larger over time. This is also why morphological goals are stored in volatile bioelectric networks instead of stable formats like DNA. They need to be modified at will both by developmental events and by other cells that need to coordinate with their neighbors.

With artificially induced morphogenesis, particularly in an adult, the bioelectric patterns would be for a complete adult anatomical structure at the very start; no gradual development here. In the case of an arm, for instance, this would result in growth coming from the stump that would begin forming the adult fingers of the hand very early on. It would look somewhat like a tree as all the parts of the limb would generate concurrently towards the adult shape instead of interim shapes like those of a child or adolescent.

If we can revive the head and somehow provide it with life support, we can theoretically induce morphogenesis at the base of the neck to grow the rest of the body. I'm not sure if you could do it in one pass (i.e. build a body) or if you'd need to induce morphogenesis for each individual anatomical structure (torso, shoulder, heart, left lung, right lung, etc.).

Either way, the process would be insanely creepy because you'd essentially have a baby's body growing out of an old person's head. But it should be doable.

Einstein though isn't coming back. His bioelectric networks, genome, and all other biological information states are beyond recovery. If we had done a full genome sequencing on him and performed a full bioelectric pattern scan somehow, we could potentially have reverse-engineered him. The bioelectric piece would be necessary to create Einstein as he was in adulthood, versus as he was as a freshly fertilized oocyte which is all a genomic snapshot would grant you.

Better than 3D printing, we've actually been growing functioning organs in vivo in the lab for a while. Here's a paper from 2012 where organogenesis of ectopic eyes was induced in the guts of tadpoles via bioelectric pattern modulation: https://pubmed.ncbi.nlm.nih.gov/22159581/

Other experiments have also induced the growth of extra limbs, hearts, brains, etc. in developing frogs using the same bioelectric pathways.

That research developed to the point of regenerating entire limbs in adult frogs that lack regenerative capabilities, in 2022: https://www.science.org/doi/10.1126/sciadv.abj2164

Current research is underway on mice, primarily in limb regeneration.

This is the startup that spun out from that research, if you'd like to keep tabs on them.

https://www.morphoceuticals.com

If you check the link, limb regeneration was achieved in frogs (that don't naturally regenerate) over a year ago. There're other experiments that have produced ectopic organs in tadpoles like extra eyes, hearts, and brains, though it's not as hard to accomplish in an organism that's already undergoing morphogenesis. Limbs are a good research target for morphogenesis in non-regenerative adults because they're isolated anatomically, are external, and feature a wide range of tissues including nerves.

There are studies underway on mice though growing limbs takes a while so it will take another year or three before we see the results of that.

However, the neat thing about this approach is how lateral it is with other anatomical structures. Because it's a top down approach that offloads the work to your cells, the same mechanisms for growing a limb can be used to grow an eye, liver, cartilage, or whatever. Again, this has been proven in tadpoles already. Once limbs are figured out other anatomical structures, like teeth, will quickly follow.

That all said, full in vivo regeneration is probably still another decade or two out from being available as an outpatient service. You'll probably have synthetic teeth produced via 3D printing, stem cell production, or cellular scaffolding before you're regrowing your teeth yourself.

Current understanding in regenerative medicine is that regeneration of that level will probably end up leveraging cellular bioelectric networks instead of DNA. DNA is responsible for dictating the hardware of your anatomy (e.g. proteins) and bioelectric networks are responsible for dictating morphological goals (i.e. grow a finger of this shape starting here). One way of triggering regeneration of teeth will involve modifying bioelectric circuits in your jaw tissues to instruct the cells there to build the tooth that was built previously.

The handy thing about this is that once the circuit is modified, your cells automatically do the rest of the work according to the anatomical mapping contained in the circuit. Including stopping once the structure (tooth) matches the stored mapping.

https://www.science.org/doi/10.1126/sciadv.abj2164

Edit: To directly answer your questions in the context of a theoretical bioelectric repatterning therapeutic:

• Identifying the exact pattern that results in adult tooth formation and the drug combination that can induce said pattern. It's worth noting that there are multiple types of teeth (canine, molar, etc.) that each have a unique bioelectric pattern.
• Potentially local scarring and other biological processes that obstruct regeneration.
• By specifying the pattern for the desired tooth.
• The tooth would regenerate along a similar timeline as the initial formation of the tooth. Months, if not years. There may be a way to accelerate this process, but it hasn't been identified yet to my knowledge.
• Once initiated, it would continue independently. You would likely have regeneration checkups to verify that the growth is proceeding as expected to rule out perturbations in the bioelectric patterns that would result in deformities.
• The procedure wouldn't stop without deliberate intervention, whether surgery to extract the regenerating tissues or modifying the pattern to change the morphological goal from building a tooth to being standard jaw tissue. In the latter case, while it's possible that the cells would automatically revert, I'm only aware of tissues reorienting or "moving" to the target location following perturbation in the case of embryogenesis.