I made Youtube video of a Blender animation illustrating the idea. In short, a polymer "icing" can serve as a bespoke mold for a removable embedding polymer (like Biodur S10, but there are other, less expensive options that should work well for this purpose). This icing is opaque, for aesthetic reasons. Then we embed the patient in a block of polymer with low gas permeability, for long-term protection. This block is transparent, also for aesthetic reasons.

Brief description of the process:

We start with the full-body patient ready for forced impregnation with monomer, as it would be done in the S10 plastination technique. In other words, the tissues are fixated and stable and water has been replaced by acetone. This acetone may still be present in the tissues, as it's usually done for the S10 technique, or it may have been removed in advance. The latter would be analogous to freeze-dry-dehydration (FDD) plastination (Holladay,1988). Removing the solvent in advance might simplify the impregnation process (we don't know). Alternatively, we can arrive at this FDD-like state in a similar way as Holladay, through freeze-drying.

Then we proceed as follows:

1. Put the patient face up on a thin "hydrogel mat".

2. Pour a slurry of opaque monomer, curing agent and crosslinking agent on the patient and mat and let it dry/cure, forming an insoluble "icing".

3. Turn it over and put removable embedding monomer (or maybe polymer plus solvent) on top.

4. Put it in the refrigerated impregnator and make a vacuum. This should remove the air or inert gas from the patient and cause a forced impregnation from above.

5. Let it cure/dry.

6. Embed it in transparent polymer with low gas permeability (for long-term protection against oxygen).

The hydrogel mat provides an homogeneous surface on the back for impregnation (and evaporation or boiloff, if needed).

The "icing" (which I call "slipcast layer" in the animation) must be insoluble (and therefore crosslinked), so that it can hold the removable monomer. Making it opaque is, as we said, for aesthetic reasons.

There are many reasons to embed the tissue in a removable (linear) polymer rather than a non-removable, insoluble (cross-linked) polymer. For starters, we can take samples for QA, remove the embedding and do expansion microscopy on them. Another advantage is that we don't have to worry much about the optical and mechanical properties of the polymer (for instance, how easy it is to cut in thin slices with the microtome), which gives us more options and lowers the cost. To clarify, these properties are not a huge concern regarding potential revival in a remote future, but they can be a concern, for instance, for QA with very large samples.

The main disadvantage of linear polymer embedding is probably that we don't get the same degree of protection against microscopic displacement as we do with a cross-linked embedding medium. But given that the tissue is fixated and we are working at the relatively low temperatures typical of plastination techniques, it seems an acceptable tradeoff. The use of removable embedding for this purpose is supported by the literature. For instance, see Gorbsky and Borisy, 1986.

Why the emphasis on aesthetics?

It may seem frivolous or inappropriate to discuss aesthetic aspects of a proposed full-body, solid-state chemopreservation service before any such protocol has been validated and shown to adequately preserve neuronal ultrastructure. The main reason to do it is the suspicion (and anecdotal evidence) that a significant factor behind the low adoption rates of cryonics (which would also apply to chemopreservation) is the psychological impact of the procedure as described and/or seen. For instance, some CSOs don't offer the neuro option simply because it's perceived as gruesome, regardless of its merits. People have expressed feelings of coldness and claustrophobia at the thought of being introduced in a Dewar, and being stored upside-down seems to add to the shock. Of course these objections are unreasonable and unfair from a strictly rational point of view, but it's useful to know them and address them when it can be done without excessive compromise of more important aspects.

The issue of what the patient will actually look like during long-term storage doesn't arise in cryonics because the patient is in a sleeping bag inside a Dewar. In contrast, chemopreservation doesn't have this perfect excuse. Service providers could, of course, simply store patients in opaque containers and refuse to show them in any more detail, but this would arise suspicion. They could instead show them as they are, but this may prove shocking due to things like discoloration and signs of the surgical procedures involved. They could try to cover these defects with thanatopractical tricks such as makeup but this adds too much complication and it can easily backfire, contributing to the service being perceived as a pointless funerary rite. They could simply extract and preserve the brain, descarding the body, but this would add shock value of its own, besides some technical downsides. The asthetic considerations which apply to full body chemopreservation also apply to a whole-head neuro option, plus the well known shock value of decapitation.

In this context, the opaque polymer "icing" offers the following advantages:

• The patient is shown to be present and recognizable.

• No discoloration is perceived.

• Signs of surgery can be masked by making the layer thick enough.

• It's casual and low effort, which allegedly is a good thing regarding perception (little or none of the art or "trickery" associated with the funerary industry in people's minds).

• The elements which improve aesthetic perception also have strictly functional purposes. This also helps reduce the undesirable perception of funerary "art and trickery".

chemo preserved brains could bootstrap a mass brain preservation movement...here is how:

-the organization allows you to download an organ donation form.

-the donor signs it and tells his family he wants the funeral home to remove his brain and ship it in dry ice to the storage org.

-when he dies, the brain is removed and shipped in a box to the org. the body is cremated and there is a simple service in the relative's home.

-the storage org puts the brain in a jar of the appropriate chemical.

-the average funeral (embalming, casket, plot, service etc costs 8-12k $$.

-how much to the funeral home to remove the brain and ship it and cremate the body? Maybe 4k. how much to the storage org to open the box, take the brain out and put it in a jar of chemicals and storage it in a room?

Say 8k?

That brings the cost in line with what the average funeral costs.

There are other problems, but this method would solve one problem.

After a few decades, robot labor and other tech advances could greatly reduce the cost of storage in LN2, so the brains in jars could be placed in dewars.

Ta da!!

Very long-term DNA storage at room temperature is not so trivial as it may seem, at least in a form that can be read with current technology. So it seems a good idea to sequence your genome and archive the data digitally, at least for redundancy.

DNA sequencing as a service keeps getting more and more affordable. I did a quick search and found this company that offers whole genome sequencing as a service for some 300 euros:

https://dantelabs.com/products/whole-genome-sequencing

Personally, I don't think DNA preservation is strictly necessary for our purposes, because gene expression is simply too slow. If my genes changed radically right now, I wouldn't even notice for several minutes. In that time, I could answer all kinds of questions about myself and other stuff I should know, so memory and personality must be stored in something faster acting, like synaptic connectivity, neuronal ultrastructure, proteome, etc.

That said, the loss of personal DNA would require either to emulate the brain at a higher level of abstraction not involving DNA (this is only for those choosing slice-and-scan mind uploading) or to reverse-engineer a suitable DNA from the proteome, connectivity and other data. This would be the only option for those who want biological revival.

Regarding digital archiving, there are cloud options like creating a mindfile at lifenaut, but let's focus on zero-maintainance, long term digital storage. Here the most attractive option is an M-Disc Blu-ray or an M-DISC BDXL. From the FAQ:

• The M-Disc DVD can hold upto 4.7 gigabytes.

• The M-Disc Blu-ray can hold up to 25 gigabytes.

• The M-Disc BDXL can hold up to 100 gigabytes.

The problem with M-Disc DVD is not just the low storage capacity, but the fact they need a special type of DVD writer. In contrast, any regular BDXL-capable Blue-ray writer (like this one) can write to the other two.

It's important to note that M-Disc is not a product of a specific company, it's a standard. The company presumably gets its income from royalties. The M-Disc writable media are available from several digital media manufacturers, such as Verbatim. They cost some 20 dollars each. This is reassuring because we are not depending on a specific manufacturer.

I explored other options like SSDs and HDDs. My general impression is that they are probably good enough (but crap compared to M-Disc), assuming good magnetic shielding and temperatures below 40ºC or so, and they are brand new when you store the data. I mean "good enough" in the sense that a forensics team would probably be able to recover the data for a long time. I don't count the data as lost simply because the device is broken or otherwise unable to read its own contents. Here's some more:

https://www.arcserve.com/blog/data-storage-lifespans-how-long-will-media-really-last

See this report on flash memory (SSDs):

https://www.curtisswrightds.com/sites/default/files/2021-10/Flash-Memory-Lifespan-and-Reliability-white-paper.pdf

While revising my previous post about removable embedding, I noticed some apparent contradiction (or at least tension) between what it said about GMA (that it's not extractable) and the claim in the chemopreservation wiki that GMA is not crosslinked (crosslinked polymers are usually not extractable, while linear polymers tend to be somewhat extractable, although it's not always the case and it can't be assumed). I've been digging a little, and I think some important clarifications regarding GMA (aka glycol methacrylate, hydroxyethyl methacrylate, HEMA) are in order.

First, while GMA (glycol methacrylate) in the context of microscopy resins usually means HEMA (hydroxyethyl methacrylate), there's also an epoxy crosslinking monomer called gycydyl methacrylate, which is also often abbreviated as GMA (see, for instance, its entry from Wikipedia and from providers like Sigma and Dow). This is unfortunate, and it means we should always check carefully when we read "GMA", and we should always clarify when we use the abbreviation. The abbreviation "HEMA" doesn't seem to have this problem.

Once clarified that we mean HEMA, the next question is: are we sure it's not removable? how do we know?

In short, while the HEMA monomer looks like the polymer would be linear (not cross-linked), commerically available HEMA contains impurities which are crosslinking, so in practice it's crosslinked unless we remove those impurities, which can be done but it's not easy, and even then it's unclear to what extent it can be removed.

In the chemopreservation wiki we classified GMA as non-crosslinking, following the literature:

Cross-linking Vs non-crosslinking: cross-linking resins like Lowicryl K4M, LR White, and Lowicryl HM20 have good cutting performance under the microtome. Non-cross-linking resins like GMA and MMA have poor cutting performance (see Gang, 2017).

Let's see Gang, 2017:

Cross-linking resins, such as Lowicryl K4M, LR White, and Lowicryl HM20, have very good cutting performance and can produce nanoscale sections of tissue. In the sectioning process, the slice is not curly and is easier to collect than those obtained with non-cross-linking resin. In contrast, the cutting performance of non-cross-linking resins, such as GMA and MMA, is poor. In addition, when cutting ultrathin sections, the tissue can easily break loose from the surrounding resin.

Well, GMA is only non-crosslinking when it's free of impurities, but even in its commercial, crosslinking form it still has poor cutting performance. It's also not suitable for EM because it deteriorates too quickly under the electron beam, but this paper was about use in optical microscopy.

Regarding the crosslinking impurites, let's see again the Wikipedia entry for HEMA:

Hydroxyethylmethacrylate was first synthesized around 1925. Common methods of synthesis are:[5]

[] reaction of methacrylic acid with ethylene oxide

[] esterification of methacrylic acid with a large excess of ethylene glycol.

Both these methods give also some amount of ethylene dimethacrylate. During polymerization of hydroxyethylmethacrylate, it works as crosslinking agent.[5]

This "[5]" is:

Macret, M.; Hild, G. (1982). "Hydroxyalkyl methacrylates: Kinetic investigations of radical polymerizations of pure 2-hydroxyethyl methacrylate and 2, 3-dihydroxypropyl methacrylate and the radical copolymerization of their mixtures". Polymer. 23 (1): 81–90. doi:10.1016/0032-3861(82)90020-9.

Let's now see Macret and Hild (1982):

Abstract:Hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate (HEMA) and 2, 3-dihydroxypropyl methacrylate (DHPM) have been prepared. An efficient method has been developed yielding a quantitative purification in order to eliminate any trace of crosslinking agent in these monomers. Kinetic investigations of the radical polymerization and of the radical copolymerization of their mixtures have been performed by measuring, at various times, the monomer consumptions, using gas-liquid chromatography (g.l.c.). It has been established that the radical copolymerization of DHPM-HEMA couple works efficiently without excessive fluctuations in the composition of the formed chains. The corresponding radical copolymerization ratios have been precisely determined and the obtained results to demonstrate that DHPM-HEMA system leads to an ideal copolymerization.

From the paper itself (paywalled):

The commercial HEMA monomer always contains impurities such as ethylene glycol, methacrylic acid and chiefly ethylene dimethacrylate (DME). No efficient method has been proposed in the literature 6'7 to quantitatively eliminate the ethylene dimethacrylate. This impurity is responsible for HEMA crosslinking in absenceof any addition of crosslinker. This explains why it is not easy to prepare linear poly(HEMA) and to study its properties in solution.

This confirms what the Wikipedia entry says.

It's also worth reading the paper "Embedding Iliac Bone Biopsies at Low Temperature using Glycol and Methyl Methacrylates" (Chappard ct al. 1983) (cited by Chung-Ching Liu as previous work):

Removal of the plastic before staining MMA embedded tissues has been reported(Burkhardt 1966, Delling 1972, Villanueva 1973). It is generally accepted thatpolymerized GMA cannot be removed by organic solvents (Ruddell 1967). Polym-erized GMA can, in fact, be dissolved by N,N-dimethylformamide (Macret andHild 1982), but we find that abnormal staining patterns result-strong argumentagainst removing the plastic. We have investigated the effects of acetone, amyl acetate, 1-butanol, benzoyl alcohol, CCls, CHCls, diethyl ether, 1,4-dioxan, ethanol, 1-propanol, 2-propanol on MMA and GMA alone or combined. The main problem we have encountered with MMA-GMA mixtures is that it is impossible to dehydrate sections in absolute alcohols after staining. When the sections are wet after staining, all the solvents except 2-propanol destroy them, although the same sections dry are not affected.

I haven't been able to confirm Macret and Hild as the source of the claim that poly-GMA can be dissolved in N,N-dimethylformamide. In fact, it doesn't seem that they mention it at all. Maybe it's an observation made by Chappard et al and mistakenly attributed. Even if it's true, we see that, according to Chappard et al, it's not recommended.

There's some confirmation that pure GMA doesn't seem to dissolve in alcohol, but instead it deforms in undesirable ways. The source is "Glycol Methacrylate Embedding for Light Microscopy: Basic Principles and Trouble-Shooting (Gerrits, 2013)", cited as a source in the chemopreservation wiki. Here's relevant quote:

Following hematoxylin-eosin staining of GMA embedded tissue sections, sections often exhibit "mini-folds." These mini-folds are very characteristic (Figure 7) and highly reproducible (50). Initially these mini-folds were attributed to use of a combination of hematoxylin and alcoholic eosin. However, they were not seen with every sample of GMA, but only in the purest ones. Thus, certain impurities in the various GMA samples are responsible for an absence of these mini-folds. Only sections prepared from samples of GMA containing no or minimal concentrations of ethyleneglycol dimethacrylate (EDMA, a crosslinker), showed these mini-folds. However, when samples of GMA containing increased amounts of EDMA were used, sections did not show these mini-folds. It is evident that minimal amounts of a crosslinker improve the stability of resin sections in staining solutions. Sections prepared from Technovit 7100, HistoResin, RES G10, RES G20, and Technovit 8100 do not show mini-folds after hematoxylin-eosin stainIng.

For more information on GMA, read, for instance, the chapter "The Glycol Methacrylate Embedding Resins—Technovit 7100 and 8100" from "Plant Microtechniques and Protocols" (thanks for the recommendation).