Plastination seems to have the potential to become a viable alternative to cryonics as a long-term storage method for the brains of those who die before the advent of rejuvenation biotechnology. If the fine structure that encodes the data of the mind is preserved, then these individuals can wait indefinitely for the arrival of molecular nanotechnology needed to restore them to life. Cryonics has been around for decades, and has had its challenges, while plastination remains a comparatively new idea - and thus we should expect there to be hurdles to overcome.
One of my concerns with room temperature storage of plastinated individuals is the potential for bacteria and bugs than might like to consume the fixative compounds, something that isn't a concern in low-temperature storage. Here is another:
I have always been interested in chemical fixation as a (low cost) alternative for cryonics. In fact, years before all the talk about the "connectome" and "plastination" I spent considerable time exchanging messages with Michael Perry at Alcor about the technical and practical feasibility of chemical brain preservation. But no matter how open minded I tried to be about this approach, I kept running into the same challenges over and over again.
The challenge that has concerned me the most is whether a delayed start of chemical brain fixation will produce incomplete distribution of the chemical fixative in the brain because of ischemia-induced perfusion impairment. Thinking about the technical problem of "no-reflow" is not the first thing on the mind of someone who first hears about the idea of using chemical fixatives to preserve the brain. In my case, this concern was not just "theoretical." In my lab I have spent many years looking at the effects of cerebral ischemia on cryopreservation and chemical fixation. Last year we decided to broaden our investigations to delayed chemical fixation and we have not been pleased at what we have observed so far. After 1.5 years of room temperature storage the delayed aldehyde fixed brains are falling apart and continue to decompose. In small animals one might imagine that such perfusion impairment could be overcome by immersing the brains in the fixative instead but human brains are simply too large. By the time that the fixative would have reached the core of the brain, extensive autolysis will have occurred.