Organs on Ice

Organs generally have to be shipped someplace after the donor no longer needs them and they are kept very cold because cold temperatures slow down the natural process of decay, but ice in the tissues is bad. Living cells are severely disrupted by ice crystals, which is why we can't really freeze people, then thaw them out later and expect them to survive.

So, if you want to keep them cold but not frozen, you want some kind of antifreeze that won't kill or harm the tissues. It turns out that sugars dissolved in water can do that, but the antifreeze capability of a sugar depends on a lot of factors. It depends on the number of water molecules bound to it, the shape and make-up of the sugar, and what kind and how much other sugar is dissolved in the water.

Chemists have come up with a (new and probably better) way to figure all that out. They call it the hydration index and here is a link to an article about it.

Hydration Index: A Better Parameter for Explaining Small Molecule Hydration in Inhibition of Ice Recrystallization

Word of the Day

Steriochemistry: The study of the way atoms are arranged within molecules. It turns out that the arrangement in space of the atoms is very important. The same numbers of atoms of each element can be rearranged in ways that make the molecules act very differently.