Grow a New Limb

This remarkable report claims that scientists have built a new limb from the collagen matrix of a rat’s paw. They started with the limb from one rat, and used a detergent to wash away all the cells from the collagen that holds the limb’s shape. Presumably they kept the bone too; I’ve not yet got through the paywall for the details.  Then they added cells from a new rat, and the cells grew out, forming all the requisite muscle and blood vessels. A graft to the new rat behaved as native tissue. It doesn’t sound like the researchers connected nerves yet, but still impressive.

While this feat sounds remarkable, in fact, collagen matrix (a natural mesh of protein) has been used for many years to restore tissue; for example, receded gum tissue. Collagen from a cadaver is stripped of cells (which harbor the MHC genes and proteins of tissue type) then pasted onto the roots of your teeth. New gum cells migrate into it, restoring the gums.

Who knows; maybe a head transplant‘s not so far away. We know a lot of political candidates who could use one. The ultimate answer to climate change denial.  More on climate change this week.