This team had previously managed to get a couple of cells to perform basic addition tasks, but for this project, they made bespoke genetic programs for each of the nine individual human cell types involved in their biocomputer.
Disallowing them to respond to a wide array of biochemical signals, as they normally would, each was altered to execute just one, clearly defined computational instruction. This allowed the collective cells – the biocomputer – to perform “full-adder” calculations, which essentially means it can perform more detailed, interrelated sums simultaneously. By rearranging the cells, different types of calculations could be carried out.
There are wires here, in a manner of speaking, but unlike static copper ones, this system can “produce and sense chemical communication wires” to perform computational tasks. It's a remarkable system, one that has the potential to adapt and evolve.
Biocomputation is a nascent research field. It’s incredibly difficult to engineer a system like this, because biological matter is far more intricate and mercurial than copper circuitry. Forget simple addition, though: If efforts like this continue, expect to see implantable, living computers within animals – those perfectly integrable with their own biology – in the near future.
A 2009 paper spoke of a world in which these systems will be used to diagnose diseases and create “designer” cell functions within other lifeforms. Noting that “biocomputers are man-made biological networks whose goal is to probe and control biological hosts – cells and organisms – in which they operate,” it's clear that a brave new world is emerging from over the horizon.