The same nanotech approaches being explored to deliver drugs exactly to the cells where they are needed also provide a technology base that might lead to permanent enhancements of human metabolism. Excerpts from “Cell ‘organs’ get plastic upgrades“, by Tamsin Osborne at NewScientist.com news service:
Human cells could have their metabolisms upgraded without altering their genes by inserting tiny plastic packages of enzymes, Swiss researchers have shown. They hope the technique could allow advanced cancer therapies, or even upgrade a person’s metabolism.
The cells of multi-cellular organisms and some advanced single-celled organisms have internal compartments called organelles to carry out specialised metabolic functions. Researchers at University of Basel, Switzerland, used artificial polymer organelles to upgrade live human cells in a lab dish.
Meier and colleagues coated their polymer vesicles in a chemical that encouraged human white blood cells called macrophages to engulf them. The small capsules contained enzymes, just like natural organelles. The enzymes chosen produced fluorescent chemicals, signalling they were working without problems inside their new host.
The artificial organelle’s membrane can be chemically tuned to control which chemicals can pass through it and regulate the reactions inside, according to Wolfgang Meier, one of the researchers. “We call it a ‘nanoreactor’,” he says.
At 200 nanometres across, the organelles are 400 times smaller in width than a human hair.
Meier says the artificial organelles would also work in other human cells, opening up the possibility of a new cancer therapy that tricks diseased cells into poisoning themselves from the inside out…
Although the immediate interest is in drug delivery, the researchers involved are mindful that more sophisticated artificial organelles could provide metabolic services beyond the natural human repertoire.
Artificial organelles might also be able to treat conditions caused by a deficit of a particular enzyme. For example, someone with lactose intolerance could have their digestive cells given artificial organelles containing lactose-digesting enzymes.
In the far future, it might be possible to introduce non-human metabolic functions into human cells. “We could, in principle, bring in a nanoreactor that [lets] your skin do something like photosynthesis. So if you are hungry, you just lie in the Sun,” says Meier.
The research was published in Nano Letters (abstract).
—Jim
