Researchers at the University of California have modified E-coli cells to make them more resistant and able to enter tumours, without replicating. They can also be used for a range of other purposes.
Synthetic biology (which aims to create living, functioning microorganisms using genetic engineering and other advanced techniques) has reached a new milestone: cyborg cells. These are hybrids made by modifying the structure of certain bacteria to carry out tasks like synthesising drugs, sanitising air, purifying contaminated water, diagnosing certain diseases, and more.
This is reported in the journal Advanced Science, which has published a study by researchers at the University of California, Davis, explaining the features of the new bionic cells.
In short, bioengineers have managed to insert 3-D structures made of hydrogel polymers (molecules made up of identical ‘units') into living E-coli bacterial cells, preventing them from replicating. Thus, the Cyborg Cells - as they’ve been called – still have all the advantages of living organisms, like metabolism, mobility, protein synthesis and the ability to 'express' the instructions embedded in their DNA, but without being able to reproduce, and therefore without exposing the environment in which they are released to various kinds of risks.
More functions
At the same time, these new Cyborg Cells can overcome the limits of other experimental cells in the same 'category', but which are totally synthetic (i.e. that do not originate from bacteria) and which are only able to perform, at least for the moment, a few elementary functions.
Hybrids exploit the potential of the two approaches, which is why they could be very successful in biomedical research and perform a wide range of tasks.
This is because the presence of polymers increases their resistance to external agents, like mechanical or physical stresses (e.g. changes in pH or temperature, or the presence of antibiotics or hydrogen peroxide), making them particularly suitable for carrying out difficult tasks in hostile environments.
One of the versions of the Cyborg Cells tested by the Californian group may also become a cancer treatment, because it can penetrate diseased cells and destroy them - at least, this is what has been seen in early laboratory studies.
Medicine and ethics: some issues
Studies are continuing on various possible polymers that can be used to 'construct' Cyborg Cells, on external controls on their activities and potential applications. But experiments like this also pose ethical questions, which will have to be addressed: is it right to use living beings like bacteria and turn them into a kind of machine, for our use and consumption?
The safety levels of these hybrid organisms will then have to undergo further checks, to prevent them from unexpectedly replicating in some way.
