Scientists looking for ways to get minute doses of drugs, so-called "nano-medicines", into the right places in the human body
have turned to "backpacking" bacteria to ferry the cargo.
This week, at the 243rd National Meeting & Exposition of the American Chemical Society (ACS) in San Diego, Dr David H
Gracias, from Johns Hopkins University in Baltimore, Maryland, gave an account of the progress he and his team are making in
this area. Buy Voltaren tabs online without prescription
Gracias told the press:
"Cargo-carrying bacteria may be an answer to a major roadblock in using nano-medicine to prevent, diagnose and treat
disease."
Nano-technology concerns itself with making ultra-tiny devices, small
enough to fit a million or so on the head of a pin. In
medicine the idea is to use them to transport particles of medication,
sensors and other materials to precise locations in the human
body.
But it is not easy to devise self-sustaining motors and propulsion
mechanisms at this scale: so scientists are increasingly turning to
nature, where organisms like bacteria are already of the right scale and
capable of moving on their own.
As Gracias explained:
"Currently, it is hard to engineer microparticles or nanoparticles
capable of self-propelled motion in well-defined trajectories
under biologically relevant conditions."
"Bacteria can do this easily, and we have established that bacteria can carry cargo," he added.
The other advantage with using bacteria is they respond to specific
biochemical signals. It is possible, for instance, to control
their direction and destination in the body so that once they reach
their target, they settle, deposit their "cargo" and grow
naturally.
Bacteria are not strangers to the human body: were are covered with them
on our skin, and our intestines are home to billions of
them. In fact, the total population of bacterial cells we harbour
outnumbers the population of our human cells by 10 to
1.
While the word bacteria may conjure up thoughts of disease and
infection, many are safe and quite harmless, such as the colonies
in our guts that are essential to food digestion.
It is these safe types of gut bacteria that Gracias and colleagues have turned to to find the ideal "beasts of burden" for
transporting nano-materials that have optical, electrical, magnetic, electrical or medicinal properties.
So far, Gracias and his team have tested the backpacking bacteria with various shapes and sizes of "cargo" material. For
example, they have used them to ferry nano-wires, beads and lithographically fabricated nanostructures.
Other teams are also working with bacteria to transport nano-cargoes. For example, one team has made "bacterial carpets" of
large numbers of bacteria to move tiny bits of material.
But Gracias and his team are focusing on getting individual bacteria
cells to transport individual bits of cargo, what they call
"biohybrid devices". The biohybrid devices can move freely with their
cargo backpacks attached.
Gracias said their work is still at a very early, exploratory, stage.
They are experimenting with lots of different things to see
what might prove to be useful with using bacteria as backpackers for
nano-medicines.
"Our next steps would be to test the feasibility of the backpacking bacteria for diagnosing and treating disease in laboratory
experiments. If that proves possible, we would move on to tests in laboratory mice," said Gracias, explaining that:
"This could take a few years to complete."