A step toward minute factories that produce medicine inside the body

Jun 27, 2012
A step toward minute factories that produce medicine inside the body

Scientists are reporting an advance toward treating disease with minute capsules containing not drugs — but the DNA and other biological machinery for making the drug. In an article in ACS' journal Nano Letters, they describe engineering micro- and nano-sized capsules that contain the genetically coded instructions, plus the read-out gear and assembly line for protein synthesis that can be switched on with an external signal.

Daniel Anderson and colleagues explain that development of nanoscale production units for protein-based drugs in the human body may provide a new approach for treating disease. These production units could be turned on when needed, producing medicines that cannot be taken orally or are toxic and would harm other parts of the body. Until now, researchers have only done this with live bacteria that were designed to make proteins at disease sites. But unlike bacterial systems, artificial ones are modular, and it is easier to modify them. That's why Anderson's group developed an artificial, remotely activated nanoparticle system containing DNA and the other "parts" necessary to make proteins, which are the workhorses of the human cell and are often used as drugs.

They describe the nanoscale production units, which are tiny spheres encapsulating protein-making machinery like that found in living cells. The resulting nanoparticles produced active proteins on demand when the researchers shined a laser light on them. The nanoparticles even worked when they were injected into mice, which are stand-ins for humans in the laboratory, producing proteins when a laser was shone onto the animals. This innovation "may find utility in the localized delivery of therapeutics," say the researchers.

Explore further: Chemists design nanoparticles that can deliver three cancer drugs at a time

More information: "Remotely Activated Protein-Producing Nanoparticles”, Nano Lett., 2012, 12 (6), pp 2685–2689. DOI: 10.1021/nl2036047

Abstract
The development of responsive nanomaterials, nanoscale systems that actively respond to stimuli, is one general goal of nanotechnology. Here we develop nanoparticles that can be controllably triggered to synthesize proteins. The nanoparticles consist of lipid vesicles filled with the cellular machinery responsible for transcription and translation, including amino acids, ribosomes, and DNA caged with a photolabile protecting group. These particles served as nanofactories capable of producing proteins including green fluorescent protein (GFP) and enzymatically active luciferase. In vitro and in vivo, protein synthesis was spatially and temporally controllable, and could be initiated by irradiating micrometer-scale regions on the time scale of milliseconds. The ability to control protein synthesis inside nanomaterials may enable new strategies to facilitate the study of orthogonal proteins in a confined environment and for remotely activated drug delivery.

Related Stories

Nano-sized 'factories' churn out proteins

Apr 09, 2012

Drugs made of protein have shown promise in treating cancer, but they are difficult to deliver because the body usually breaks down proteins before they reach their destination.

Using living cells as an 'invisibility cloak'

Jun 15, 2011

The quest for better ways of encapsulating medicine so that it can reach diseased parts of the body has led scientists to harness -- for the first time -- living human cells to produce natural capsules with ...

Genetically engineered spider silk for gene therapy

Aug 10, 2011

Genetically engineered spider silk could help overcome a major barrier to the use of gene therapy in everyday medicine, according to a new study that reported development and successful initial laboratory ...

Recommended for you

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

antialias_physorg
not rated yet Jun 27, 2012
But unlike bacterial systems, artificial ones are modular, and it is easier to modify them.

Can you say 'biohacking'?

Now they (whoever 'they' is in that context) won't need to have biological weapons - they can just subvert such machines for their uses.

Or if you want to be really paranoid about it: Douse a country's populace with such (latent) toxin-microfabrication units (or just the ruling elite) and you have them by the balls. Forever.
Jaeherys
not rated yet Jun 27, 2012
Can you say 'biohacking'?

Without more information of this liposome like structure it would be difficult to tell just how easy or hard it would be to
'hack' it.

Liposomes usually enter the cell which would make it extremely hard to a) find which cells they are located in and b) modify the genetic material by either bacterial or viral interaction.

I'm assuming very minimal signal induction and recognition proteins/molecules have been added which would probably make it very hard to identify these liposomes from normal membranes even if somehow a bacterium had accidentally ingested it.
Jaeherys
not rated yet Jun 27, 2012
con't
Of course there are ways to modify these with viruses infecting a cell, producing proteins to recognize these liposomes in the cytoplasm and then modify its genetic material. But again you run into the same issues as above.

Luckily for us though, there is a matter of the instability of liposomes in biological environments.

From http://www.liposo...ity.html


Biological stability of liposomes is limited. Cationic liposomes in plasma are prone to aggregation and exhibit leakage. High density lipoproteins (HDLs) are responsible for destabilization of liposomes prior to interaction of liposomes with circulating phagocytic cells such as monocytes. The destabilization of liposomes is due to the lipid exchange between the liposomes and HDLs.


This hampers both long term 'enslavement' of humans by potentially toxic liposomes by preventing successful modification of enough genetic material to produce the desired effect.
antialias_physorg
not rated yet Jun 27, 2012
Without more information of this liposome like structure it would be difficult to tell just how easy or hard it would be to
'hack' it.

I'm not sure if a structure that big would be able to pass through a cell wall. It seems that the structure is almost the same order of magnitude as a cell (or at least a mitochonrdium)
The article says they can be activated by laserlight. Imagine such a factory for insulin production (which would be great for people who suffer from diabetes) but could be activated by 'unauthorized persons' and would send the patient into an (hypoglycemic) insulin shock.
Jaeherys
not rated yet Jun 27, 2012
I'm not sure if a structure that big would be able to pass through a cell wall. It seems that the structure is almost the same order of magnitude as a cell (or at least a mitochonrdium)


If you use the upper size then for sure, it would be too large to envelope but that seems excessively large for such a "simple" mechanism.

And I see now what you mean by hacking; not just an actual change of DNA.

Either way, these would only last a few days in the body which would significantly reduce the chance for unauthorized activation as you'd have to be given injections of this every 1.5 days or so.
Moreover, it would seem that the purpose of this is to deliver the drug exactly where it is required and when it is required by means of some sort of membrane association and localized production.

It'd probably be easier to use a virus to edit the hosts DNA so that you can control the production of some toxin when you want. That would be game over for us and more or less permanent!

More news stories

Making 'bucky-balls' in spin-out's sights

(Phys.org) —A new Oxford spin-out firm is targeting the difficult challenge of manufacturing fullerenes, known as 'bucky-balls' because of their spherical shape, a type of carbon nanomaterial which, like ...

Melting during cooling period

(Phys.org) —A University of Maine research team says stratification of the North Atlantic Ocean contributed to summer warming and glacial melting in Scotland during the period recognized for abrupt cooling ...