You might want to keep a salt shaker with you while reading a June 7, 2016 essay by Matteo Palma (Queen Mary’s University of London) about nanotechnology and DNA on The Conversation website (h/t June 7, 2016 news item on Nanowerk).
This is not a ‘hype’ piece as Palma backs every claim with links to the research while providing a good overview of some very exciting work but the mood is a bit euphoric so you may want to keep the earlier mentioned salt shaker nearby.
Palma offers a very nice beginner introduction especially helpful for someone who only half-remembers their high school biology (from the June 7, 2016 essay)
DNA is one of the most amazing molecules in nature, providing a way to carry the instructions needed to create almost any lifeform on Earth in a microscopic package. Now scientists are finding ways to push DNA even further, using it not just to store information but to create physical components in a range of biological machines.
Deoxyribonucleic acid or “DNA” carries the genetic information that we, and all living organisms, use to function. It typically comes in the form of the famous double-helix shape, made up of two single-stranded DNA molecules folded into a spiral. Each of these is made up of a series of four different types of molecular component: adenine (A), guanine (G), thymine (T), and cytosine (C).
Genes are made up from different sequences of these building block components, and the order in which they appear in a strand of DNA is what encodes genetic information. But by precisely designing different A,G,T and C sequences, scientists have recently been able to develop new ways of folding DNA into different origami shapes, beyond the conventional double helix.
This approach has opened up new possibilities of using DNA beyond its genetic and biological purpose, turning it into a Lego-like material for building objects that are just a few billionths of a metre in diameter (nanoscale). DNA-based materials are now being used for a variety of applications, ranging from templates for electronic nano-devices, to ways of precisely carrying drugs to diseased cells.
He highlights some Canadian work,
Designing electronic devices that are just nanometres in size opens up all sorts of possible applications but makes it harder to spot defects. As a way of dealing with this, researchers at the University of Montreal have used DNA to create ultrasensitive nanoscale thermometers that could help find minuscule hotspots in nanodevices (which would indicate a defect). They could also be used to monitor the temperature inside living cells.
The nanothermometers are made using loops of DNA that act as switches, folding or unfolding in response to temperature changes. This movement can be detected by attaching optical probes to the DNA. The researchers now want to build these nanothermometers into larger DNA devices that can work inside the human body.
He also mentions the nanobots that will heal your body (according to many works of fiction),
Researchers at Harvard Medical School have used DNA to design and build a nanosized robot that acts as a drug delivery vehicle to target specific cells. The nanorobot comes in the form of an open barrel made of DNA, whose two halves are connected by a hinge held shut by special DNA handles. These handles can recognise combinations of specific proteins present on the surface of cells, including ones associated with diseases.
When the robot comes into contact with the right cells, it opens the container and delivers its cargo. When applied to a mixture of healthy and cancerous human blood cells, these robots showed the ability to target and kill half of the cancer cells, while the healthy cells were left unharmed.
Palma is describing a very exciting development and there are many teams worldwide working on ways to make drugs more effective and less side effect-ridden. However there does seem to be a bit of a problem with targeted drug delivery as noted in my April 27, 2016 posting,
According to an April 27, 2016 news item on Nanowerk researchers at the University of Toronto (Canada) along with their collaborators in the US (Harvard Medical School) and Japan (University of Tokyo) have determined that less than 1% of nanoparticle-based drugs reach their intended destination …
Less than 1%? Admittedly, nanoparticles are not the same as nanobots but the problem is in the delivery, from my April 27, 2016 posting,
… the authors argue that, in order to increase nanoparticle delivery efficiency, a systematic and coordinated long-term strategy is necessary. To build a strong foundation for the field of cancer nanomedicine, researchers will need to understand a lot more about the interactions between nanoparticles and the body’s various organs than they do today. …
I imagine nanobots will suffer a similar fate since the actual delivery mechanism to a targeted cell is still a mystery.
I quite enjoyed Palma’s essay and appreciated the links he provided. My only proviso, keep a salt shaker nearby. That rosy future is going take a while to get here.