What’s so special about nanoparticles?
Most biological interactions occur at the nano level, or in other words, at a scale one billionth the size of a meter. This means that being able to manipulate nanomaterials of a similar size is extremely useful and applicable to a wide range of medicine.
Due to their minuscule size, nanoparticles have a high surface area to volume ratio, giving them a large contact area when interacting with their targets. Lots of different functional groups can be added to this surface area, allowing for a diverse set of chemical functionalities.
Research into nanotechnology is rapidly gaining pace, and many ideas once believed to be in the realms of science fiction are being explored in labs with the goal of being used in human medicine. Here are five interesting examples of how nanotech is changing medicine:
1. A superweapon against drug-resistant bacteria?
Antibiotic drug resistance is a real and growing threat to public health. The overuse of antibiotics has led to the evolution of ‘superbugs’ such as MRSA which are in some cases resistant to almost all known antibiotics. Examples have been seen where antibiotics that were being saved as the last line of defence are now rendered useless.
There are genuine fears amongst some in the scientific community that antibiotic resistance could throw us back into a medical dark age where even minor infections could be fatal – but nanotechnology could be the answer.
Nanoparticles are small enough to effectively act as molecules when they interact with cells. They can pass through the cell membranes of bacteria, allowing them to cause havoc with the bacteria’s internal functions. One of the ways they do this is by reacting with oxygen inside the bacteria to produce reactive oxygen species.
An excess amount of reactive oxygen species can damage DNA/RNA, disrupt membranes, and produce toxins that interfere with the bacteria’s metabolic activity. By altering membrane permeability and improving the accuracy of drug delivery, nanoparticles can kill the bacteria or give a boost to the traditional drugs that they have become resistant to.
2. Clearer and more accurate imaging of disease?
Due to the very small size of nanoparticles and the different ways they can bind, there are some exciting possibilities to improve the way we carry out medical imaging. Nanoparticles with special properties used for imaging are known as quantum dots, which are able to give a better image than traditional imaging dyes.
Nanoparticles can bind with target sites on cancerous tumour cells, and then produce incredibly accurate images when detected through MRI and ultrasound. They can be manipulated to make the tumour glow, enabling a surgeon to accurately remove only the cancerous cells.
Another application is cardiovascular imaging, where quantum dots can be used to aid with the visualisation of signs of heart disease such as atherosclerosis. Quantum dots can even be attached to proteins that pass through into cells, making it easier to track individual cells than with a dye.
3. A five-minute test for cancer?
Imagine a five-minute test in a pharmacy where a single drop of blood could detect the presence of a huge number of cancers or other diseases. Increasing the availability, speed, and capability of these tests could save countless lives through the early identification of illnesses.
This is known as ‘lab-on-a-chip’ technology, as due to the tiny size of nano-sensors, you can fit a vast number onto a small sensor. Thousands of magnetic nanoparticles can be attached to a single sensor, each in turn attached to antibodies that bind to specific molecules, structures, or microorganisms. Therefore a sensor chip could detect for a vast number of proteins or biomarkers from just a few drops of a patient’s blood.
Expansions in this tech could lead to fast and inexpensive tests available to people who may not otherwise have had access to them. Any patient could walk into a pharmacy or GP and have a couple of droplets put onto the sensor in order to be screened for many illnesses.
4. A fast and accurate way to purify blood?
Magnetic nanoparticles have the potential to purify blood by removing unwanted noxious compounds such as toxins, pathogens, or proteins. This would be done in an outside of the body circuit that could help to purify blood in a similar way to dialysis, but with some key advantages.
Dialysis works by passing a fluid through across a semi-permeable membrane, where unwanted substances are removed by diffusion and ultrafiltration. Purification with nanoparticles would allow for specific substances in the blood to be targeted and removed.
Antibodies or other binding agents can be covalently linked to the nanoparticle surface, which can in turn bond with the target substance in the blood to form an agglomerate. Magnetic fields can then draw the nanoparticle and their bound substance away from the blood.
This could be a valuable tool for helping with problems such as sepsis, or for removing substances that cannot be filtered out via dialysis.
5. Could nanobots even reverse ageing itself?
This one perhaps won’t be changing medicine anytime soon, but is a fascinating area of research nonetheless. Molecular nanotechnology is a highly theoretical field of study looking into nanorobots that could actually re-order matter at a molecular level scale to repair damages and infections.
This is beyond current capabilities, but in the future it could give rise to life extension through the repair of processes thought to be responsible for ageing. Some have theorized that this technology may be able to indefinitely repair and regenerate human tissue.
The scope of what can be achieved in medicine with nanotechnology is vast, and will surely have a growing impact as time and technology progress.
Marcus is a freelance biotechnology writer based in the U.K. Feel free to connect with him on Twitter: https://twitter.com/mrwhitewrites