Microparticle drug delivery

Microparticles and nanoparticles are very small particles, typically less than a hundredth of a millimetre in size.
They have a wide range of applications, one of which is as a way to carry drugs.

Metres to nanometres

How big is a nanometre? We all know it's very small, but exactly how small? To understand this, we can start from something a metre long and keep splitting it into smaller and smaller pieces.

  • If a metre is split into a thousand equal pieces, then each piece is one millimetre long
  • If a millimetre is itself then split into a thousand pieces, then each piece is one micrometre long
  • Finally, if a micrometre is split into a thousand pieces, then each piece is one nanometre long

So, there are a billion (a thousand million) nanometres in a metre.


Normally people define a nanoparticle to be a particle between 1 and 100 nanometres in size, so between a billionth and a ten-millionth of a metre.

They've been used for well over a thousand years to make glittering effects, such as on the surface of pottery.

They have many interesting properties that make them useful in multiple areas, including:

  • Optics - the colour of some nanoparticles change depending on their exact size
  • Catalysis - because of their small size, nanoparticles can be used to speed up some chemical reactions
  • Superconductors - nanoparticles can be used to make high-temperature superconductors
  • Magnetism - making magnets can sometimes be easier with nanoparticles

Micooparticle drugs

Most medical conditions, from headaches to cancer, happen in one particular place in our bodies. Yet most drug treatments simply saturate the whole body with the drug and hope that a small amount gets to where it is needed. A much better approach is design drugs that go directly to the required site.

One exciting way of doing this is to use microparticles or nanoparticles that carry the drug either inside themselves or on their surfaces. This has many advantages such as:

  • Speeding up treatment
  • Protecting the drug from degradation
  • Minimising side effects to other parts of the body
  • Allowing drugs to easily cross the blood-brain barrier

But these drugs can be difficult to make and are often identified as foreign by our bodies and destroyed. Our work is about trying to find ways to avoid this.

Find out more about our work...