Category Archives: chemistry

Nanobot twofers for cancer treatment

'nano nano!'

‘nano nano!’

In case you don’t watch as much bad TV as me, you may not know what a ‘twofer’ is. As the great Jessica Simpson says ‘everybody loves a twofer’ – a twofer being something that has two uses, for the price of one. She was of course referring to a top that is also a dress, or trousers that unzip as shorts…but this is about a medical marvel, a twofer that might just save you life one day.

Recently pulblished in the Journal of the American chemical society is a research paper describing the development of a rattle-structured multifunctional up-conversion core/porous silica shell nanotheranostic. Wow, that’s a mouthful! From now on lets call them twofer nanobots  – now let me break them down for you!

TEM images showing the core/shell structure

The nanobots are tiny balls of exotic rare earth mixtures made to be of a uniform size around 25 nanometers (human hair would be 60,000 nanometers) with a hole in the centre (core).

Next, a little gadolinium (Gd) is added before the balls are coated with a silica coating until they are around 50 nanometers in size. Each of these parts has an important part to play…

There are at the moment two major methods to treat cancer; (1) chemotherapy, where a drug is used to destroy the tumor and; (2) radiotherapy where x-rays are used to similar effect.

There are problems associated with both; chemotherapy requires high doses which causes a lot of pain as well as damage to non-cancerous cells. Some tumors such as hypoxic tumors can also have a very high tolerance to radiation.

What if you could transport the chemotherapy drug into the tumor directly? This would reduce the dose and damage to healthy cells. What if you could find a way to make hypoxic tumors respond to radiotherapy? What if, along with this you could also image the tumor?

Enter the nanbot twofer! No, wait now its a threefer (chemo, radio, imaging) are there no end to nanobots talents?!

The core is used to transport chemotherapy drugs into the tumor, the gadolinium allows the nanobot to be seen inside the tumor so you can image alongside treatment, the same drugs can be also be used as a radiosensitizer to improve the effectiveness of the radiotherapy. The silica shell is added to improve biocompatibility, so that it isn’t rejected by the body, and to make sure the nanobots dont clump together.

So that’s chemotherapy, radiotherapy and imaging in one smart nanobot, take that cancer!