Nanoparticles to awaken immunity system to fight cancer

In an approach to fight cancer, researchers have found that though small, nanoparticles can pack large payloads of a variety of agents which have different effects that activate and strengthen the body's immune system response against tumours.

"Our lab's approach differs from most in that we use nanoparticles to stimulate the immune system to attack tumours and there are a variety of potential ways that can be done," said Steve Fiering, professor at Dartmouth College in the US.

"Perhaps the most exciting potential of nanoparticles is that although very small, they can combine multiple therapeutic agents," Fiering said.

Tumours protect themselves by tricking the immune system into accepting everything as normal, even while cancer cells are dividing and spreading.

Nanoparticles are too small to imagine. One billion could fit on the head of a pin. This makes them stealthy enough to penetrate cancer cells with therapeutic agents such as antibodies, drugs, vaccine type viruses, or even metallic particles.

The immune therapy methods limit a tumour's ability to trick the immune system. It helps it to recognise the threat and equip it to effectively attack the tumour with more "soldier" cells.

Fiering is testing the use of heat in combination with nanoparticles. An inactive metallic nanoparticle containing iron, silver, or gold is absorbed by a cancer cell.

Then the nanoparticle is activated using magnetic energy, infrared light, or radio waves. The interaction creates heat that kills cancer cells. The heat, when precisely applied, can prompt the immune system to kill cancer cells that have not been heated.

The key to this approach is minimising healthy tissue damage while maximising cancerous tumour destruction of the sort that improves recognition of the tumour by the immune system.

The review appeared in the journal WIREs Nanomedicine and Nanobiotechnology.