By mimicking the human body’s natural elastic behaviour, researchers are developing nanogels that reduce their size and are able to drop drugs into previously inaccessible cancerous tissues.
In 10 seconds? Scientists have created drug delivery nanogels that carry medicines right into cancer cells. Responding to the temperature of tumours, that were heated up by clinicians, the gels shrink and pass through tiny pores in blood vessels to drop their load. (Read the science)
What did the researchers find out to make this possible? Well, to deliver anti-cancer agents to tumours, nanoparticles travelling in the bloodstream have to pass through the pores of blood vessels. But only particles of the correct size can get through. To solve the problem, scientists used the features of human elastin. This protein helps tissues regain their shape after stretching or piercing. They’ve added elastin’s ‘building block’, human tropoelastin to nanogels. The idea was that the nanogel would shrink if heated up, and it worked! (Read my research paper)
And how did they produce this nanogel? Good question! Elastin needed to be incorporated into a three-dimensional structure to get a ‘shrinkable’ nanogel. To accomplish this, the researchers genetically-engineered bacteria to produce a protein with both elastin and silk. The silk units came together and linked with one another, allowing a 3D nanogel structure to form. This combination utilizes the strength of silk with the heat-responsiveness of human tropoelastin. (Read more)
So, how does it work? The silk and elastin combination allows the nanogel to shrink when reacting to heat. While travelling through the bloodstream, it remains expanded, and is therefore too large to pass through blood vessel pores and enter healthy tissues. But when it arrives at a heated tumour, the nanogel “shrinks”, making it just the right size to carry through anticancer drugs that kill the tumour. (Find out more)
I also heard about nanoparticles directly attacking tumours… True, other researchers have created hybrid nanoparticles containing dopamine-based polymers and coated them with a substance that protected them from immune cells. These particles found their way to tumours. When the tumours were ‘lit up’ with near infrared light, they converted that light to heat and started destroying cancer cells. (Read more)
Amazing! What can we expect in future? While this research is only in the preliminary stages, these nanogel systems will soon be combined with many state-of-the-art tumour heating techniques (like ultrasound) to help place drugs right at tumours. As this research progresses, we are hopeful that we can improve chemotherapy treatments and simultaneously reduce side effects. (Read more)
Using nanotech to starve out tumours
The same silk- and elastin-based polymers that are used to develop drug-carrying nanogels are also being investigated for their macro-scale properties.
If the polymers are placed in a water-based solution at a high enough concentration, the entire solution can transition from a liquid state to a solid state upon heating.
This liquid-to-solid property is currently being investigated for use as an injectable embolic, where blood vessels can be sealed off and restrict tumours from their nutrient supply.
Kyle is the author of the main research paper and PhD Candidate in Bioengineering at the University of Utah. He is also the founder of Ike Scientific, LLC, a scientific consulting firm.