At UNSW’s Centre for Advanced Macromolecular Design, Professor Martina Stenzel leads a research team building a range of remarkable polymer nanoparticles, precisely engineered to distinguish between cancer cells and healthy tissue.
By successfully identifying and attaching to cancer cells, these nanoparticles – with diameters more than 1,000 times smaller than the point of a needle – show promise as new, non-toxic drug delivery systems that could overcome the debilitating effects of conventional cancer treatments, which do not spare healthy cells.
The group has achieved encouraging results in two key areas: they have engineered a range of nanoparticles that have been successfully deployed in the lab to deliver drugs to destroy specific cancer cells, and they have enabled these nanoparticles to ‘find’ cancer cells among healthy tissue by accurately penetrating an artificial tumour, mimicking how the disease manifests in the human body.
By putting these two capabilities together, new drug delivery systems are in development for a range of cancers including prostate, breast, ovarian and pancreatic.
While polymers are usually associated with household and industrial plastics, Stenzel says they can be particularly useful in medicine because they respond to environmental signals like heat, light and pH levels. This means they are easier to direct than more conventional materials like metals and porcelain. Many biopolymers, like cellulose and proteins, also form the building blocks of nature and their use in the human body – as dissolvable sutures, for example – is well established.
To work out how to isolate diseased cells, Stenzel collaborates with medical researchers who have identified the unique receptors on the surface of various cancer cells. She loads her polymer nanoparticles with the right ‘key’ – often something as simple as a sugar molecule – to latch onto a particular cancer cell’s receptors. Delivered into the bloodstream, the nanoparticles remain intact, only releasing their pharmaceutical load once they reach their target.
“The inside of a cell is a very different environment from the bloodstream. It’s very aggressive and we can use this to trigger the release of the drug once the nanoparticle has arrived,” says Stenzel, who is recognised internationally as the leading expert in synthesis of novel polymer architecture.
“I have always been interested in the medical aspects of polymer science, so making the jump to drug delivery systems is very exciting,” she says.
Arriving in Australia 15 years ago from Germany with plans to spend a year on post-doctoral research while she improved her English, Stenzel has since settled here permanently and built one of world’s foremost research groups in her field.
“I am working at the junction of chemistry and medicine. While chemistry can seem quite straightforward the body is very complicated so I am constantly learning – something I really enjoy,” she says.
Her work has been recognised with two major awards, Le Fèvre Memorial Prize from the Australian Academy of Science and a NSW Science and Engineering Award.