One of the major limiting factors in curing cancers is limiting the amount of damage done – by the highly toxic chemotherapy agents – to healthy tissue. A balance has to be created between how much poison is needed to kill the tumour, and how much the body can tolerate.
Nanomedicine – whereby drug molecules are loaded onto miniature carriers which specifically target the cancer cells rather than healthy tissue – has been a Holy Grail. However, nanomedicines to date have had limited success, largely because they are generally uniform in size and shape, unlike the complex and non-spherical shapes that occur in nature and are designed to enter cells.
Now Australian scientists, led by PhD student Chin Wong, from the ARC Centre of Excellence in Convergent Bio Nano Science and Technology (CBNS), have developed a method that allows researchers to (by altering the solvent cocktail) routinely create nanomedicine carriers that are shaped like different types of non-spherical virus or bacteria-like self-assembled structures – simply by creating different cocktails of solvent.
Thanks to the strategies outlined in the paper, published on 1 November 2017 in the journal, Nature Communications, scientists are now able to create nanomedicines – in biologically relevant shapes that have previously been shown to be highly successful in getting to the core of tumours in animal models.
According to CBNS Chief Investigator Professor Pall Thordarson from UNSW “most biological structures are non-spherical such as rods, tubes or ellipsoid but until now it has been difficult for chemists to make non-spherical structures through self-assembly, which is how nanomedicine drugs are traditionally made,” he said.
The research, published on 1 November 2017 in the journal Nature Communications shows how to make non-spherical structures easily and in a predictable fashion using different types of solvent to create desired biological-like shapes. This has direct applications as well as it is already known that non-spherical nanoparticles generally work better in drug delivery for killing tumours than their spherical counterparts. And we already have data (not in this paper) showing our structures go much more easily into artificial tumours than spherical particles.
The research, which was also a collaboration with Professor Martina Stenzel, from UNSW, used cryogenic-transmission electron microscopy (cryo-TEM for short) – the technique that led to the 2017 Nobel Prize in Chemistry. “With the aid of cryo-TEM we were able to show how the polymer molecules are packed together in these structures and confirm that the chemistry we designed worked correctly,” Professor Thordarson said.
Click here to read the paper.
This article was prepared by Tania Ewing, CBNS media consultant.