A new tool in the fight against cancer? A considerable achievement by Slovenian scientists

A research team has developed a new, highly efficient drug-delivery system based on magnetic iron oxide nanoparticle clusters encapsulated inside a liposome.

Nature Nanotechnology, November 2011 - Vol 6 No 11 (the cover)

October 2011

The team, led by Dr Olga Vasiljeva and Dr Boris Turk from the Jožef Štefan Institute and including researchers from the Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, the Centre of Excellence in Nanoscience and Nanotechnology, the Centre of Excellence in the fields of Chemistry, Biochemistry, Physics and Pharmacy, and the Faculty of Chemistry and Chemical Technology of the University of Ljubljana, has developed a new, highly efficient drug-delivery system based on magnetic iron oxide nanoparticle clusters encapsulated inside a liposome.

Using an animal model of human breast cancer, the researchers demonstrated considerably improved effects of the standard cancer chemotherapy drug doxorubicin. At the same time, they also demonstrated the efficient delivery of a protease inhibitor, which inhibited tumour growth considerably.

The work of the Slovenian scientists has been published in the renowned science magazine Nature Nanotechnology . The achievement is especially important because it may pave the way for a new efficient tool in the fight against cancer.

Liposomes can be directed to the tumour and its microenvironment by an external magnet, improving the effectiveness of existing cancer treatments

One of the figures from the article.

This is a new, efficient drug-delivery system, which, according to experiments performed on animals to date, effectively limits the growth of mammary tumours and has a similar effect on other types of cancerous tumour. The system is based on magnetic iron oxide nanoparticle clusters encapsulated in a liposome. Slovenian scientists have succeeded in loading nanoparticles with an active substance or encapsulating the drug independently from nanoparticles. They encapsulated them into liposomes or ferri-liposomes, which are sensitive to a magnetic field. With the help of an external magnet, they directed drug-loaded ferri-liposomes to the tumour and its microenvironment in transgenic mice. Because the new nanoparticles have outstanding contrast properties, they can be detected and visualised by MRI scanning and used for non-invasive monitoring of drug delivery to cancerous tumour cells in vivo.

The tests conducted on mice showed that, compared to the control group, tumours reduced substantially in animals injected with ferri-liposomes carrying nanoparticles, even after a single-dose treatment. The preliminary toxicity tests showed that the nano-carriers of drugs do not accumulate in the body but are excreted through the kidneys, which means that the Slovenian scientists have succeeded in overcoming all three major problems compromising existing chemotherapy cancer treatment; with successful targeted drug-delivery, they have prevented the drug from having toxic effects in healthy parts of the body and increased its bioaccessibility and treatment efficiency.

Text by Vesna Žarkovič, Sinfo, October 2011 

Photo: IJS archives