Patients with this type of cancer have poor prognosis and there is currently no known treatment which is effective. Researchers at SIR’s 35th Annual Scientific Meeting in Tampa, USA, presented preliminary results of an animal study in which gold nanoparticles were surface functionalised with anti-sense oligonucleotides to target molecular mechanisms of pancreatic ductal adenocarcinoma. They proposed transcatheter intra-arterial delivery of these nanoparticles, a procedure termed “nanoembolisation”, as a novel therapy for the disease.
“As current treatments for pancreatic cancer offer minimal benefit, entirely new approaches are needed. We have developed a radically different approach that might be able to overcome some of the obstacles that have hampered previous therapies for pancreatic cancer,” said Reed A Omary, an interventional radiologist and professor of radiology and biomedical engineering at Northwestern University in Chicago, USA.
Traditional treatment of pancreatic cancer typically includes some combination of chemotherapy, radiation therapy, and/or surgery. However, none of these methods results in effective treatment.
Instead, Northwestern researchers constructed gold nanoparticles measuring about13 nanometres in diameter. In animal studies, the research team used an interventional radiology technique to inject the cancer-killing nanoparticles directly into the tumour. Of 12 rabbits with pancreatic tumours, six were treated by traditional intravenous delivery with the gold nanoparticles, and six by nanoembolisation. Then, the concentration of nanoparticles within the tumour was compared in both groups.
Researchers found that there was a dramatic increase of the concentration of gold nanoparticles in the tumours of the rabbits which received nanoembolisation over those that received intravenous injection. The nanoembolisation group had approximately 89 times as much in the tumour core, 38 times as much in the tumour periphery and 55 times as much in the tumour combined. Omary said, “Using nanoembolisation, we dramatically increased the concentration of the nanoparticles in the tumour by 55 times over traditional methods that use a vein.”
Researchers in the study concluded that image-guided nanoembolisation dramatically increases intra-tumoural uptake of therapeutic gold nanoparticles over systemic intravenous administration in a rabbit model of pancreatic cancer. This could mean nanoembolisation represents a novel pancreas-directed local approach for interventional radiologists to treat this type of cancer.
“As current treatments offer minimal benefit, entirely new approaches are needed,” said Omary, in explaining the pre-clinical study. A major reason that current pancreatic cancer treatments do not work is that scar tissue develops around the cancer. This scar tissue blocks cancer-killing drugs from entering the tumour in the first place, said Omary. “We used a catheter to deliver cancer-killing nanoparticles directly to the tumour. The catheter is placed into an artery near the groin and navigated through blood vessels to the site of the tumour. Once in the blood vessel that supplies the tumour, the catheter can deliver nanoparticles directly into the tumour. This method may offer a better way to overcome the scar tissue that blocks drugs from attacking the tumour,” he added.
With this type of catheter delivery, more drug “can go directly where we want it: to the tumour itself,” said Omary. “This is not the case with injections through a vein, where the cancer-killing drug may not end up where it needs to be,” he explained. The direct catheter injections also have the potential to reduce some of the side-effects such as vomiting and hair loss that may be seen with typical chemotherapy. “Researchers have been using the same toolbox for a long time without any benefit; it is time for us to apply some high-tech tools to treat pancreatic cancer,” said Omary, the senior author of “Image-guided nanoembolisation as a novel local therapy for pancreatic cancer: Feasibility in an animal model.”
“For decades, interventional radiology has offered innovative ways to treat cancer patients instead of traditional surgery, chemotherapy or radiation; after all, we invented the field of minimally invasive medicine. Interventional radiologists recognise that the greatest advances in medicine occur at the interface with other medical disciplines,” said Omary.
“Nanoembolisation is a terrific example of bringing together a diverse range of experts—in interventional radiology, chemistry and oncology—to develop a radically different method to treat the cancer with the most dismal survival rate,” he added. Omary praised the efforts of all the Northwestern investigators including nanomedicine experts Chad A Mirkin, director of the university’s International Institute for Nanotechnology and a member of President Obama’s Council of Advisors for Science and Technology, and C Shad Thaxton, assistant professor of urology.
Omary emphasised that before this proposed new treatment is ready for patients, more studies will be needed to show safety and effectiveness.
