Philips leads SonoDrugs project

A major European project aimed at advancing image-guided drug-delivery techniques could improve the future treatment of illnesses such as cancer and cardiovascular disease.

Led by Royal Philips Electronics, the four-year SonoDrugs project intends to develop a minimally invasive treatment that will carry drugs to the site of disease and deliver them using ultrasound pulses (The Engineer, 15 October 2008). According to Philips, localising drug delivery in this way improves effectiveness and reduces the side effects associated with ‘whole-body’ dosing.

Researchers at Philips have been assessing the use of ultra-sound guidance for the treatment of cardiovascular diseases for several years. However, with a budget of €15.9m (£14.4m — €10.9m of which is being funded under the European Union’s [EU’s] 7th Framework programme), the project has expanded its study to include the use Magnetic Resonance Imaging (MRI) in the treatment of oncological illnesses.

The technique simultaneously uses real-time MRI to image the patient’s organs, detect the arrival of the drug-loaded particles at the disease site, measure the local heating effect of the ultrasound pulses, and monitor the temperature-triggered release of drugs from the particles.

The MRI-labelled drug-loaded particles are typically 100nm to 200nm in diameter, which allows them to penetrate deep into the tissue through the small capillaries in the vascular system. Once in location, heat is applied at just a few degrees above normal body temperature to release the drug into the diseased tissue.

Jochen Keupp, a Philips researcher, said: ‘You can imagine that the physiological range of heat is very small. You should not heat the body tissue above 40°C. At 42°C you can do permanent damage so we need to be very accurate. This is where MRI has a big advantage, because it is able to monitor temperature changes very precisely.’

MRI will also be used to screen drug delivery. He added: ‘Not only do we want to track the temperature but also the drug release on the carrier side. The idea is to use MRI in combination with the corresponding label on the carrier to see where the agents go with the drugs.

Drugs could be administered in fairly high doses, with the MRI?tuned to visualise the relevant concentration in the blood, said Keupp. MRI’s ability to locate particles labelled with MR contrast agents, such as gadolinium or manganese, could provide doctors with greater information regarding lesion location, drug release and ultrasound focusing. Research activities in this field will initially focus on the treatment of cancers, however, Keupp said that in the future both ultrasound and MRI imaging could be used for other illnesses that require targeted treatment.

He added: ‘For any disease where a specific organ is affected, or you want to localise your drug then this will be very useful. Globally, this project is attracting a lot of interest in the research domain. There are currently no products available for external drug release.’

Working alongside 15 industrial partners, university medical centres and academic institutions from throughout the EU, Philips has already integrated the necessary hardware into its HIFU (High Intensity Focused Ultrasound) MRI research system.

Philips hopes to provide proof of principle for the carrier within four years, with the procedure ready for market in the next 10 years.

Ellie Zolfagharifard