Pretargeting nanoparticle strategies for multimodal imaging of tumours

Imaging of diseases inside the body is becoming a very important part of patient management, especially in cancer and heart disease. Imaging can reveal the extent of disease, and measure the response to treatment, without biopsy or surgery. PET scanners, gamma cameras and MRI scanners are all now routine facilities in hospitals. In this project we will prepare a new generation of contrast agents or radioactive tracers that can be injected into the patient, and will migrate through the body to reach the site of disease, where they will bind. Once the tracer molecules have cleared from the rest of the body, the scanner can detect the present of the remaining tracer molecules in the disease site (e.g. tumour) and thus make an image of the location of disease. The project aims to develop a new system for getting the contrast agent into the target tissue, to obtain clearer and more informative images with greater specificity and lower toxicity and radition dose for the patient. The new system will also have the benefit of being more cost-effective because there will be much less complex processing of the radiotracer on the day of use in the hospital. The new system involves first injecting non-radioactive non-contrast particles into the patient. These will locate in the tumour or disease site and clear from the rest of the body. Then a contrast agent or radiotracer is injected which will seek out the particles and bind to them. Because each particle can bind many tracer molecules, more contrast can be delivered to the target in this way. To achieve this we will develop both the particles themselves and a new set of radiotracers and contrast agents to bind to them, for imaging with a PET scanner, gamma camera or MRI scanner. The new system will be applicable in cancer, heart disease and many other conditions. It can be used not only to image disease but also to treat cancer, if the radiotracer is replaced with a more toxic form of radioactivity. Thus the toxic radioactivity will be delivered selectively to the tumour, so that tumour cells can be killed with minimal harm to normal tissues.