Towards more sensitive MRI
MRI is a powerful medical imaging technique used in radiology to investigate the physiology of the human body. It uses a magnetic field and radiofrequency pulses to make pictures of organs and structures. Its widespread use in various clinical and scientific applications has attracted great interest in improving its sensitivity mainly for cancer diagnosis. Several contrast agents have been developed for detecting tumours but these are still not ready for translational applications in vivo. The EU-funded UHMSNMRI (Design and testing of Gd3+-Loaded Ultrasmall Hollow Mesoporous Silica Nanosphere Platform as High Sensitivity Probes for Targeted Magnetic Resonance Imaging of Tumor In Vivo) project proposed to develop nanoparticle-based contrast agents coated with gadolinium. The synthesised silica nanoparticles have a diameter of 30nm and a fluorescein dye embedded in their framework, which allows visualisation of the nanoparticles with the cells. In addition to gadolinium, the surface of the UHMSNMRI nanoparticles contains the RGD ligand that targets the integrin - αvβ3. Researchers tested the resultant nanoprobe in human malignant glioma cells by fluorescence and MR imaging and they found very low cytotoxicity and high integrin-binding affinity and specificity. Within six hours after intravenous administration into mice bearing human tumours, scientists were able to visualise the nanoprobes in the tumours. Taken together, these results highlighted the utilisation of integrin-targeting contrast agents for highly sensitive imaging studies that could easily translate into biomedical applications.
