Iodinated silica/porphyrin hybrid nanoparticles for X-ray computed tomography/fluorescence dual-modal imaging of tumors

Silica nanoparticles containing covalently linked iodine and a near-infrared (NIR) fluorescence dye, namely porphyrin, have been synthesized through a one-pot sol–gel reaction. These particles are called iodinated silica/porphyrin hybrid nanoparticles (ISP HNPs). The ISP HNPs have both high X-ray absorption coefficient and NIR fluorescence. The ISP HNPs modified with folic acid (FA) and polyethylene glycol (PEG), denoted as FA-PEG-ISP HNPs, enabled the successful visualization of tumors in mice by both X-ray computed tomography (CT) and fluorescence imaging (FI). Thus, the FA-PEG-ISP HNPs are useful as contrast agents or probes for CT/FI dual-modal imaging.