Imaging techniques including computed
tomography, magnetic resonance
imaging, and positron emission tomography (PET) offer many potential
benefits to diagnosis and treatment of cancers. Each method has its
own strong and weak points. Therefore, multimodal imaging techniques
have been highlighted as an alternative method for overcoming the
limitations of each respective imaging method. In this study, we fabricated
PET/optical activatable imaging probe based on glycol chitosan nanoparticles
(CNPs) for multimodal imaging. To prepare the dual PET/optical probes
based on CNPs, both <sup>64</sup>Cu radiolabeled DOTA complex and
activatable matrix metalloproteinase (MMP)-sensitive peptide were
chemically conjugated onto azide-functionalized CNPs via bio-orthogonal
click chemistry, which was a reaction between azide group and dibenzyl
cyclooctyne. The PET/optical activatable imaging probes were visualized
by PET and optical imaging system. Biodistribution of probes and activity
of MMP were successfully measured in tumor-bearing mice