Inorganic nanomaterials for tumor angiogenesis imaging

Tumor angiogenesis plays an important role in cancer development and metastasis. Noninvasive detection of angiogenic activities is thus of great importance in cancer diagnosis as well as evaluation of cancer therapeutic responses. Various angiogenesis-related molecular targets have been identified and used in tumor vasculature targeting and imaging. Recently, inorganic nanomaterials with various unique intrinsic physical properties have attracted growing interest in biomedical imaging applications. This article will review current progresses in the applications of inorganic nanoprobes in molecular angiogenesis imaging.

Several types of nanomaterials with various optical properties, including semiconductor quantum dots (QDs), single-walled carbon nanotubes (SWNTs), upconversion nanoparticles (UCNPs), and surface-enhanced Raman scattering (SERS) nanoparticles, have been used as novel optical probes to image angiogenic events. Besides optical imaging, magnetic resonance imaging (MRI) of angiogenesis using magnetic nanoparticles has also been intensively investigated. Moreover, nanomaterials provide unique platforms for the integration of various imaging modalities together with therapeutic functionalities for multi-modality imaging and therapy.

Although the application of inorganic nanomaterials in clinical imaging and diagnosis is still facing many challenges, the unique properties and functions of these novel nanoprobes make them very promising agents in angiogenesis imaging and could bring great opportunities to this fast-growing field.