A molecular receptor targeted, hydroxyapatite nanocrystal based multi-modal contrast agent.

Multi-modal molecular imaging can significantly improve the potential of non-invasive medical diagnosis by combining basic anatomical descriptions with in-depth phenotypic characteristics of disease. Contrast agents with multifunctional properties that can sense and enhance the signature of specific molecular markers, together with high biocompatibility are essential for combinatorial molecular imaging approaches. Here, we report a multi-modal contrast agent based on hydroxyapatite nanocrystals (nHAp), which is engineered to show simultaneous contrast enhancement for three major molecular imaging techniques such as magnetic resonance imaging (MRI), X-ray imaging and near-infrared (NIR) fluorescence imaging.