Molecular imaging is rapidly developing as a powerful tool in research and medical diagnostic. By integrating complementary signal reporters into a single nanoparticulate contrast agent, multimodal molecular imaging can be performed as scalable images with high sensitivity, resolution and specificity. In this review, multifunctional nanoparticles (MFNPs) are classified into four types: conjugation, encapsulation, core/shell, and co-doping. Further, new constructs of MFNPs were reported recently which have used nanoparticulate contrast agent such as quantum dots (QDs), iron oxide nanoparticles (IONPs), Upconversion nanoparticles (UCNPs), carbon based nanoparticles, gold nanoparticles (Au-NPs), Metal-Organic Frameworks (MOFs), dendrimers and porphyrins based nanoparticles. Different surface modification strategies were also developed as well as ligands are attached to those NPs to render the biocompatibility and enable specific targeting. These new development in MFNPs are expected to introduce a paradigm shift in multi-modal molecular imaging and thereby opening up an era of personalized medicine and new diagnostic medical imaging tools.
Keywords: Multimodal Imaging; Molecular Imaging; Multifunctional Nanoparticles; Contrast Agents; Surface Functionalization; Theranostic.