[nanoPost] Quantum dot-based nanobioprobes for multimodal imaging and biomedical diagnostics

Research Centre Japan

The present study describes an original approach in the synthesis of quantum dots allowing a development of novel
hybrid nanobiomaterials with small size (up to 20-30 nm in diameter) and dual or multimodal properties (e.g.,
fluorescent, paramagnetic, radioactive, photosensitizing, etc.), as well as their intracellular delivery, cytotoxicity, and
potential for application in biomedical imaging and diagnostics. The described hybrid nanoparticles are synthesized on
the basis of silica-shelled single quantum dot micelles. The obtained products consist in approximately 92% of single
nanocrystal (quantum dot) into one silica sphere. The presence of hydrophobic layer between the QD and silica-shell
ensures an incorporation of other hydrophobic molecules in the close proximity of nanocrystal. Thus, it is possible to
combine the characteristics of hybrid materials with the priority of small size. The silica-shelled single quantum dot
micelles are considered as a basis for fabrication of new generation contrast agents with dual and multimodal imaging
properties – appropriate for simultaneous deep-tissue imaging, using different imaging techniques [e.g., optical imaging,
magnetic resonance imaging (MRI), positron emission tomography (PET), X-ray, etc.]. Novel multimodal imaging probes
(for simultaneous optical and MRI imaging, as well as for sensitizing of cancer cells to light irradiation, Figure 1) will be
introduced. These novel quantum dot-based hybrid nanomaterials show an ability for intracellular delivery, which makes
them appropriate for cell tracing and drug delivery.