Fabrication of a multimodal microbubble platform for magnetic resonance, ultrasound and fluorescence imaging application

Magnetic resonance (MR), ultrasound (US) and fluorescence imaging are the widely used diagnostic modalities for various experimental and clinical applications. A multimodal poly(lactic acid) microbubble (MB) integrated with the three imaging modalities was fabricated by adsorbing CdTe quantum dots (QDs) onto the surface and encapsulating superparamagnetic iron oxide (SPIO) nanoparticles into the core. The strong fluorescence of the multimodal MBs confirmed that QDs were successfully deposited onto the surface. The in vitro MRI contrasting capability of the multimodal MBs at various concentrations was evaluated by T2-weighted imaging. Furthermore, the in vitro and in vivo ultrasonography indicated that CdTe and SPIO-inclusive MBs maintained excellent ultrasound contrast property. These results implied that the nano-in-micro hybrid materials have the potential as a nanomedical platform for multimodal bioimaging.