In vivo monitoring of angiogenesis in a mouse hindlimb ischemia model using fluorescent peptide-based probes.

Vascular endothelial growth factor receptor (VEGFR) and matrix metalloproteinase (MMP) are up-regulated in ischemic tissue and play pivotal roles in promoting angiogenesis. The purpose of the present study was to evaluate two fluorophore-conjugated peptide probes specific to VEGFR and MMP for dual-targeted in vivo monitoring of angiogenesis in a murine model of hindlimb ischemia. To this end, VEGFR-Probe and MMP-Probe were developed by conjugating distinct near-infrared fluorophores to VEGFR-binding and MMP substrate peptides, respectively.

Radioisotope imaging of microRNA-9-regulating neurogenesis using sodium iodide sympoter.

Since microRNAs (miRNA, miR) are known to be critical in various cellular processes and diseases, non-invasive molecular imaging system for miRNA is very important for imaging cellular therapy and disease diagnosis. In this study, we developed a radionuclide imaging system for miR-9 using sodium iodide symporter (NIS). During neuronal differentiation of P 19 cells induced by the treatment of retinoic acid (RA), in vitro and in vivo imaging demonstrated that the expression and activity of NIS from the miR-9 NIS reporter gene was clearly repressed by the increased expression and functional activity of miR-9 that bound with the target sequences in the NIS reporter gene and resulted in destabilized the transcriptional activity of NIS gene, compared with the undifferentiated P19 cells.

A reverse complementary multimodal imaging system to visualize microRNA9-involved neurogenesis using peptide targeting transferrin receptor-conjugated magnetic fluorescence nanoparticles.

Multimodal imaging systems may eliminate the disadvantages of individual imaging modality by providing complementary information about cellular and molecular activites. In this sutdy, we developed a reverse complementary multimodal imaging system to image microRNAs (miRNA, miR) during neurognesis using transferrin receptor (TfR) and a magnetic fluorescence (MF) nanoparticle-conjugated peptide targeting TfR (MF targeting TfR). Both in vitro and in vivo imaging demonstrated that, in the absence of miR9 during pre-differentiation of P19 cells, the MF targeting TfR nanoparticles greatly targeted TfR and were successfully internalized into P19 cells, resulting in high fluorescence and low MR signals.

Molecular imaging of a cancer-targeting theragnostics probe using a nucleolin aptamer- and microRNA-221 molecular beacon-conjugated nanoparticle.

MicroRNAs (miRNA, miR) have been reported as cancer biomarkers that regulate tumor suppressor genes. Hence, simultaneous detecting and inhibiting of miRNA function will be useful as a cancer theragnostics probe to minimize side effects and invasiveness. In this study, we developed a cancer-targeting therangostics probe in a single system using an AS1411 aptamer - and miRNA-221 molecular beacon (miR-221 MB)-conjugated magnetic fluorescence (MF) nanoparticle (MFAS miR-221 MB) to simultaneously target to cancer tissue, image intracellularly expressed miRNA-221 and treat miRNA-221-involved carcinogenesis.