论文部分内容阅读
Background: In recent years, near-infrared fluorescence (NIRF)-labeled iron nanoparticles have been synthesizedand applied in a number of applications, including the labeling of human cells for monitoring the engraftmentprocess, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing theirin vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probefor cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores.However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imagingaround 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additionalalternative NIRF-labeled iron nanoparticles for application in this area.Results: This study manufactured 12-nm DMSA-coated Fe3O4 nanoparticles labeled with a near-infraredfluorophore, IRDye800CW (excitation/emission, 774/789 nm), to investigate their applicability in cell labeling and invivo imaging. The mouse macrophage RAW264.7 was labeled with IRDye800CW-labeled Fe3O4 nanoparticles atconcentrations of 20, 30, 40, 50, 60, 80 and 100 μg/ml for 24 h. The results revealed that the cells were efficientlylabeled by the nanoparticles, without any significant effect on cell viability. The nanoparticles were injected intothe mouse via the tail vein, at dosages of 2 or 5 mg/kg body weight, and the mouse was discontinuously imagedfor 24 h. The results demonstrated that the nanoparticles gradually accumulated in liver and kidney regionsfollowing injection, reaching maximum concentrations at 6 h post-injection, following which they were graduallyremoved from these regions. After tracing the nanoparticles throughout the body it was revealed that they mainlydistributed in three organs, the liver, spleen and kidney. Real-time live-body imaging effectively reported thedynamic process of the biodistribution and clearance of the nanoparticles in vivo.Conclusion: IRDye800CW-labeled Fe3O4 nanoparticles provide an effective probe for cell-labeling and in vivoimaging.