Synthesis And Preparation Of Magnetic Fluorescent Hybrid Micelles And Their Application Of Biological Imaging

Magnetic fluorescent polymer materials are a kind of combing the magnetic properties of magnetic nanoparticles and unique optical properties of fluorescent materials, which exhibit excellent applications in biomedical separation and biomedical engineering including multimode optical/magnetic resonance imaging, cell marking and cell separation, enzyme immobilization, tumor target therapy, and so on. The work presented here focus on preparing magnetic fluorescent hybrid micelles by self-assembly of amphiphilic copolymers and magnetic nanoparticles, The morphology, size, chemical composition and structure, cytotoxicity, magnetic and fluorescent properties of the synthesized nanocomposites are characterized. Their potential application as multimodal optical/MRI imaging probes and in vivo distribution in the SD rats are also studied. The details are as follows:The F3O4-encapsulated polymeric micelles composed of cores containing magnetic nanoparticles and polyethylene glycol (PEG) shells are synthesized by self-assembly of amphiphilic poly (HFMA-co-VBK)-g-PEG copolymers and oleic acid stabilized Fe3O4nanoparticles. The Fe3O4magnetic nanoparticles in the core produce T2-weighted MR imaging functionalities, whereas the small fluorescent monomer carbazole in the polymer shell introduces good fluorescent properties. The multifunctional micelles exhibit excellent paramagnetic properties with the maximum saturation magnetization of9.61emu/g and transverse relaxivity rate of157.44mM-1S-1. In vivo magnetic resonance imaging (MRI) studies reveal enhanced contrast between the liver and spleen. Fluorescence spectra show characteristic emission peaks from carbazole at350nm and365nm and vivid blue fluorescence can be observed by2-photon confocal scanning laser microscopy (CLSM). In vivo optical imaging demonstrates the unique fluorescent characteristics of the Fe3O4-encapsulated polymeric micelles in the liver and spleen and the excellent multifunctional properties suggest potential clinical use as nanocarriers in magnetic resonance imaging and optical imaging.New water-soluble magnetic and luminescent hybrid micelles are synthesized by self-assembly of amphiphilic poly (HFMA-co-Eu(AA)3Phen)-g-PEG copolymers and oleic acid modified Fe3O4nanoparticles, which show a spherical morphology, paramagnetic properties with a maximum saturation magnetization of7.05emu/g, and a high transverse relaxivity of340mM-1s-1. According to in vivo magnetic resonance imaging (MRI) experiments, excellent contrast of the liver and spleen was achieved after injection of the hybrid micelles. Fluorescence spectra show characteristic emission peaks from the rare earth Eu at616nm and vivid red fluorescence can be observed by2-photon confocal scanning laser microscopy (CLSM). In vivo optical imaging demonstrates the unique fluorescent characteristics of the magnetic and luminescent hybrid micelles in the liver and spleen and the excellent multifunctional properties suggest the possibility of clinical use as nanocarriers in magnetic resonance imaging and optical imaging.