Preparation Of Functional Magnetic Nanoparticles And Their Applications In Magnetic Targeting And Cancer Theranostic

Magnetic nanoparticles have broad applications in medical imaging, magnetictargeted anti-cancer drug delivery and tumor therapy because of their unique magneticproperties. In this work, iron oxide nanoclusters (IONCs) are synthesized throughsolvent thermal method. Based on surface modification and functionalization, wemainly study their applications in cancer magnetic targeting, imaging and therapy.In the first work, IONCs are modified by a drafted co-polymer, DA-PAA-PEG.Photosensitizer, Chlorin e6(Ce6), is successfully loaded onto the surface of IONC-PEGby chelation, forming IONC-PEG-Ce6. Because of its unique water solubility,IONC-PEG-Ce6can specifically target and accumulate in tumor site. The magneticproperties of IONCs and optical properties of Ce6are used for in vivo magneticresonance imaging and fluorescent imaging respectively. Benefiting from the red-shiftof Ce6, the genetrating singlet oxygen can efficiently inhibit the growth of tumor underthe excitation of near-infrared light.In the second work, we fabricate a core/shell structured magnetic-plasmonic nanotheranostic agent, IONC@Au-PEG. The PEG modified IONC@Au is very stable inaqueneous and physiological solution. Magnetic targeting can greatly enhance theenrichment of nanoagent in targeted tumor. While magnetic resonance imaging isemployed for tumor localization, photoacoustic imaging with high resolution is used toprecisely delineate tumor. Based on the dual-modal imaging, photothermal therapy cancompletely cure targeted tumor. With the assistance of infrared thermal maging, we canprecisely monitor the temperature during therapy. Most importantly, regrowth is not observed based on the post-treatment magnetic resonance imaging. Consequently, wesuccessfully achieve the magnetic targeting enhanced theranostic strategy relying onIONC@Au-PEG.Based on the as-made magnetic functional nanomaterials, we achieve highlyefficient in vivo magnetic targeting, multi-modal imaging and tumor therapy. Theresults are of great value to exploit new application of magnetic nanomaterials innanomedicine. And, the biocompatible anti-cancer drug delivery system, the magnetictargeting enhanced theranostic strategies have great potential in clinic and broadapplication prospect.