Synthesis Of Phosphorescent Metal Iridium Polymer Nanoparticles And Its Application In Optical Imaging, Nuclear Magnetic Imaging And Photodynamic Therapy

Iridium complexes, which exhibit long lifetime of phosphorescence, excellent photo-stability, large stokes and easy adjustment of emission wavelength, have attracted much attention in the field of phosphorescent light-emitting diodes, photocatalysis and chemical sensor. However, the poor water solubility and biocompatibility of Ir（III） complexes in biological media limits their widely application in the living system. In this present paper, we have adopted two kinds of simple and feasible methods to prepare two kinds of coordination polymer nanoparticles. These nanoparticles solve the problem effectively and expend the application of Ir（III） complexes in bioimaging and photodynamic therapy. The specific research content as follows: 1. Phosphorescent polymeric nanoparticles by coordination cross-Linking as a platform for luminescence imaging and photodynamic therapyIn this part, we have synthesized three phosphorescent polymeric nanoparticles by coordination cross-linking poly（4-vinyl pyridine-b-ethylene oxide）（P4VP-b-PEO） with three different kinds of iridium chloride-bridged dimers, respectively. These nanoparticles we have parepared, present uniform morpholoy, good water solubility,biocompatibility and multicolor phosphorescence. The experimental results on MTT assay and flow cytometry revealed polymeric nanoparticles have low toxicity and could be uptaken by He La cells efffectively. The experiment of laser confocal fluorescence microscopy illustrates that the nanopaticles can be used as phosphorescent biomarkers for living cells. In order to disscuss the effiency of producing singlet oxygen, the nanoparticles were first detected in solution. Trypan blue staining and MTT assay in He La cells also indicated the possibility for photodynamic therapy of polymeric nanoparticles. 2. Phosphorescent coordination polymer nanoparticles as a three-in-One platform for optical imaging, T₁?weighted magnetic resonance imaging, and photodynamic therapyIn this part, we have prepared Ir-Gd coordination polymer nanoparticles by coordination assembly of carboxy-functionalized Ir（III） complexes（[（pq）2Ir（Hdcbpy）]）with magnetic Gd（III） ions in the presence of polyvinylpyrrolidone（PVP）.We can draw a conclusion from the experiments of SEM,TEM and stability detection in different solutions that nanoparticles were uniform, stability. The MRI experiments in solution and He La cells all present great T₁-positive contrast effect. We have also investigated the bioimaging effect of Ir-Gd coordination polymer nanoparticles through laser scanning confocal microscopy in detail. The generation of singlet oxygen were detected in solution and trypan blue staining and a standard MTT assay were used to evaluate the efficacy of nanoparticles to eliminate cancer cells. All those results suggest that Ir-Gd nanoparticles have great prospect for photodynamic therapy.