Synthesis And Property Of Polyfluorene Containing TEMPO Nano-polymer For Dual-modal Imaging&Cu-Sb-S Nanoparticles For Photoacoustic Imaging And Photothermal Therapy

Part1 Synthesis and property of polyfluorene containing TEMPO nano-polymer for dual-modal imagingObjectivesEarly diagnosis of cancer play a critical role in the prognosis of disease.At present,the existing imaging methods have their own limitations,so it is difficult to achieve early diagnosis of cancer.The purpose of this study is to synthesize a water-soluble polyfluorene containing 2,2,6,6-Tetramethylpiperidinel-Oxyl(TEMPO)polymer for optical and MR bimodal imaging,and then assess its in vitro/vivo imaging properties in order to use it as the preparation of a dual-modal probes for targeted in vivo fluorescence and magnetic resonance imaging.Methods1 TEMPO monomer was modified in polyfluorene side chains used the Suzki Coupling reaction,and then charged moieties was modified on another side chains.1H NMR,FTIR,DLS,TEM,UV-vis and so on were used to evaluate the properties of TEMPO-PPF.2 The in vitro evaluation methods include MTT cytotoxicity assay,fluorescence imaging,photostability test,flow cytometry,cellular MR imaging;In vivo evaluation methods include acute toxicology experiment,intratumoral MR and optical imaging.Results1 TEM micrographs showed the average size of TEMPO-PPF polymer was about 30nm,and the hydrodynamic diameters was about 54nm.UV-vis appeared strong fluorescence emission peak at 420nm,and blue fluorescence was displayed under 365nm UV excitation.The relaxivity was about 0.28mM/s.2 No significant toxicity in cell viability was observed up to 5.68mmol/L concentration in A549 cells.After incubated with TEMPO-PPF,the fluorescence was obviously accumulated in the cytoplasm of A549 cells,and which was also showed well photostability.In cellular MR imaging examination,the MR signal of TEMPO-PPF group was statistically significant higher than that of the blank group.3 In the acute toxicity experiment of nude mice for 1 weeks,TEMPO-PPF polymers exhibit good biocompatibility,and fluorescence/MR imaging also showed statistically difference after intratumor injection.ConclusionsThe water-soluble polymer TEMPO-PPF has relatively good biocompatibility,and can be used for bimodal optical and MR imaging in vitro and in vivo.This results suggested that it can be used as a dual-modal probes for targeted in vivo fluorescence and magnetic resonance imaging.Part 2 Evaluation of Cu-Sb-S nanoparticles for photoacoustic imaging and photothermal therapyObjectivesIt is important to accurate detection of early lesion and monitor the therapeutic effect after therapy,but if the imaging reagents and drug or treatment are integrated,it will be improve the therapeutic effect and reduce the side effects on normal tissue while the imaging probe convey to the lesion,which can achieve theranostics even to personalized treatment.The aim of this study was to synthesize a Cu-Sb-S photoacoustic/photothermal therapeutic probe,and to evaluate its in vitro photoacoustic imaging and photothermal therapy of HELA cells.Methods2.1 The hot injection method was used to synthesize Cu-Sb-S nanoparticles,and by modifying the different reaction conditions to find the optimum reaction conditions of pure and good morphology Cu-Sb-S nanocrystals.And then used PVP to modify Cu-Sb-S as a hydrophilic nanoparticles.TEM and XRD was used to evaluate its properties and the absorption of PVP-Cu-Sb-S nanoparticles in 808nm was measured by UV-vis.Finally,the photoacoustic imaging and photothermal effects was also be assessed.2.2 The in vitro cytotoxicity of PVP-Cu-Sb-S nanoparticles was evaluated using CCK-8 assay,and Living Dead Cell Staining and CCK-8 assay and flow cytometry were used to assess the photothermal therapy of HELA cells.Results2.1 The particle size of Cu-Sb-S nanoparticles was about 20.88nm,and its XRD pattern matched the orthorhombic Cui2Sb4S13.UV-vis also showed that the optical absorption intensity of PVP-Cu-Sb-S nanoparticles in 808nm is about 0.68a.u under the concentration of 0.2mg/mL.In addition,different concentrations of PVP-Cu-Sb-S nanoparticles showed good photoacoustic imaging and photothermal effect in 808nm.2.2 Up to 0.4mg/mL concentration,there was no significant toxicity in cell viability was observed in HELA cells.In the Living Dead Cell Staining,the group that incubated with PVP-Cu-Sb-S nanoparticles and laser treatment at the same time showed significant different when compared with the other groups(PVP-Cu-Sb-S group;Pure culture medium + laser treatment group;Pure culture medium group),the CCK-8 assay and flow cytometry results also showed statistically significant different.ConclusionsThe preparation of PVP-Cu-Sb-S nanoparticles has good biocompatibility,and also shows good photothermal therapy and photoacoustic imaging in vitro.This results suggested that it can be used as an efficient targeted agent for photoacoustic imaging and photothermal therapy.