Synthesis,Imaging And Tumor Therapy Effect Of Several Kinds Of Functional Nano-materials

In recent years,nanoparticles with the luminescence and magnetic property have gained much attention from researchers for using in multifunctional drug delivery systems,which provide anticancer drug,photo-thermal and photo-dynamic materials with in a single system.Among all the nanoparticles,lanthanide doped up-conversion nanoparticles(UCNPs)can emit visible light with the excitation of 808 nm NIR laser by designing the core-shell-shell structure.In this dissertation,metal oxide and core-shell rare earth up-conversion luminescence materials were synthesized by using high temperature thermal decomposition method.And the materials were modified and served as drug carriers,photo thermal agent and photo dynamic agent.The nanomaterials luminescence properties,biocompatibility,multimodality imaging,drug delivery,photo thermal therapy efficiency,photo dynamic therapy efficiency,multi modal therapy efficiency and multimodality imaging wereinvestigated in detail.The main contents can be summarized as follows:Monodisperse,regular-shaped and well-crystallized lanthanide-doped Na3ScF6 nanocrystals(NCs)with diverse shapes and structures are synthesized in high boiling organicsolvents of 1-octadecene and oleic acdd through a competitive nucleation and growth pathway.It is found that the Na3ScF6 doped with different Yb3+/Er3+,Yb3+/Tm3+ and Yb3+/Ho3+ emit multicolor visible photoluminescence upon 980 nm near-infrared light exciation.The color and the intensity of the UC emissions can also be tuned by altering the concentration of doped Yb3+.Compared with the pure Na3ScF6:Ln,the UC emission intensity can markedly be enhanced by introducing the core/shell structure.Based on the fact that the relative emission intensities of different emission colors can be precisely adjusted in a broad range by tuning the Yb3+ doping concentration,the as-obtained nanoparticles contribute themselves great potential applications in various fields.A facile solution-based thermal decomposition strategy,using very cheap polyisobutene succimide(PIBSI)and paraffin oil as surfactant and solvent,has been developed for the controllable synthesis of magnetic MnO,MnFe2O4 and CoFe2O4 nanocrystals(NCs)with high dispersibility,uniform shape,and high yield.And the textural,morphological and structural properties of the composites were carefully characterized by X-ray diffraction,N2 adsorption/desorption,transmission electron microscopy,scanning electron microscopy,photoluminescence spectra and superconducting quantum interference device,respectively.By fine-tuning reaction temperature and growth time,the morphology and size of MFe2O4 and MO NCs can be simply regulated.It is found that the surfactant PIBSI plays a key role in the final shape of the products due to its long chain with non-polar groups,which can markedly hinder the aggregation of the NCs and thus greatly improve the stability and dispersibility of the products.Taking MnFe2O4 NCs as example,it is found that the product has good biocompatibility and obvious T2 contrast enhancement effects have been achieved with the increase of iron concentration.MnFe2O4 NCs shows high longitudinal relaxivity of 165.6 mM-1 S-1 in aqueous solutions due to the positive signal enhancement ability of Fe3+ions,indicating the highly potential to be used as effective T2 contrast agent for magnetic resonance imaging(MRI).A novel multifunctional anti-cancer nanoplatform has been firstly developed by conjugating photo thermal agent(CuS nanoparticles)and cancer cell target agent(folic acid,FA)onto the surface of mesoporous silica coated core-shell-shell up-conversion nanoparticles(UCNPs).It was found that the doxorubicin(DOX)loaded system exhibits obviously pH and NIR-responsive release behaviour and the drug can be targetedly delivered into the cancer cells by receptor mediated endocytosis manner.Furthermore,both photothermal therapy(PTT)and chemotherapy can be triggered simultaneously by a single 808 nm near infrared(NIR)light,thus leading to a synergistic effect.The combined chemo-and NIR photothermal therapy can significantly improve the therapeutic efficacy superior to any single therapy,which has been evidenced by both in vitro and in vivo results.Besides,due to the doped rare earth ions,the platform also exhibits good up-conversion luminescence(UCL),computed tomography(CT)and magnetic resonance imaging(MRI)properties.Based on the excellent multimodal imaging and anti-tumor properties,the multifunctional nanoplatform should be a promising candidate for imaging-guided anti-cancer therapy.We have constructed a well-defined core-shell structured NaGdF4:Yb/Tm@NaGdF4:Yb@NaNdF4:Yb@NaGdF4@mSiO2@TiO2(UCNPs@mSiO2@ TiO2)nanocomposite by coating a layer of TiO2 PSs/photocatalyst on an effective 808 nm-to-UV/visible up-conversion luminescent(UCL)core to achieve simultaneous multiple bio-imaging and efficient PDT.The design of quenching-shield layer can eliminate the back energy transfer from activator Tm3+to sensitized Nd3+,thus significantly improving the UCL emission.The high surface area of mesoporous silica coated UCNPs facilitates the stable and high loading amount of anatase TiO2.In vivo results indicate that 808 nm NIR light mediated PDT using UCNPs@mSiO2@TiO2 as photosensitizers show much higher anti,tumor efficacy than those with 980 nm and UV irradiations due to the higher tissue penetration depth.Meanwhile,the platform itself as an imaging nanoprobe endows the sample with multiple imaging(UCL/CT/MRI)properties.Our work provide a new direction to further study diagnose and therapy of cancer induced by NIR light.We synthesized the mesoporous NaGdF4:Yb,Er,Mn,Co@SiO2-CuS-ZnPc nanoparticles with effective UCL host of NaGdF4:Yb,Er,Mn,Co as the core,mesoporous silica layer as the shell decorated with CuS and ZnPc which can be used as both multiple imaging(CT,T1 and T2MRI,UCL,photo-thermal)agent and drug carriers for antitumor(PTT,PDT,and chemo-).Moreover,photothermal therapy and photo dynamic therapy can be excited by 980 nm NIR laser to produce synergistic therapy efficiency.The synergy therapy efficiency:can overcome the shortcoming of the single therapy and confirmed by the experiment result in vivo and in vitro.In addition,the cancer therapy platform haves the UCL/CT/T1 and T2 MRI imaging efficiency due to the doping lanthanide rare earth element.Based on multi-modal imaging and anticancer properties,the multifunctional therapy platform can be a promising imaging guided anticancer therapy platform.