Controlled Drug Delivery And Photo-dynamics Therapy Based On Multifunctional Core-shell-shell Nanoparticles

Traditional Cancer therapeutics is full of drawbacks, cause of bad therapeutic effect, long treatment period, expensive and highly risk. There’re some new innovated method of cancer therapy like targeted nanoparticle drug delivery technology. Next generation theranostic devices will rely on the smart integration of different functional moieties into one system, functions like drug delivery, stimulated drug release, specific targeting, biological imaging, in vivo diagnosis and photodynamic therapy. This thesis introduces to the design and synthesis of a multifunctional NPs, which containing p H-stimuli drug delivery, PDT, specific targeting and biological imaging,mainly researching on p H-stimuli drug delivery and PDT, which helps to a cocktail cancer therapy.For the aspect of preparation, in this thesis, a core-shell-shell structure MSNPs UCNP@SiO₂（MB）@m SiO₂ is prepared of thermal decomposition method and sol-gel method. The Ln³⁺ doped uponconversion nanoparticles UCNP@SiO₂（MB）@m SiO₂ is response to 980 nm NIR light, its emission spectrum in 660 nm is highly matched with the UV-Vis absorption spectrum of MB, thus singlet oxygen is generated by this procedure; the other emission light of UCNP in 540 nm can be used for biological imaging. The core-shell-shell MSNP is a good vehicle for loading anti-cancer drug DOX, cause the abundant mesoporous. PEI-FA is also prepared for encapsulating the drug loaded core-shell-shell MSNP by electrostatic reaction. The drug loading amount of core-shell-shell MSNP/PEI-FA was enhanced by surface modification. In the aspect of functionality, just the function of p H-stimuli drug delivery and PDT is researched and estimated. The drug loading amount enhancement is the result of comparing the modified MSNP and the unmodified one. Furtherly more experiments are used to clarify the p H-stimuli drug release result under different proportion of PEI-FA and series p H values. The DPBF molecule is a singlet oxygen probe, testing the UV-Vis absorption spectrum of DPBF is used to detect the amount of singlet oxygen. Finally the properties and the promising application in bio-medical background can be comprehensively assessed.