The Design, Preparation And Biological Application Of The Optical Functional Polymeric Nanoparticles

Since 1990 s, the use of nanomaterials of different natures and for various applications(multiple disciplines) has been greatly expanded, in particular over the last couple of decades. In particular polymeric nanoparticles, which have good biocompatibility, big loading content and facile surface functionalization have a wide range of applications in biomedicines, photochemical sensing, nanoparticle catalysis and other fields. In this thesis,the amphiphilic polymer m PEG-PLA is chosen to coate hydrophobic organic molecules used in biological imaging, therapy and photochemical sensing. The main contents are summarized as follows:(1) The water-soluble Cy Cl@m PEG-PLA nanoparticles using amphiphilic polymer m PEG-PLA as carrier, with near infrared hydrophobic dyes Cy Cl through self-assembly method were successfully synthetized. Cy Cl@m PEG-PLA nanoparticles, which combine near infrared dye Cy Cl with strong absorption in near infrared region, ability of genarating heat and converting normal tissue oxygen(3O2) to the very reactive and cytotoxic singlet oxygen(1O2) exposured by 785 nm wavelength light and amphiphilic polymer nanoparticles with good water solubility were applied in vitro photoacoustic imaging, photothermal therapy and photodynamic therapy. Introduction of amphiphilic polymer nanoparticles improved the water solubility and photostability of Cy Cl and solved limitation of Cy Cl in biological applications. In aqueous solution and cancer cells, photoacoustic effect, photothermal effect and photodynamic effect of Cy Cl@m PEG-PLA nanoparticles were proved, which suggsets that Cy Cl@m PEG-PLA nanoparticles have potential in photoacoustic imaging, photothermal therapy and photodynamic therapy in vivo.(2) Through self-assembly method, amphiphilic polymer m PEG-PLA and thermal activated delay fluorescent material 4Cz PN were converted to water-soluble temperature-responsive 4Cz PN@m PEG-PLA nanoparticles. It has good monodispersity, uniform particle size distribution, good water solubility, good photostability and big loading content. Introduction of amphiphilic polymer nanoparticles prevents oxygen to quench the fluorescent intensity of 4Cz PN and avoids cross-sensitivity to oxygen of 4Cz PN@m PEG-PLA nanoparticles. 4Cz PN@m PEG-PLA nanoparticles respond linearly and reversibly to temperature. Then, the temperature sensing mechanism of 4Cz PN@m PEG-PLA nanoparticles was guessed.