Polymeric Nanoparticles Encapsulated Silicon (Ⅳ) Phthalocyanines Bearing Fluorinated Aryl Benzyl Ether Dendritic Substitutions:Synthesis And Their Interaction With DNA

In this paper, two series of silicon (Ⅳ) phthalocyanines bearing fluorinated and non-fluorinated aryl benzyl ether dendritic substitutions with different terminal functionalities (cyano, nitro and ester) had been synthesized. They were di-(2-4-hydroxyphenyl-2-4-cyanobenzyl fluorinated propyl) silicon (Ⅳ) phthalocyanine (SiPc-F-CN), di-(2-4-hydroxyphenyl-2-4-nitrobenzyl fluorinated propyl) silicon (Ⅳ) phthalocyanine (SiPc-F-NO2) and di-(2-4-hydroxyphenyl-2-4-methoxycarbonyl fluorinated propyl) silicon (Ⅳ)phthalocyanine (SiPc-F-COOCH3))5di-(2-4-hydroxyphenyl-2-4-cyanobenzyl propyl) silicon (Ⅳ) phthalocyanine (SiPc-CN), and di-(2-4-hydroxyphenyl-2-4-nitrobenzyl propyl)silicon (Ⅳ) phthalocyanine (SiPc-NO2)). The structures of two series of dendritic silicon (Ⅳ) phthalocyanines were characterized by elemental analysis, IR,1H NMR, ESI-MS, and MALDI-TOF-MS methods.The photophysical properties of silicon (Ⅳ) phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions were studied by UV/Vis and fluorescence spectroscopic methods. These phthalocyanines were dissoluble in organic solvents such as dimethyl formamide (DMF), methylene chloride, acetone, tetrahydrofuran. They exhibited a strong Q band at681nm. The shape and position of Q band does not change with the phthalocyanine concentration. These results indicated that two series of silicon phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions mainly existed as a monomer in DMF. Due to the existence of fluorinated substituent (CF3), the fluorescence properties of silicon phthalocyanines bearing fluorinated dendritic substitutions were greatly photosensitized.The maximum fluorescence emission of silicon phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions were at690nm. Fluorescence intensity of silicon phthalocyanines bearing fluorinated dendritic substitutions were stronger than that of silicon phthalocyanines bearing non-fluorinated dendritic substitutions. The terminal functionalities nature also exerted influence on the fluorescence intensity of silicon phthalocyanines bearing fluorinated dendritic substitutions. The fluorescence intensity follow the order, SiPc-F-CN>SiPc-F-COOCH3 > SiPc-F-NO2. The singlet state lifetimes of silicon phthalocyanines bearing fluorinated dendritic substitutions were significantly longer than that of silicon phthalocyanines bearing non-fluorinated dendritic substitutions.Photoinduced intermolecular electron transfer between silicon phthalocyanines with fluorinated and non-fluorinated dendritic substitutions and benzoquinones had been investigated by UV/Vis and steady state fluorescence spectroscopic methods. Upon excitation, the Q band of silicon phthalocyanines with fluorinated and non-fluorinated dendritic substitutions did not change, while the maximum emission of phthalocyanines were gradually quenched with increasing the concentration of benzoquinones. It was proposed that the electron was transferred from the dendritic phthalocyanine donor to benzoquinone acceptors.The intramolecular energy transfer of silicon phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions was studied by steady state fluorescence spectroscopic methods. Upon excitation, energy were transferred from the dendron to the phthalcyanine core. Terminal functionalities nature exerted influence on the energy transfer efficiency. With the same dendron strcture, the nature of terminal functionalities effect the energy transfer efficiency follow the order:SiPc-F-NO2> SiPc-F-CN> SiPc-F-COOCH3. The energy transfer efficiency of silicon phthalocyanines bearing fluorinated dendritic substitutions were higher than that with non-fluorinated dendritic substitutions. This maybe due to the existence of fluorinated substituent (CF3), molecules configuation become rigidity.The amphiphilic diblock copolymer polyethylene glycol monomethyl ether-polycaprolactone (MPEG-PCL) was selected as drug carriers. Four amphiphilic diblock copolymers with different hydrophilic/hydrophobic proportion were chosed to load silicon phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions, respectively. The polymeric nanoparticles loaded with dendritic phthalocyanines were prepared using water/DMF as cosolvent. The morphology and particle size distribution of polymeric nanoparticles loaded with silicon (Ⅳ) phthalocyanines with fluorinated and non-fluorinated dendritic substitutions were studied by TEM and laser nanometer particle size analyzer. They were sphere and the diameter in solution were in the range between 109-246nm. The photophysical properties of nanoparticles loaded with dendritic phthalocyanines were studied by UV/Vis and fluorescence spectroscopic methods. The nanoparticles loaded with dendritic phthalocyanines showed lower intensity in the UV/Vis absorption and fluorescence emission. The nanoparticles using both amphiphilic block copolymer MPEG-PCL-1and MPEG-PCL-2as carriers exhibited the highest drug laod capacity and fluorescence intensity as well as longest lifetimes. Therefore, MPEG-PCL-1and MPEG-PCL-2were regarded as excellenr drug carriers.The singlet oxygen generation rate, the formation rate constants and quantum yield of with fluorinated and non-fluorinated dendritic substitutions were determined. The nature of terminal groups effected on the singlet oxygen generation rate,the formation rate constants, and quantum yieldwere studied. The singlet oxygen generation rate, the formation rate constants, and quantum yield follow the order:SiPc-F-CN> SiPc-F-COOCH3>SiPc-F-NO2. The singlet oxygen generation rate and the formation rate constants, and quantum yield of silicon phthalocyanines with fluorinated dendritic substitutions were higher than that of silicon (IV) phthalocyanines bearing non-fluorinated dendritic substitutions. As the fluorescence intensity of polymeric nanoparticles decreased, the intersystem crossing of polymeric nanoparticles increased, the singlet oxygen generation rate and the formation rate constants of polymeric nanoparticle were higher than that of corresponding free phthalocyanine. Therefore, polymeric nanoparticles loaded with silicon phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions were excellent the third generation photosensitizer.The interaction between the polymeric nanoparticles loaded with silicon (IV) phthalocyanines bearing fluorinated and non-fluorinated dendritic substitutions with CT-DNA were investigated by UV/Vis and fluorescence spectroscopic method. Due to the existence of fluorinated substituent (CF3), polymeric nanoparticles loaded with silicon (IV) phthalocyanines bearing fluorinated dendritic substitutions exhibited efficient DNA-binding activity. The polymeric nanoparticles SiPc-F-COOCH3exhibited the best activity based on its highest binding constant. In addition, the binding position of polymeric nanoparticles loaded with dendritic silicon phthalocyanines with CT-DNA were investigated by competitive titration method using ethidium bromide (EB) or sodium chloride (NaCl) as competitive agents. The polymeric nanoparticles loaded with fluorinated dendritic silicon phthalocyanines binded with DNA on the phosphoric acid position. The photodegradation DNA plasmid of polymeric nanoparticles loaded with with fluorinated dendritic silicon phthalocyanines were studied by electrophoresis method. The SiPc-F-CN exhibited best photodegradation ability. The polymeric nanoparticles SiPc-F-CN exhibited best activity than other ones.