Synthesis and Characterization of Polyion Complex Micelle Loaded with Zinc(II) Phthalocyanine Bearing Poly(aryl benzyl ether) Dendrimer

3,5-Di-(4'-cyanobenzyloxy)benzyl alcohol (1) was synthesized by reaction of 3,5-di-hydroxybenzyl alcohol with 4-cyanobenzyl bromide. 4-(3',5'-hydroxybenzyloxy)phthalonitrile (3) was obtained by reacation of 1 with 4-nitrophthalonitrile in DMF. Tetra-[3,5-di-(4'-cyanobenzyloxy)benzyloxy] zinc(II) phthalocyanine (4) was obtained by condensation of 3 in the presence of n-pentanol, acetate zinc(II) and DBU. The corresponding hydrophilic complexes tetra-[3,5-di-(4'-carboxylicbenzyloxy)benzyloxy] zinc phthalocyanine (5) was obtained by hydrolyzation of 4 in NaOH. The structures of above compounds were characterized by elemental analysis, IR, H-1 NMR, ESI-MS, MALDI-TOF-MS, and UV/Vis. A polyion complex micelle system 5/m, which was formed via an electronic interaction of anionic dendrimer phthalocyanine 5 and positively poly(L-lysine) segment of poly(ethylene glycol)-poly(L-lysine) block copolymer (PEG-b-PLL). The morphology and photophysical properties of 5/m was investigated by AFM, TEM, UV/Vis and fluorescence spectroscopy methods. The 5/m formed a core-shell-type nanoparticle with diameter ca.100 nm. Electrostatic assembly of 5/m resulted in a red-shift and higher intensity of the Q band, fluorescence intensity and singlet excited life compared with free 5. The time-dependence uptake amount of 5 and 5/m in HUVEC (human umbilical vein endothelial cell) cells showed that the uptake amount of 5/m was significantly increased and reached peak value by ahead of 1 h compared with 5. The in vitro photodynamic therapy efficiency of 5 and 5/m were evaluated by MTT method, and the results indicated that the photodynamic therapy efficacy of 5/m was enhanced when the polymeric nanoparticles was loaded with dendritic phthalocyanine 5.