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A pH‐Responsive Layered Double Hydroxide (LDH)–Phthalocyanine Nanohybrid for Efficient Photodynamic Therapy
Author(s) -
Li XingShu,
Ke MeiRong,
Huang Wei,
Ye ChunHong,
Huang JianDong
Publication year - 2015
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201404514
Subject(s) - hydroxide , singlet oxygen , phthalocyanine , layered double hydroxides , chemistry , cationic polymerization , aqueous solution , photodynamic therapy , aqueous medium , neutral red , absorption (acoustics) , zinc , oxygen , photochemistry , materials science , inorganic chemistry , cytotoxicity , polymer chemistry , organic chemistry , in vitro , biochemistry , composite material
Abstract A pH‐responsive nanohybrid (LDH–ZnPcPS 4 ), in which a highly hydrophilic zinc(II) phthalocyanine tetra‐α‐substituted with 4‐sulfonatophenoxy groups (ZnPcPS 4 ) is incorporated with a cationic layered double hydroxide (LDH) based on electrostatic interaction, has been specially designed and prepared through a facile co‐precipitation approach. ZnPcPS 4 is an excellent singlet‐oxygen generator with strong absorption at the near‐infrared region (692 nm) in cellular culture media, whereas the photoactivities of ZnPcPS 4 were remarkably inhibited after incorporation with the LDH. The nanohybrid is essentially stable in aqueous media at pH 7.4; nevertheless, in slightly acidic media of pH 6.5 or 5.0, ZnPcPS 4 can be efficiently released from the LDH matrix, thus leading to restoration of the photoactivities. The nanohybrid shows a high photocytotoxicity against HepG2 cells as a result of much more efficient cellular uptake and preferential accumulation in lysosomes, whereby the acidic environment leads to the release of ZnPcPS 4 . The IC 50 value of LDH–ZnPcPS 4 is as low as 0.053 μ M , which is 24‐fold lower than that of ZnPcPS 4 . This work provides a facile approach for the fabrication of photosensitizers with high photocytotoxicity, potential tumor selectivity, and rapid clearance character.