A phthalocyanine-peptide conjugate with high in vitro photodynamic activity and enhanced in vivo tumor-retention property

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Mei-Rong Ke
  • Sin-Lui Yeung
  • Wing-Ping Fong
  • Dennis K. P. Ng
  • Pui-Chi Lo

Detail(s)

Original languageEnglish
Pages (from-to)4225-4233
Journal / PublicationChemistry - A European Journal
Volume18
Issue number14
Publication statusPublished - 2 Apr 2012
Externally publishedYes

Abstract

A novel zinc(II) phthalocyanine conjugated with a short peptide with a nuclear localization sequence, Gly-Gly-Pro-Lys-Lys-Lys-Arg-Lys-Val, was synthesized by click chemistry and a standard Fmoc solid-phase peptide synthesis protocol. The conjugate was purified by HPLC and characterized with UV/Vis and high-resolution mass spectroscopic methods. Both this compound and its non-peptide-conjugated analogue are essentially non-aggregated in N,N-dimethylformamide and can generate singlet oxygen effectively with quantum yields (ψ δ) of 0.84 and 0.81, respectively, relative to unsubstituted zinc(II) phthalocyanine (ψ δ=0.56). Conjugation of the peptide sequence, however, can enhance the cellular uptake, efficiency in generating intracellular reactive oxygen species, and photocytotoxicity of the phthalocyanine-based photosensitizer against HT29 human colorectal carcinoma cells. The IC 50 value of the conjugate is as low as 0.21 μM. In addition, the conjugate shows an enhanced tumor-retention property in tumor-bearing nude mice. After 72 h post-injection, the dye concentration in the tumor was significantly higher than that in other organs. The results suggest that this phthalocyanine-peptide conjugate is a highly promising photosensitizer for photodynamic therapy. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research Area(s)

  • peptides, photodynamic therapy, photosensitizers, phthalocyanines, singlet oxygen

Citation Format(s)

A phthalocyanine-peptide conjugate with high in vitro photodynamic activity and enhanced in vivo tumor-retention property. / Ke, Mei-Rong; Yeung, Sin-Lui; Fong, Wing-Ping; Ng, Dennis K. P.; Lo, Pui-Chi.

In: Chemistry - A European Journal, Vol. 18, No. 14, 02.04.2012, p. 4225-4233.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review