Photophysics and ex vivo biodistribution of β-cyclodextrin-meso-tetra(m-hydroxyphenyl)porphyrin conjugate for biomedical applications

Photochem Photobiol Sci. 2014 Aug;13(8):1185-91. doi: 10.1039/c4pp00088a.

Abstract

Low aqueous solubility of porphyrin-based photosensitizers hampers their clinical use in photodynamic therapy because of complex delivery. In this study, we explore meso-tetra(m-hydroxyphenyl)-21,23H-porphyrin (mTHPP), a potent photosensitizer, covalently attached to β-cyclodextrin (CD-mTHPP) with a focus on topical delivery and cellular uptake. The photophysical properties of CD-mTHPP were examined using steady-state fluorescence and lifetime measurements verifying increased aqueous solubility. Confocal and fluorescence lifetime imaging microscopy on human squamous carcinoma cells (A431) evidenced a cytoplasmic uptake of CD-mTHPP in predominantly monomeric form. CD-mTHPP was also delivered to human skin ex vivo and the skin penetration was assessed using two-photon fluorescence microscopy. The results indicated that CD-mTHPP exhibits improved skin distribution compared to mTHPP alone using aqueous vehicles. Thus the CD-mTHPP conjugate demonstrates improved biodistribution ex vivo compared to mTHPP and is a promising multimodal system for photodynamic therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport, Active
  • Carcinoma, Squamous Cell / metabolism
  • Cell Line, Tumor
  • Female
  • Humans
  • In Vitro Techniques
  • Microscopy, Fluorescence, Multiphoton
  • Photochemical Processes
  • Photochemotherapy
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / pharmacokinetics*
  • Porphyrins / chemistry*
  • Porphyrins / pharmacokinetics*
  • Skin / metabolism
  • Solubility
  • Spectrometry, Fluorescence
  • Spectrophotometry
  • Water
  • beta-Cyclodextrins / chemistry*
  • beta-Cyclodextrins / pharmacokinetics*

Substances

  • Photosensitizing Agents
  • Porphyrins
  • beta-Cyclodextrins
  • tetra(3-hydroxyphenyl)porphine
  • Water