Pharmaceutical Research

, Volume 25, Issue 9, pp 2002–2011

Contrast-Enhanced MRI-Guided Photodynamic Cancer Therapy with a Pegylated Bifunctional Polymer Conjugate


  • Anagha Vaidya
    • Department of Pharmaceutics and Pharmaceutical ChemistryUniversity of Utah
  • Yongen Sun
    • Department of Pharmaceutics and Pharmaceutical ChemistryUniversity of Utah
  • Yi Feng
    • Department of Pharmaceutics and Pharmaceutical ChemistryUniversity of Utah
  • Lyska Emerson
    • Department of PathologyUniversity of Utah
  • Eun-Kee Jeong
    • Department of RadiologyUniversity of Utah
    • Department of Pharmaceutics and Pharmaceutical ChemistryUniversity of Utah
    • 421 Wakara Way
Research Paper

DOI: 10.1007/s11095-008-9608-1

Cite this article as:
Vaidya, A., Sun, Y., Feng, Y. et al. Pharm Res (2008) 25: 2002. doi:10.1007/s11095-008-9608-1



To study contrast-enhanced MRI guided photodynamic therapy with a pegylated bifunctional polymer conjugate containing an MRI contrast agent and a photosensitizer for minimally invasive image-guided cancer treatment.


Pegylated and non-pegylated poly-(l-glutamic acid) conjugates containing mesochlorin e6, a photosensitizer, and Gd(III)-DO3A, an MRI contrast agent, were synthesized. The effect of pegylation on the biodistribution and tumor targeting was non-invasively visualized in mice bearing MDA-MB-231 tumor xenografts with MRI. MRI-guided photodynamic therapy was carried out in the tumor bearing mice. Tumor response to photodynamic therapy was evaluated by dynamic contrast enhanced MRI and histological analysis.


The pegylated conjugate had longer blood circulation, lower liver uptake and higher tumor accumulation than the non-pegylated conjugate as shown by MRI. Site-directed laser irradiation of tumors resulted in higher therapeutic efficacy for the pegylated conjugate than the non-pegylated conjugate. Moreover, animals treated with photodynamic therapy showed reduced vascular permeability on DCE-MRI and decreased microvessel density in histological analysis.


Pegylation of the polymer bifunctional conjugates reduced non-specific liver uptake and increased tumor uptake, resulting in significant tumor contrast enhancement and high therapeutic efficacy. The pegylated poly(l-glutamic acid) bifunctional conjugate is promising for contrast enhanced MRI guided photodynamic therapy in cancer treatment.


dynamic contrast enhanced MRIimage-guided cancer therapynon-invasive pharmacokineticsphotodynamic therapypolymer conjugates

Copyright information

© Springer Science+Business Media, LLC 2008