Next Article in Journal
Squalene Cyclases and Cycloartenol Synthases from Polystichum polyblepharum and Six Allied Ferns
Next Article in Special Issue
Use of Cyclodextrins in Anticancer Photodynamic Therapy Treatment
Previous Article in Journal
Search of Neuroprotective Polyphenols Using the “Overlay” Isolation Method
Previous Article in Special Issue
Effects of Blue-Light-Induced Free Radical Formation from Catechin Hydrate on the Inactivation of Acinetobacter baumannii, Including a Carbapenem-Resistant Strain
Article Menu
Issue 8 (August) cover image

Export Article

Open AccessFeature PaperArticle
Molecules 2018, 23(8), 1842; https://doi.org/10.3390/molecules23081842

Measurement of Cyanine Dye Photobleaching in Photosensitizer Cyanine Dye Conjugates Could Help in Optimizing Light Dosimetry for Improved Photodynamic Therapy of Cancer

1
PDT Center, Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
2
Department of Biomedical Engineering, Wright State University, Dayton, OH 45435, USA
*
Author to whom correspondence should be addressed.
Received: 24 May 2018 / Revised: 2 July 2018 / Accepted: 13 July 2018 / Published: 24 July 2018
(This article belongs to the Special Issue Advances in Photodynamic Therapy 2018)
Full-Text   |   PDF [3077 KB, uploaded 24 July 2018]   |  

Abstract

Photodynamic therapy (PDT) of cancer is dependent on three primary components: photosensitizer (PS), light and oxygen. Because these components are interdependent and vary during the dynamic process of PDT, assessing PDT efficacy may not be trivial. Therefore, it has become necessary to develop pre-treatment planning, on-line monitoring and dosimetry strategies during PDT, which become more critical for two or more chromophore systems, for example, PS-CD (Photosensitizer-Cyanine dye) conjugates developed in our laboratory for fluorescence-imaging and PDT of cancer. In this study, we observed a significant impact of variable light dosimetry; (i) high light fluence and fluence rate (light dose: 135 J/cm2, fluence rate: 75 mW/cm2) and (ii) low light fluence and fluence rate (128 J/cm2 and 14 mW/cm2 and 128 J/cm2 and 7 mW/cm2) in photobleaching of the individual chromophores of PS-CD conjugates and their long-term tumor response. The fluorescence at the near-infrared (NIR) region of the PS-NIR fluorophore conjugate was assessed intermittently via fluorescence imaging. The loss of fluorescence, photobleaching, caused by singlet oxygen from the PS was mapped continuously during PDT. The tumor responses (BALB/c mice bearing Colon26 tumors) were assessed after PDT by measuring tumor sizes daily. Our results showed distinctive photobleaching kinetics rates between the PS and CD. Interestingly, compared to higher light fluence, the tumors exposed at low light fluence showed reduced photobleaching and enhanced long-term PDT efficacy. The presence of NIR fluorophore in PS-CD conjugates provides an opportunity of fluorescence imaging and monitoring the photobleaching rate of the CD moiety for large and deeply seated tumors and assessing PDT tumor response in real-time. View Full-Text
Keywords: Photodynamic therapy; photobleaching; photosensitizers; fluorescence imaging Photodynamic therapy; photobleaching; photosensitizers; fluorescence imaging
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

James, N.S.; Cheruku, R.R.; Missert, J.R.; Sunar, U.; Pandey, R.K. Measurement of Cyanine Dye Photobleaching in Photosensitizer Cyanine Dye Conjugates Could Help in Optimizing Light Dosimetry for Improved Photodynamic Therapy of Cancer. Molecules 2018, 23, 1842.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Molecules EISSN 1420-3049 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top