Back to Journals » International Journal of Nanomedicine » Volume 10 » Issue 1

Effective near-infrared photodynamic therapy assisted by upconversion nanoparticles conjugated with photosensitizers

Authors Dou QQ, Teng CP, Ye E, Loh XJ

Received 25 September 2014

Accepted for publication 25 October 2014

Published 8 January 2015 Volume 2015:10(1) Pages 419—432


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 3

Editor who approved publication: Prof. Dr. Thomas J. Webster

Qing Qing Dou,1 Choon Peng Teng,1 Enyi Ye,1 Xian Jun Loh1–3

1Institute of Materials Research and Engineering, A*STAR, Singapore; 2Department of Materials Science and Engineering, National University of Singapore, Singapore; 3Singapore Eye Research Institute, Singapore

Abstract: A drug model photosensitizer–conjugated upconversion nanoparticles nanocomplex was explored for application in near-infrared photodynamic therapy. As near-infrared penetrates deeper into the tissue, the model is useful for the application of photodynamic therapy in deeper tissue. The nanocomplex that was synthesized had low polydispersity, and the upconversion nanoparticle was covalently conjugated with the photosensitizer. The robust bond could prevent the undesired premature release of photosensitizer and also enhance the singlet-oxygen generation. Singlet-oxygen generation rate from this nanocomplex was evaluated in solution. The photodynamic therapy effect was assessed with MCF-7 cells in two different methods, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead assay. The assay results showed that promising efficacy (>90%) can be achieved with a low concentration (50 µg mL-1) of this nanocomplex and mild dosage (7 mW cm-2) of near-infrared laser treatment.

Keywords: nanocomplex, singlet-oxygen generation rate, MTT assay, live/dead assay

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]