Article Title
Gold nanorod-photosensitizer conjugate with extracellular pH-driven tumor targeting ability for photothermal/photodynamic therapy
Authors
Nannan Wang, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Zilong Zhao, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Yifan Lv, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Huanhuan Fan, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Huarong Bai, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Hongmin Meng, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Yuqian Long, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Ting Fu, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Xiaobing Zhang, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Weihong Tan, Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, and Collaborative Research Center of Molecular Engineering for Theranostics, Hunan University, Changsha 410082, China
Department of Chemistry and Department of Physiology and Functional Genomics, Center for Research at Bio/nano Interface, Shands Cancer Center, UF Genetics Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, USA
Keywords
photodynamic therapy, photothermal therapy, gold nanorods, targeting acidity, peptide
Abstract
Chlorin e6–pHLIPss–AuNRs, a gold nanorod–photosensitizer conjugate containing a pH (low) insertion peptide (pHLIP) with a disulfide bond which imparts extracellular pH (pHe)-driven tumor targeting ability, has been successfully developed for bimodal photodynamic and photothermal therapy. In this bimodal therapy, chlorin e6 (Ce6), a second-generation photosensitizer (PS), is used for photodynamic therapy (PDT). Gold nanorods (AuNRs) are used as a hyperthermia agent for photothermal therapy (PTT) and also as a nanocarrier and quencher of Ce6. pHLIPss is designed as a pHe-driven targeting probe to enhance accumulation of Ce6 and AuNRs in cancer cells at low pH. In Ce6– pHLIPss–AuNRs, Ce6 is close to and quenched by AuNRs, causing little PDT effect. When exposed to normal physiological pH 7.4, Ce6–pHLIPss–AuNRs loosely associate with the cell membrane. However, once exposed to acidic pH 6.2, pHLIP actively inserts into the cell membrane, and the conjugates are translocated into cells. When this occurs, Ce6 separates from the AuNRs as a result of disulfide bond cleavage caused by intracellular glutathione (GSH), and singlet oxygen is produced for PDT upon light irradiation. In addition, as individual PTT agent, AuNRs can enhance the accumulation of PSs in the tumor by the enhanced permeation and retention (EPR) effect. Therefore, as indicated by our data, when exposed to acidic pH, Ce6–pHLIPss–AuNRs can achieve synergistic PTT/PDT bimodality for cancer treatment.
Graphical Abstract

Publisher
Tsinghua University Press
Recommended Citation
Nannan Wang,Zilong Zhao,Yifan Lv,Huanhuan Fan,Huarong Bai,Hongmin Meng,Yuqian Long,Ting Fu,Xiaobing Zhang,Weihong Tan, Gold nanorod-photosensitizer conjugate with extracellular pH-driven tumor targeting ability for photothermal/photodynamic therapy. NanoRes.2014, 7(9): 1291–1301