title: Stability enhanced polyelectrolyte-coated gold nanorod-photosensitizer complexes for high/low power density photodynamic therapy.
abstract: Photodynamic therapy (PDT) is a promising treatment modality for cancer and other malignant diseases, however safety and efficacy improvements are required before it reaches its full potential and wider clinical use. Herein, we investigated a highly efficient and safe photodynamic therapy procedure by developing a high/low power density photodynamic therapy mode (high/low PDT mode) using methoxypoly(ethylene glycol) thiol (mPEG-SH) modified gold nanorod (GNR)-AlPcS4 photosensitizer complexes. mPEG-SH conjugated to the surface of simple polyelectrolyte-coated GNRs was verified using Fourier transform infrared spectroscopy; this improved stability, reduced cytotoxicity, and increased the encapsulation and loading efficiency of the nanoparticle dispersions. The GNR-photosensitizer complexes were exposed to the high/low PDT mode (high light dose = 80 mW/cm(2) for 0.5 min; low light dose = 25 mW/cm(2) for 1.5 min), and a high PDT efficacy leads to approximately 90% tumor cell killing. Due to synergistic plasmonic photothermal properties of the complexes, the high/low PDT mode demonstrated improved efficacy over using single wavelength continuous laser irradiation. Additionally, no significant loss in viability was observed in cells exposed to free AlPcS4 photosensitizer under the same irradiation conditions. Consequently, free AlPcS4 released from GNRs prior to cellular entry did not contribute to cytotoxicity of normal cells or impose limitations on the use of the high power density laser. This high/low PDT mode may effectively lead to a safer and more efficient photodynamic therapy for superficial tumors.
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Zhenzhi
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Ren
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: An
authors.initials: A
authors.lastname: Gong
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Department of Biological Sciences, University of Wisconsin-Whitewater, Whitewater, WI 53190, USA.
authors.forename: Eric Michael Bratsolias
authors.initials: EM
authors.lastname: Brown
authors.affiliation: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Magnetic Materials and Devices, & Division of Functional Materials and Nanodevices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China. Electronic address: aiguo@nimte.ac.cn.
authors.forename: Aiguo
authors.initials: A
authors.lastname: Wu
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006801:Humans; D007211:Indoles / Q000737:chemistry; D061986:MCF-7 Cells; D053768:Metal Nanoparticles / Q000737:chemistry*; D018613:Microscopy, Confocal; D043942:Nanotubes / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D007211:Indoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; C048577:aluminum tetrasulfophthalocyanine; D006046:Gold
keywords: AlPcS4 photosensitizer; Gold nanorods; High/low power density; Near-infrared; Photodynamic therapy (PDT); Synergistic therapy