Photosensitizer Loaded Nano-Graphene for Multimodality Imaging Guided Tumor Photodynamic Therapy

Pengfei Rong^1,2,3*, Kai Yang^2,4*, Avinash Srivastan², Dale O. Kiesewetter², Xuyi Yue^2,5, Fu Wang², Liming Nie^2,5, Ashwinkumar Bhirde², Zhe Wang², Zhuang Liu⁴, Gang Niu^2✉, Wei Wang^1✉, Xiaoyuan Chen^{2 ✉}

1. Department of Radiology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, China
2. Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, Maryland 20892, United States
3. State Key Laboratory for Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China
4. Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, China
5. Center for Molecular Imaging and Translational Medicine, School of Public Health, Xiamen University, Xiamen, Fujian 361102, China
* These authors contributed equally to this work.

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Citation:
Rong P, Yang K, Srivastan A, Kiesewetter DO, Yue X, Wang F, Nie L, Bhirde A, Wang Z, Liu Z, Niu G, Wang W, Chen X. Photosensitizer Loaded Nano-Graphene for Multimodality Imaging Guided Tumor Photodynamic Therapy. Theranostics 2014; 4(3):229-239. doi:10.7150/thno.8070. Available from http://www.thno.org/v04p0229.htm

Abstract

Graphene, a 2-dimensional carbon nanomaterial, has attracted wide attention in biomedical applications, owing to its intrinsic physical and chemical properties. In this work, a photosensitizer molecule, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-alpha (HPPH or Photochlor®), is loaded onto polyethylene glycol (PEG)-functionalized graphene oxide (GO) via supramolecular π-π stacking. The obtained GO-PEG-HPPH complex shows high HPPH loading efficiency. The in vivo distribution and delivery were tracked by fluorescence imaging as well as positron emission tomography (PET) after radiolabeling of HPPH with ⁶⁴Cu. Compared with free HPPH, GO-PEG-HPPH offers dramatically improved photodynamic cancer cell killing efficacy due to the increased tumor delivery of HPPH. Our study identifies a role for graphene as a carrier of PDT agents to improve PDT efficacy and increase long-term survival following treatment.

Keywords: Graphene oxide, HPPH, photodynamic therapy, positron emission tomography, optical imaging.