title: Treatment of near-infrared photodynamic therapy using a liposomally formulated indocyanine green derivative for squamous cell carcinoma.
abstract: BACKGROUND
  Photodynamic therapy (PDT) is a less invasive option for cancer treatment that has evolved through recent developments in nanotechnology. We have designed and synthesized a novel liposome system that includes an indocyanine green (ICG) derivative, ICG-C18, in its bilayer. In addition to its use as an optical imager to visualize blood, lymphatic, and bile flow, ICG has also been used as an optical sensitizer. In the present report, we evaluate the use of our novel liposome system, LP-ICG-C18, in PDT for squamous cell carcinoma in an autologous murine model.
  
  
  METHODS
  An excitation pulse beam (300 μJ/pulse) of a single band (800 nm) was used for sensitization. The cytotoxicity of the photodynamic therapy was evaluated in terms of cellular morphology changes, methyl thiazolyl tetrazolium (MTT) assay results, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining. We tested the enhanced permeability and retention effect of LP-ICG-C18 in tumor-bearing C3H/He mice using a near-infrared fluorescence imaging system and fluorescence microscopy. We also examined the antitumor effect of PDT by measuring tumor volume in tumor-bearing mice.
  
  
  RESULTS
  Cell death and apoptosis were only observed in the PDT group receiving LP-ICG-C18. LP-ICG-C18 itself had no cytotoxic activity and showed good biocompatibility. LP-ICG-C18 accumulated on the tumor 24 hours after injection and was retained for approximately 3 weeks. Tumor cell apoptosis following PDT with LP-ICG-C18 was also observed under optical microscopy, MTT assay, and TUNEL staining.
  
  
  CONCLUSIONS
  These findings suggest that LP-ICG-C18 may be an effective intervening material in PDT for malignant disease.
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Tetsuro
authors: T
authors: Maruyama
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Yasunori
authors: Y
authors: Akutsu
authors: Department of Bioinformatics, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Akiko
authors: A
authors: Suganami
authors: Department of Bioinformatics, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Yutaka
authors: Y
authors: Tamura
authors: Department of Medical System Engineering, Faculty of Engineering, Chiba University, Chiba, Japan.
authors: Hiromichi
authors: H
authors: Fujito
authors: Division of Nanoscience, Graduate School of Advanced Integration Science, Chiba University, Chiba, Japan.
authors: Tomoki
authors: T
authors: Ouchi
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Naoki
authors: N
authors: Akanuma
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Yuka
authors: Y
authors: Isozaki
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Nobuyoshi
authors: N
authors: Takeshita
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Isamu
authors: I
authors: Hoshino
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Masaya
authors: M
authors: Uesato
authors: Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors: Taro
authors: T
authors: Toyota
authors: Center for Frontier Medical Engineering, Chiba University, Chiba, Japan.
authors: Hideki
authors: H
authors: Hayashi
authors: Department of Frontier Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors: Hisahiro
authors: H
authors: Matsubara
mesh_terms: D000818:Animals; D001692:Biological Transport; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D002626:Chemistry, Pharmaceutical; D005260:Female; D057927:Hydrophobic and Hydrophilic Interactions; D007208:Indocyanine Green / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D007259:Infrared Rays; D008081:Liposomes; D051379:Mice; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D013696:Temperature
chemical_list: D008081:Liposomes; D017319:Photosensitizing Agents; D007208:Indocyanine Green