Antimicrobial photodynamic activity and cytocompatibility of Au25(Capt)18 clusters photoexcited by blue LED light irradiation

• Miyata, Saori

• Miyaji, Hirofumi

• Kawasaki, Hideya

• Yamamoto, Masaki

• Nishida, Erika

• Takita, Hiroko

• Akasaka, Tsukasa

• Ushijima, Natsumi

• Iwanaga, Toshihiko

• Sugaya, Tsutomu

抄録

Antimicrobial photodynamic therapy (aPDT) has beneficial effects in dental treatment. We applied captopril-protected gold (Au25(Capt)18) clusters as a novel photosensitizer for aPDT. Photoexcited Au clusters under light irradiation generated singlet oxygen (1O2). Accordingly, the antimicrobial and cytotoxic effects of Au25(Capt)18 clusters under dental blue light-emitting diode (LED) irradiation were evaluated. 1O2 generation of Au25(Capt)18 clusters under blue LED irradiation (420–460 nm) was detected by a methotrexate (MTX) probe. The antimicrobial effects of photoexcited Au clusters (0, 5, 50, and 500 μg/mL) on oral bacterial cells, such as Streptococcus mutans, Aggregatibacter actinomycetemcomitans, and Porphyromonas gingivalis, were assessed by morphological observations and bacterial growth experiments. Cytotoxicity testing of Au clusters and blue LED irradiation was then performed against NIH3T3 and MC3T3-E1 cells. In addition, the biological performance of Au clusters (500 μg/mL) was compared to an organic dye photosensitizer, methylene blue (MB; 10 and 100 μg/mL). We confirmed the 1O2 generation ability of Au25(Capt)18 clusters through the fluorescence spectra of oxidized MTX. Successful application of photoexcited Au clusters to aPDT was demonstrated by dose-dependent decreases in the turbidity of oral bacterial cells. Morphological observation revealed that application of Au clusters stimulated destruction of bacterial cell walls and inhibited biofilm formation. Aggregation of Au clusters around bacterial cells was fluorescently observed. However, photoexcited Au clusters did not negatively affect the adhesion, spreading, and proliferation of mammalian cells, particularly at lower doses. In addition, application of Au clusters demonstrated significantly better cytocompatibility compared to MB. We found that a combination of Au25(Capt)18 clusters and blue LED irradiation exhibited good antimicrobial effects through 1O2 generation and biosafe characteristics, which is desirable for aPDT in dentistry.

収録刊行物

• International Journal of Nanomedicine

  International Journal of Nanomedicine 12 2703-2716, 2017-04-04

  Dove Medical Press

キーワード

• Aggregatibacter actinomycetemcomitans
• antimicrobial photodynamic therapy
• photosensitizer
• Porphyromonas gingivalis
• singlet oxygen
• Streptococcus mutans

詳細情報

• CRID: 1050282813999598336
• NII論文ID: 120006024358
• NII書誌ID: AA1215861X
• ISSN: 11782013
• ISSN: 11769114
• HANDLE: 2115/65029
• 本文言語コード: en
• 資料種別: journal article
• データソース種別:
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  • CiNii Articles