||Antibacterial and cytotoxic effects of photoexcited Au clusters via blue high-power or white low-power light emitting diode irradiation
Miyata, Saori Miyaji, Hirofumi ,
Kawasaki, Hideya ,
Nishida, Erika ,
Shitomi, Kanako Akasaka, Tsukasa ,
Tanaka, Saori ,
Iizuka, TadashiSugaya, Tsutomu
Biology, Engineering and Medicine
2017-10 , Open Access Text
The development of photosensitizers and light sources has enabled the use of antimicrobial photodynamic therapy (aPDT) in various dental therapies. In the present
study, we compared the antibacterial and cytotoxic effects of Au clusters photoexcited by blue and white LED irradiation. We fabricated novel photosensitizers,
captopril-protected gold (Capt-Au) clusters and lysozyme-stabilized gold (Lyz-Au) clusters, for aPDT. Au clusters were then photoexcited by two kinds of light
sources, blue high-power and white low-power light-emitting diodes (LEDs). Since white LED contains a wide spectrum of light (400–750 nm), white LED would
be relevant for aPDT even if using a low-power source.
The turbidity and viability of Streptococcus mutans were assessed following application of Capt-Au clusters (500 μg/mL) or Lyz-Au clusters (1,000 μg/mL) photoexcited
by a blue high-power LED (1,000 mW/cm2) or white low-power LED (80 mW/cm2). In addition, the cytotoxicity of Au clusters and LED irradiation was evaluated
in NIH3T3 and MC3T3-E1 cells.
Au clusters photoexcited by the white low-power LED equally decreased the turbidity and viability of S. mutans compared with blue high-power LED. However,
Au clusters photoexcited by white LED irradiation caused decreased cytotoxicity in mammalian cells compared with those photoexcited by blue LED irradiation. In
conclusion, white LEDs possess biosafe properties for aPDT using Au clusters.