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Study on the visible-light-induced photokilling effect of nitrogen-doped TiO2 nanoparticles on cancer cells.

Li Z, Mi L, Wang PN, Chen JY - Nanoscale Res Lett (2011)

Bottom Line: However, the visible-light-induced photokilling effects on cells were observed.The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles.The reactive oxygen species was found to play an important role on the photokilling effect for cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China. lanmi@fudan.edu.cn.

ABSTRACT
Nitrogen-doped TiO2 (N-TiO2) nanoparticles were prepared by calcining the anatase TiO2 nanoparticles under ammonia atmosphere. The N-TiO2 showed higher absorbance in the visible region than the pure TiO2. The cytotoxicity and visible-light-induced phototoxicity of the pure- and N-TiO2 were examined for three types of cancer cell lines. No significant cytotoxicity was detected. However, the visible-light-induced photokilling effects on cells were observed. The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles. The cancer cells incubated with N-TiO2 were killed more effectively than that with the pure TiO2. The reactive oxygen species was found to play an important role on the photokilling effect for cells. Furthermore, the intracellular distributions of N-TiO2 nanoparticles were examined by laser scanning confocal microscopy. The co-localization of N-TiO2 nanoparticles with nuclei or Golgi complexes was observed. The aberrant nuclear morphologies such as micronuclei were detected after the N-TiO2-treated cells were irradiated by the visible light.

No MeSH data available.


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Raman and UV/Vis diffuse reflectance spectra of the nanoparticle samples. (a) Raman spectra of the pure and the three N-TiO2 nanoparticle samples. (b) Diffuse reflectance absorption spectra of samples pure, N-550-1, and N-550-2. Sample N-550-2 exhibited the highest absorbance in the visible region.
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Figure 1: Raman and UV/Vis diffuse reflectance spectra of the nanoparticle samples. (a) Raman spectra of the pure and the three N-TiO2 nanoparticle samples. (b) Diffuse reflectance absorption spectra of samples pure, N-550-1, and N-550-2. Sample N-550-2 exhibited the highest absorbance in the visible region.

Mentions: As shown in Table 1 and Figure 1a, the N-TiO2 samples N-550-1 and N-550-2 with the calcination temperature of 550°C, as well as the pure TiO2, exhibited a similar feature with five Raman peaks around 143, 197, 395, 514, and 640 cm-1, corresponding to the Raman fundamental modes of the anatase phase [15,16]. The Raman peaks for rutile phase [16] around 238, 420, and 614 cm-1 appeared when the calcination temperature was 600°C as shown in the spectrum of the sample N-600-1. It can be concluded that the phase of the TiO2 nanoparticles would transform from anatase to rutile when the calcination temperature increased to 600°C. Such a phase transformation will result in a decrease of the photocatalytic ability for TiO2 powders [17,18]. Therefore, we only used samples N-550-1 and N-550-2 for further studies.


Study on the visible-light-induced photokilling effect of nitrogen-doped TiO2 nanoparticles on cancer cells.

Li Z, Mi L, Wang PN, Chen JY - Nanoscale Res Lett (2011)

Raman and UV/Vis diffuse reflectance spectra of the nanoparticle samples. (a) Raman spectra of the pure and the three N-TiO2 nanoparticle samples. (b) Diffuse reflectance absorption spectra of samples pure, N-550-1, and N-550-2. Sample N-550-2 exhibited the highest absorbance in the visible region.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211446&req=5

Figure 1: Raman and UV/Vis diffuse reflectance spectra of the nanoparticle samples. (a) Raman spectra of the pure and the three N-TiO2 nanoparticle samples. (b) Diffuse reflectance absorption spectra of samples pure, N-550-1, and N-550-2. Sample N-550-2 exhibited the highest absorbance in the visible region.
Mentions: As shown in Table 1 and Figure 1a, the N-TiO2 samples N-550-1 and N-550-2 with the calcination temperature of 550°C, as well as the pure TiO2, exhibited a similar feature with five Raman peaks around 143, 197, 395, 514, and 640 cm-1, corresponding to the Raman fundamental modes of the anatase phase [15,16]. The Raman peaks for rutile phase [16] around 238, 420, and 614 cm-1 appeared when the calcination temperature was 600°C as shown in the spectrum of the sample N-600-1. It can be concluded that the phase of the TiO2 nanoparticles would transform from anatase to rutile when the calcination temperature increased to 600°C. Such a phase transformation will result in a decrease of the photocatalytic ability for TiO2 powders [17,18]. Therefore, we only used samples N-550-1 and N-550-2 for further studies.

Bottom Line: However, the visible-light-induced photokilling effects on cells were observed.The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles.The reactive oxygen species was found to play an important role on the photokilling effect for cells.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China. lanmi@fudan.edu.cn.

ABSTRACT
Nitrogen-doped TiO2 (N-TiO2) nanoparticles were prepared by calcining the anatase TiO2 nanoparticles under ammonia atmosphere. The N-TiO2 showed higher absorbance in the visible region than the pure TiO2. The cytotoxicity and visible-light-induced phototoxicity of the pure- and N-TiO2 were examined for three types of cancer cell lines. No significant cytotoxicity was detected. However, the visible-light-induced photokilling effects on cells were observed. The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles. The cancer cells incubated with N-TiO2 were killed more effectively than that with the pure TiO2. The reactive oxygen species was found to play an important role on the photokilling effect for cells. Furthermore, the intracellular distributions of N-TiO2 nanoparticles were examined by laser scanning confocal microscopy. The co-localization of N-TiO2 nanoparticles with nuclei or Golgi complexes was observed. The aberrant nuclear morphologies such as micronuclei were detected after the N-TiO2-treated cells were irradiated by the visible light.

No MeSH data available.


Related in: MedlinePlus