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Fabrication of graphene-isolated-Au-nanocrystal nanostructures for multimodal cell imaging and photothermal-enhanced chemotherapy.

Bian X, Song ZL, Qian Y, Gao W, Cheng ZQ, Chen L, Liang H, Ding D, Nie XK, Chen Z, Tan W - Sci Rep (2014)

Bottom Line: First, as surface-enhanced-Raman-scattering substrates, GIANs quench background fluorescence and reduce photocarbonization or photobleaching of analytes.Controlled release of DOX molecules from GIANs is achieved through NIR heating, significantly reducing the possibility of side effects in chemotherapy.The GIANs have high surface areas and stable thin shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.

View Article: PubMed Central - PubMed

Affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha, 410082, China.

ABSTRACT
Using nanomaterials to develop multimodal systems has generated cutting-edge biomedical functions. Herein, we develop a simple chemical-vapor-deposition method to fabricate graphene-isolated-Au-nanocrystal (GIAN) nanostructures. A thin layer of graphene is precisely deposited on the surfaces of gold nanocrystals to enable unique capabilities. First, as surface-enhanced-Raman-scattering substrates, GIANs quench background fluorescence and reduce photocarbonization or photobleaching of analytes. Second, GIANs can be used for multimodal cell imaging by both Raman scattering and near-infrared (NIR) two-photon luminescence. Third, GIANs provide a platform for loading anticancer drugs such as doxorubicin (DOX) for therapy. Finally, their NIR absorption properties give GIANs photothermal therapeutic capability in combination with chemotherapy. Controlled release of DOX molecules from GIANs is achieved through NIR heating, significantly reducing the possibility of side effects in chemotherapy. The GIANs have high surface areas and stable thin shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.

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NIR photothermal effect of GIANs.(a) Heating curve of 0.3 mg/mL GIAN solution using different power densities of an 808 nm NIR laser. (b) Heating curve of GIANs solution with different concentrations under 3 W/cm2 laser irradiation. (c) Bright field microscopy images of trypan blue-stained MCF-7 cells after different NIR photothermal treatments. Scale bar: 50 μm. (d) and (e), relative cell viability after treatment with different GIAN concentrations and different 808 nm laser irradiation times, respectively.
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f5: NIR photothermal effect of GIANs.(a) Heating curve of 0.3 mg/mL GIAN solution using different power densities of an 808 nm NIR laser. (b) Heating curve of GIANs solution with different concentrations under 3 W/cm2 laser irradiation. (c) Bright field microscopy images of trypan blue-stained MCF-7 cells after different NIR photothermal treatments. Scale bar: 50 μm. (d) and (e), relative cell viability after treatment with different GIAN concentrations and different 808 nm laser irradiation times, respectively.

Mentions: Graphitic nanomaterials have strong absorbance in the NIR region, making them suitable for NIR photothermal therapies252627283940. Au nanocrystals also have strong light absorbing capability, which makes them ideal for wide use in the photothermal therapy of cancers29303132. Combining the unique properties of graphitic and Au nanomaterials, GIANs demonstrated excellent photothermal heating capability. Fig. 5a shows the heating curve of 0.3 mg/mL GIANs solution under different power densities from 1 W/cm2 to 4 W/cm2 of an 808 nm NIR laser. After 8 minutes of 2 W/cm2 laser irradiation, the solution temperature increased to around 30°C, which is much higher than that of the 1 W/cm2 laser irradiation. We also investigated the concentration effect of photothermal heating (Fig. 5b). Upon increasing the concentration of GIANs, the solution temperature increased after 8 minutes of 3 W/cm2 laser irradiation. Au nanoparticles (0.3 mg/mL) were also used to compare heating efficiency, and a temperature increase similar to that of the 0.05 mg/mL GIAN solution was observed. The photothermal heating of GIAN is very stable, even under prolonged laser irradiation time, because of the highly stable graphene-isolated shells on the GIANs (Supplementary, Fig. S6).


Fabrication of graphene-isolated-Au-nanocrystal nanostructures for multimodal cell imaging and photothermal-enhanced chemotherapy.

Bian X, Song ZL, Qian Y, Gao W, Cheng ZQ, Chen L, Liang H, Ding D, Nie XK, Chen Z, Tan W - Sci Rep (2014)

NIR photothermal effect of GIANs.(a) Heating curve of 0.3 mg/mL GIAN solution using different power densities of an 808 nm NIR laser. (b) Heating curve of GIANs solution with different concentrations under 3 W/cm2 laser irradiation. (c) Bright field microscopy images of trypan blue-stained MCF-7 cells after different NIR photothermal treatments. Scale bar: 50 μm. (d) and (e), relative cell viability after treatment with different GIAN concentrations and different 808 nm laser irradiation times, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151100&req=5

f5: NIR photothermal effect of GIANs.(a) Heating curve of 0.3 mg/mL GIAN solution using different power densities of an 808 nm NIR laser. (b) Heating curve of GIANs solution with different concentrations under 3 W/cm2 laser irradiation. (c) Bright field microscopy images of trypan blue-stained MCF-7 cells after different NIR photothermal treatments. Scale bar: 50 μm. (d) and (e), relative cell viability after treatment with different GIAN concentrations and different 808 nm laser irradiation times, respectively.
Mentions: Graphitic nanomaterials have strong absorbance in the NIR region, making them suitable for NIR photothermal therapies252627283940. Au nanocrystals also have strong light absorbing capability, which makes them ideal for wide use in the photothermal therapy of cancers29303132. Combining the unique properties of graphitic and Au nanomaterials, GIANs demonstrated excellent photothermal heating capability. Fig. 5a shows the heating curve of 0.3 mg/mL GIANs solution under different power densities from 1 W/cm2 to 4 W/cm2 of an 808 nm NIR laser. After 8 minutes of 2 W/cm2 laser irradiation, the solution temperature increased to around 30°C, which is much higher than that of the 1 W/cm2 laser irradiation. We also investigated the concentration effect of photothermal heating (Fig. 5b). Upon increasing the concentration of GIANs, the solution temperature increased after 8 minutes of 3 W/cm2 laser irradiation. Au nanoparticles (0.3 mg/mL) were also used to compare heating efficiency, and a temperature increase similar to that of the 0.05 mg/mL GIAN solution was observed. The photothermal heating of GIAN is very stable, even under prolonged laser irradiation time, because of the highly stable graphene-isolated shells on the GIANs (Supplementary, Fig. S6).

Bottom Line: First, as surface-enhanced-Raman-scattering substrates, GIANs quench background fluorescence and reduce photocarbonization or photobleaching of analytes.Controlled release of DOX molecules from GIANs is achieved through NIR heating, significantly reducing the possibility of side effects in chemotherapy.The GIANs have high surface areas and stable thin shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.

View Article: PubMed Central - PubMed

Affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University, Changsha, 410082, China.

ABSTRACT
Using nanomaterials to develop multimodal systems has generated cutting-edge biomedical functions. Herein, we develop a simple chemical-vapor-deposition method to fabricate graphene-isolated-Au-nanocrystal (GIAN) nanostructures. A thin layer of graphene is precisely deposited on the surfaces of gold nanocrystals to enable unique capabilities. First, as surface-enhanced-Raman-scattering substrates, GIANs quench background fluorescence and reduce photocarbonization or photobleaching of analytes. Second, GIANs can be used for multimodal cell imaging by both Raman scattering and near-infrared (NIR) two-photon luminescence. Third, GIANs provide a platform for loading anticancer drugs such as doxorubicin (DOX) for therapy. Finally, their NIR absorption properties give GIANs photothermal therapeutic capability in combination with chemotherapy. Controlled release of DOX molecules from GIANs is achieved through NIR heating, significantly reducing the possibility of side effects in chemotherapy. The GIANs have high surface areas and stable thin shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.

Show MeSH