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Comparative hyperthermia effects of silica-gold nanoshells with different surface coverage of gold clusters on epithelial tumor cells.

Park SE, Lee J, Lee T, Bae SB, Kang B, Huh YM, Lee SW, Haam S - Int J Nanomedicine (2015)

Bottom Line: Silica-gold nanoshell (SGNS), which is a silica core surrounded by a gold layer, was synthesized by seed-mediated coalescence of gold clusters in an electroless plating solution.SGNS variations with different surface coverage of gold clusters were prepared by adjusting the amounts of gold salts in the presence of formaldehyde-reducing agents.Fully covered SGNS (f-SGNS) with connected gold clusters exhibited stronger intensity and more redshift of plasmon bands located around 820 nm than those of partially covered SGNS (p-SGNS) with disconnected gold clusters.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biochemical Engineering, Gachon University, Gyeonggi-Do, Republic of Korea.

ABSTRACT
Silica-gold nanoshell (SGNS), which is a silica core surrounded by a gold layer, was synthesized by seed-mediated coalescence of gold clusters in an electroless plating solution. SGNS variations with different surface coverage of gold clusters were prepared by adjusting the amounts of gold salts in the presence of formaldehyde-reducing agents. Fully covered SGNS (f-SGNS) with connected gold clusters exhibited stronger intensity and more redshift of plasmon bands located around 820 nm than those of partially covered SGNS (p-SGNS) with disconnected gold clusters. Upon irradiation with near-infrared light (30 W/cm(2), 700-800 nm), f-SGNS caused a larger hyperthermia effect, generating a large temperature change (ΔT =42°C), as compared to the relatively small temperature change (ΔT =24°C) caused by p-SGNS. The therapeutic antibody, Erbitux™ (ERB), was further conjugated to SGNS for specific tumor cell targeting. The f-ERB-SGNS showed excellent therapeutic efficacy based on the combined effect of both the therapeutic antibody and the full hyperthermia dose under near-infrared irradiation. Thus, SGNS with well-controlled surface morphology of gold shells may be applicable for near-infrared-induced hyperthermia therapy with tunable optical properties.

No MeSH data available.


Related in: MedlinePlus

Combined imaging and therapy of epidermoid carcinoma A431 cell line and MCF7 cell line (with different levels of EGFR overexpression). Cytotoxicity of control samples was tested using cells treated with an NIR-emitting laser only. Images of cells (A431, MCF7) targeted with ERB-SGNS were obtained upon exposure to increasing laser intensity (200, 400, 600 mW). Cell viabilities were estimated by calcein staining (Molecular Probes, 1 μM).Abbreviations: SGNS, silica–gold nanoshell; p-SGNS, partially covered-silica–gold nanoshell; f-SGNS, fully covered-silica–gold nanoshell; Conc, concentration; EGFR, epidermal growth factor receptor; NIR, near infra-red; ERB, Erbitux™; p-ERB-SGNS, ERB-conjugated partially covered SGNS; f-ERB-SGNS, ERB-conjugated fully covered SGNS; MTT, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide.
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f7-ijn-10-261: Combined imaging and therapy of epidermoid carcinoma A431 cell line and MCF7 cell line (with different levels of EGFR overexpression). Cytotoxicity of control samples was tested using cells treated with an NIR-emitting laser only. Images of cells (A431, MCF7) targeted with ERB-SGNS were obtained upon exposure to increasing laser intensity (200, 400, 600 mW). Cell viabilities were estimated by calcein staining (Molecular Probes, 1 μM).Abbreviations: SGNS, silica–gold nanoshell; p-SGNS, partially covered-silica–gold nanoshell; f-SGNS, fully covered-silica–gold nanoshell; Conc, concentration; EGFR, epidermal growth factor receptor; NIR, near infra-red; ERB, Erbitux™; p-ERB-SGNS, ERB-conjugated partially covered SGNS; f-ERB-SGNS, ERB-conjugated fully covered SGNS; MTT, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide.

Mentions: To determine the turmoricidal efficacies of NIR laser treatment modalities, cancer cells were incubated with the prepared NPs after laser exposure. The therapeutic efficacies of p-ERB-SGNS and f-ERB-SGNS were then examined with respect to laser intensity and the concentration of SGNS against the cancer cell lines A431 and MCF7 cells with different EGFR overexpression levels. The viability of MCF7 and A431 cells was not influenced by the intensity of NIR-laser only (Figure 7, control). The f-ERB-SGNS- and p-ERB-SGNS-treated MCF7 cells showed strong emission after calcein AM staining. Calcein AM does not dye dead cells; this demonstrated that MCF7 cells did not heal by hyperthermia because of low EGFR receptor level. However, A431 cells had high EGFR receptor levels. Therefore, f-ERB-SGNS- and p-ERB-SGNS-treated A431 cells emitted weak light because of the hyperthermia effect from NIR-absorbing nanoshells (such as f-SGNS and p-SGNS). Particularly, we quantified cell viabilities after treatment with 0.4 mg/L of p-ERG-SGNS and 0.4 mg/L of f-ERB-SGNS by measuring the relative fluorescence intensities. The cellular viability of the control group was considered to be 100%. Cell viability after f-ERB-SGNS treatment of A431 cells was 20.57%±0.23% which was lower than that of p-ERB-SGNS (45.25%±1.5%). The therapeutic efficacy of f-SGNS was confirmed to be better than that of p-SGNS, which was expected based on the strong NIR absorbance of f-SGNS. Additionally, both p-ERB-SGNS- and f-ERB-SGNS-treated MCF7 cells showed relatively high cell viabilities (0.4 mg/L of p-SGNS-treated MCF7 cells: 98.95%±0.4% and 0.4 mg/L of f-SGNS-treated MCF7 cells: 98.95%±0.8%), indicating that there was no photothermal therapeutic effect on MCF7 cells caused by the antibody (ERB) on NP surface. Thus, we evaluated the increased therapeutic efficacy by f-ERB-SGNS under high-intensity NIR irradiation.


Comparative hyperthermia effects of silica-gold nanoshells with different surface coverage of gold clusters on epithelial tumor cells.

Park SE, Lee J, Lee T, Bae SB, Kang B, Huh YM, Lee SW, Haam S - Int J Nanomedicine (2015)

Combined imaging and therapy of epidermoid carcinoma A431 cell line and MCF7 cell line (with different levels of EGFR overexpression). Cytotoxicity of control samples was tested using cells treated with an NIR-emitting laser only. Images of cells (A431, MCF7) targeted with ERB-SGNS were obtained upon exposure to increasing laser intensity (200, 400, 600 mW). Cell viabilities were estimated by calcein staining (Molecular Probes, 1 μM).Abbreviations: SGNS, silica–gold nanoshell; p-SGNS, partially covered-silica–gold nanoshell; f-SGNS, fully covered-silica–gold nanoshell; Conc, concentration; EGFR, epidermal growth factor receptor; NIR, near infra-red; ERB, Erbitux™; p-ERB-SGNS, ERB-conjugated partially covered SGNS; f-ERB-SGNS, ERB-conjugated fully covered SGNS; MTT, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4583537&req=5

f7-ijn-10-261: Combined imaging and therapy of epidermoid carcinoma A431 cell line and MCF7 cell line (with different levels of EGFR overexpression). Cytotoxicity of control samples was tested using cells treated with an NIR-emitting laser only. Images of cells (A431, MCF7) targeted with ERB-SGNS were obtained upon exposure to increasing laser intensity (200, 400, 600 mW). Cell viabilities were estimated by calcein staining (Molecular Probes, 1 μM).Abbreviations: SGNS, silica–gold nanoshell; p-SGNS, partially covered-silica–gold nanoshell; f-SGNS, fully covered-silica–gold nanoshell; Conc, concentration; EGFR, epidermal growth factor receptor; NIR, near infra-red; ERB, Erbitux™; p-ERB-SGNS, ERB-conjugated partially covered SGNS; f-ERB-SGNS, ERB-conjugated fully covered SGNS; MTT, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide.
Mentions: To determine the turmoricidal efficacies of NIR laser treatment modalities, cancer cells were incubated with the prepared NPs after laser exposure. The therapeutic efficacies of p-ERB-SGNS and f-ERB-SGNS were then examined with respect to laser intensity and the concentration of SGNS against the cancer cell lines A431 and MCF7 cells with different EGFR overexpression levels. The viability of MCF7 and A431 cells was not influenced by the intensity of NIR-laser only (Figure 7, control). The f-ERB-SGNS- and p-ERB-SGNS-treated MCF7 cells showed strong emission after calcein AM staining. Calcein AM does not dye dead cells; this demonstrated that MCF7 cells did not heal by hyperthermia because of low EGFR receptor level. However, A431 cells had high EGFR receptor levels. Therefore, f-ERB-SGNS- and p-ERB-SGNS-treated A431 cells emitted weak light because of the hyperthermia effect from NIR-absorbing nanoshells (such as f-SGNS and p-SGNS). Particularly, we quantified cell viabilities after treatment with 0.4 mg/L of p-ERG-SGNS and 0.4 mg/L of f-ERB-SGNS by measuring the relative fluorescence intensities. The cellular viability of the control group was considered to be 100%. Cell viability after f-ERB-SGNS treatment of A431 cells was 20.57%±0.23% which was lower than that of p-ERB-SGNS (45.25%±1.5%). The therapeutic efficacy of f-SGNS was confirmed to be better than that of p-SGNS, which was expected based on the strong NIR absorbance of f-SGNS. Additionally, both p-ERB-SGNS- and f-ERB-SGNS-treated MCF7 cells showed relatively high cell viabilities (0.4 mg/L of p-SGNS-treated MCF7 cells: 98.95%±0.4% and 0.4 mg/L of f-SGNS-treated MCF7 cells: 98.95%±0.8%), indicating that there was no photothermal therapeutic effect on MCF7 cells caused by the antibody (ERB) on NP surface. Thus, we evaluated the increased therapeutic efficacy by f-ERB-SGNS under high-intensity NIR irradiation.

Bottom Line: Silica-gold nanoshell (SGNS), which is a silica core surrounded by a gold layer, was synthesized by seed-mediated coalescence of gold clusters in an electroless plating solution.SGNS variations with different surface coverage of gold clusters were prepared by adjusting the amounts of gold salts in the presence of formaldehyde-reducing agents.Fully covered SGNS (f-SGNS) with connected gold clusters exhibited stronger intensity and more redshift of plasmon bands located around 820 nm than those of partially covered SGNS (p-SGNS) with disconnected gold clusters.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biochemical Engineering, Gachon University, Gyeonggi-Do, Republic of Korea.

ABSTRACT
Silica-gold nanoshell (SGNS), which is a silica core surrounded by a gold layer, was synthesized by seed-mediated coalescence of gold clusters in an electroless plating solution. SGNS variations with different surface coverage of gold clusters were prepared by adjusting the amounts of gold salts in the presence of formaldehyde-reducing agents. Fully covered SGNS (f-SGNS) with connected gold clusters exhibited stronger intensity and more redshift of plasmon bands located around 820 nm than those of partially covered SGNS (p-SGNS) with disconnected gold clusters. Upon irradiation with near-infrared light (30 W/cm(2), 700-800 nm), f-SGNS caused a larger hyperthermia effect, generating a large temperature change (ΔT =42°C), as compared to the relatively small temperature change (ΔT =24°C) caused by p-SGNS. The therapeutic antibody, Erbitux™ (ERB), was further conjugated to SGNS for specific tumor cell targeting. The f-ERB-SGNS showed excellent therapeutic efficacy based on the combined effect of both the therapeutic antibody and the full hyperthermia dose under near-infrared irradiation. Thus, SGNS with well-controlled surface morphology of gold shells may be applicable for near-infrared-induced hyperthermia therapy with tunable optical properties.

No MeSH data available.


Related in: MedlinePlus