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

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.

Comparison of Four Common Gold Nanoparticles for Photothermal Cancer Therapy: A Review

“…To test the toxicity in vitro, glucose was attached to increase the uptake by cells [17]. Melanoma cells (B16-F10) were incubated with AuNRs for a day and then an MTT assay was used to measure metabolic activity and overall cell viability [17,55]. This is ultimately a colorimetric assay that depends on mitochondrial oxidation of the cells in question [55].…”

“…Melanoma cells (B16-F10) were incubated with AuNRs for a day and then an MTT assay was used to measure metabolic activity and overall cell viability [17,55]. This is ultimately a colorimetric assay that depends on mitochondrial oxidation of the cells in question [55]. Fluorescence microscopy was used to ensure that uptake of AuNRs by the cells occurred [17].…”

“…6 GOLD NANOSHELLS AuNShs consist of a core material that lacks electrical conductivity and a gold shell [62,63]. There are many variations in the cores of nanoshells, such as gold-sulfide, polystyrene latex sphere, and silica [55]. These types of nanoshells appear to be promising for cancer treatment, as their optical properties have a changeable plasmon resonance in the NIR region [55].…”

“…There are many variations in the cores of nanoshells, such as gold-sulfide, polystyrene latex sphere, and silica [55]. These types of nanoshells appear to be promising for cancer treatment, as their optical properties have a changeable plasmon resonance in the NIR region [55]. Specific types of AuNSh have size limitations and can potentially form by-products during the fabrication process that can negatively interfere with the hyperthermia treatment [64,55].…”

Laser Auto Fluorescence and Dye-enhanced Spectroscopic Detection of Normal and Cancerous Human Lung Cell Lines and Plasmonic Photothermal Heating

“…For example, plasmonic nanoshell-mediated laser hyperthermia is currently emerging as a novel approach of cancer therapy where the cancer cells are destroyed through laser-induced heating of on the surface or within the cells [19,20]. Basically, a nanoshell (NS) involves plasmon, which is basically a collective excitation or quantum plasma oscillation where the electrons simultaneously oscillate with respect to all the ions.…”