Comparison Study of Gold Nanohexapods, Nanorods, and Nanocages for Photothermal Cancer Treatment

Abstract

Gold nanohexapods represent a novel class of optically tunable nanostructures consisting of an octahedral core and six arms grown on its vertices. By controlling the length of the arms, their localized surface plasmon resonance peaks could be tuned from the visible to the near-infrared region for deep penetration of light into soft tissues. Herein we compare the in vitro and in vivo capabilities of Au nanohexapods as photothermal transducers for theranostic applications by benchmarking against those of Au nanorods and nanocages. While all these Au nanostructures could absorb and convert near-infrared light into heat, Au nanohexapods exhibited the highest cellular uptake and the lowest cytotoxicity in vitro for both the as-prepared and PEGylated nanostructures. In vivo pharmacokinetic studies showed that the PEGylated Au nanohexapods had significant blood circulation and tumor accumulation in a mouse breast cancer model. Following photothermal treatment, substantial heat was produced in situ and the tumor metabolism was greatly reduced for all these Au nanostructures, as determined with 18F-flourodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Combined together, we can conclude that Au nanohexapods are promising candidates for cancer theranostics in terms of both photothermal destruction and contrast-enhanced diagnosis.

Recent Advances in Nanoparticle Shape and Composition Regulation Based on Galvanic Replacement for Cancer Treatment

“…Furthermore, the NIR-region absorbance endowed by the hollow nanocage structures corresponds to the photothermal therapeutic wavelength window, which does not overlap with the light absorbing region of substances in the body such as hemoglobin, fat, and water. Since the tissue penetration of NIR light is superior to that of visible light and ultraviolet rays, it presents huge advantages when combined with hollow nanoparticles [134][135][136][137][138][139][140][141][142][143].…”

Anisotropic Gold-based Nanoparticles: Preparation, Properties, and Applications

“…98,102104 Gold nanocages are also a powerful candidate as a photothermal transducer for photothermal therapy. 104,105 In this application, gold nanocages were modified with PEG, and then injected intravenously into tumor-bearing mice. Irradiation of the tumor sites increased their temperature, and the tumor damage observed was comparable with the case of gold nanorods.…”

“…Irradiation of the tumor sites increased their temperature, and the tumor damage observed was comparable with the case of gold nanorods. 104 In this report, gold nanohexapods were compared with gold nanorods and nanocages for photothermal therapy in tumorbearing mice. PEG-modified gold nanohexapods exhibited the highest photothermal effect at the tumor, and showed longlasting blood circulation after intravenous injection (Figure 12).…”

Gold nanoparticles for cancer theranostics — A brief update

“…Hence, di®erent sizes and shapes of AuNPs provide various photothermal destruction during cancer treatment. 63 Cancer seeking molecules conjugated gold nanorods are potential PA targeting imaging agents for cancer detection in vivo because their strong absorption of light and characters of plasmon resonance absorption and scatter in NIR. 64,65 Recently, a novel colloidal hybrid nanostructure with goldbased tripod architecture was designed and prepared for better targeted molecular PA imaging of tumor tissues in vivo.…”