Exploring High Aspect Ratio Gold Nanotubes as Cytosolic Agents: Structural Engineering and Uptake into Mesothelioma Cells

Abstract

depends on their NIR optical absorption for photoresponses, and their structure and surface properties leading to low cytotoxicity and efficient cellular uptake. An important challenge for photo-triggered nanocarriers lies in their cellular confinement within membrane-bound vacuoles. [9] This can limit therapeutic benefit by adversely modifying their optical properties due to agglomeration, [10] or reducing the efficacy of delivering therapeutic payloads by phototriggered drug release. [11,12] Recent studies have revealed that silicon nanowires with lengths of several micrometers can enter cells via nonendocytic pathways and demonstrate cytosolic distribution. [13] We hypothesized that NIR-active 1D nanomaterials with similar structural parameters might circumvent the drawbacks of vesicular confinement. Gold nanotubes (AuNTs) represent an intriguing subset of 1D nanomaterials. Their accessible inner cavity can in principle be loaded with drugs, [14,15] their open ends can be used as gates for controlled drug release, [16] and their lower heat capacity enables better pulse heating for photoacoustic imaging and photothermal therapy. [17] Despite the potential merits of AuNTs, their lack of NIR absorption and our limited understanding of cellular interactions have hindered their exploitation. For example, the pentagonal AuNTs synthesized by Bi and The generation of effective and safe nanoagents for biological applications requires their physicochemical characteristics to be tunable, and their cellular interactions to be well characterized. Here, the controlled synthesis is developed for preparing high-aspect ratio gold nanotubes (AuNTs) with tailorable wall thickness, microstructure, composition, and optical characteristics. The modulation of optical properties generates AuNTs with strong near infrared absorption. Surface modification enhances dispersibility of AuNTs in aqueous media and results in low cytotoxicity. The uptake and trafficking of these AuNTs by primary mesothelioma cells demonstrate their accumulation in a perinuclear distribution where they are confined initially in membrane-bound vesicles from which they ultimately escape to the cytosol. This represents the first study of the cellular interactions of high-aspect ratio 1D metal nanomaterials and will facilitate the rational design of plasmonic nanoconstructs as cytosolic nanoagents for potential diagnosis and therapeutic applications.

Mechanochemical Synthesis of Dispersible Platinum Nanosheets for Enhanced Catalysis in a Microreactor

“…The properties of the nanostructured materials reflect their shape anisotropy. − The higher the aspect ratio of nanostructured noble metal is, the more its unique properties stand out: e.g., the catalytic activity of platinum nanosheets (PtNSs) and the near-infrared (NIR) absorption of gold nanotubes. , Nanostructured materials with shape anisotropy have been fabricated in various ways: seeding, hydrothermal, sol–gel, soft-template, and hard-template methods. In the fabrication of nanostructured materials, some self-assembly processes of the ingredients themselves or self-assembled templates are usually required to lead to the local anisotropy of the desired nanostructure by operating isotropic state functions like temperature and chemical composition, as shown in Figure a. − …”

Evaluating Phospholipid‐Functionalized Gold Nanorods for In Vivo Applications

“…[9,10] In this role, gold nanorods (AuNRs) are exceptionally well suited, offering a strong narrow absorbance peak, tunable throughout red and near-infrared (NIR) wavelengths. While other AuNP morphologies, including nanoplates, [11] nanotubes, [12,13] and nanoshells [14] offer absorbance peaks in the NIR, AuNRs have the highest absorbance cross-sections (σ abs ) per unit mass of any AuNP, with an σ abs typically an order of magnitude higher than that seen for Au nanoshells containing an equivalent mass of Au. [15] This is particularly advantageous in photothermal applications as the power of heat generation of an AuNP is proportional to its σ abs at the illumination wavelength.…”

Selective controlling transverse plasmon spectrum of pentagonal gold nanotube: from visible to near-infrared region

“…Gold nanotubes (AuNTs) can exhibit exceptional SERS and LSPR properties by modulating morphology as they have hollow interiors, high porosity, open tubular structures and more active sites for target molecules [9,10]. The nearinfrared region can provide deeper radiation penetration through tissue and blood, which makes AuNTs useful for photothermal therapy [11,12] and molecular imaging [13] with different techniques. Moreover, their versatility and unique properties have also generated much enthusiasm in catalysis [14][15][16], biosensors [17][18][19], protein transport [20] and other medicine fields [12].…”

“…The nearinfrared region can provide deeper radiation penetration through tissue and blood, which makes AuNTs useful for photothermal therapy [11,12] and molecular imaging [13] with different techniques. Moreover, their versatility and unique properties have also generated much enthusiasm in catalysis [14][15][16], biosensors [17][18][19], protein transport [20] and other medicine fields [12]. The research on the optical properties of AuNTs has been favored by many researchers.…”

“…The pentagonal AuNTs with near infrared absorption were synthesized by Ye and Azad based on the adjustment of silver nanowire template in the galvanic reaction [11][12][13]. The dominant peak in the wavelength between 600 and 1000 nm can be assigned to the transverse plasmon band of AuNTs.…”