scholarly journals Comprehensive insights into intracellular fate of WS2 nanosheets for enhanced photothermal therapeutic outcomes via exocytosis inhibition

Nanophotonics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 2331-2346 ◽  
Author(s):  
Na Kong ◽  
Li Ding ◽  
Xiaobin Zeng ◽  
Junqing Wang ◽  
Wenliang Li ◽  
...  

AbstractTwo-dimensional (2D) nanosheet (NS)-based photothermal agents (PTAs), such as transition-metal dichalcogenides, have shown immense potential for their use in cancer photothermal therapy (PTT). However, the nano-bio interaction study regarding these NS-based PTAs is still in its infancy. In this study, we used WS2-PEG NS-based PTA as an example to provide comprehensive insights into the experimental understanding of their fate in cancer cells. The data revealed that three different endocytosis pathways (macropinocytosis, clathrin-dependent, and caveolae-dependent endocytosis), autophagy-mediated lysosome accumulation, and exocytosis-induced excretion contribute to the integrated pathways of WS2-PEG NSs within cells. These pathways are consistent with our previous reports on MoS2-PEG NS-based drug delivery platform, indicating that the composition difference of 2D NSs with PEGylation may have little influence on their intercellular fate. Moreover, by blocking the revealed exocytosis pathway-mediated secretion of WS2 NSs in tumor cells, an effective approach is proposed to attain enhanced photothermal therapeutic outcomes with low doses of WS2 NSs and under a low power of a near-infrared (NIR) laser. We expect that the exocytosis inhibition strategy may be a universal one for 2D NSs to achieve combination cancer therapy. This study may also provide more experimental basis for the future development of 2D NS’s application in biomedicine (e.g. PTT).

2019 ◽  
Vol 10 ◽  
pp. 811-822 ◽  
Author(s):  
Tzuriel Levin ◽  
Hagit Sade ◽  
Rina Ben-Shabbat Binyamini ◽  
Maayan Pour ◽  
Iftach Nachman ◽  
...  

Nanostructures of transition-metal dichalcogenides (TMDC) have raised scientific interest in the last few decades. Tungsten disulfide (WS2) nanotubes and nanoparticles are among the most extensively studied members in this group, and are used for, e.g., polymer reinforcement, lubrication and electronic devices. Their biocompatibility and low toxicity make them suitable for medical and biological applications. One potential application is photothermal therapy (PTT), a method for the targeted treatment of cancer, in which a light-responsive material is irradiated with a laser in the near-infrared range. In the current article we present WS2 nanotubes functionalized with previously reported ceric ammonium nitrate–maghemite (CAN-mag) nanoparticles, used for PTT. Functionalization of the nanotubes with CAN-mag nanoparticles resulted in a magnetic nanocomposite. When tested in vitro with two types of cancer cells, the functionalized nanotubes showed a better PTT activity compared to non-functionalized nanotubes, as well as reduced aggregation and the ability to add a second-step functionality. This ability is demonstrated here with two polymers grafted onto the nanocomposite surface, and other functionalities could be additional cancer therapy agents for achieving increased therapeutic activity.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1557-1577 ◽  
Author(s):  
Xianguang Yang ◽  
Baojun Li

AbstractTransition metal dichalcogenides are two-dimensional semiconductors with strong in-plane covalent and weak out-of-plane interactions, resulting in exfoliation into monolayers with atomically thin thickness. This creates a new era for the exploration of two-dimensional physics and device applications. Among them, MoS2 is stable in air and easily available from molybdenite, showing tunable band-gaps in the visible and near-infrared waveband and strong light-matter interactions due to the planar exciton confinement effect. In the single-layer limit, monolayer MoS2 exhibits direct band-gaps and bound excitons, which are fundamentally intriguing for achieving the nanophotonic and optoelectronic applications. In this review, we start from the characterization of monolayer MoS2 in our group and understand the exciton modes, then explore thermal excitons and band renormalization in monolayer MoS2. For nanophotonic applications, the recent progress of nanoscale laser source, exciton-plasmon coupling, photoluminescence manipulation, and the MoS2 integration with nanowires or metasurfaces are overviewed. Because of the benefits brought by the unique electronic and mechanical properties, we also introduce the state of the art of the optoelectronic applications, including photoelectric memory, excitonic transistor, flexible photodetector, and solar cell. The critical applications focused on in this review indicate that MoS2 is a promising material for nanophotonics and optoelectronics.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Simon Dalgleish ◽  
Louisa Reissig ◽  
Yoshiaki Shuku ◽  
Giovanni Ligorio ◽  
Kunio Awaga ◽  
...  

Abstract Near-infrared sensitization of monolayer MoS2 is here achieved via the covalent attachment of a novel heteroleptic nickel bis-dithiolene complex into sulfur vacancies in the MoS2 structure. Photocurrent action spectroscopy of the sensitized films reveals a discreet contribution from the sensitizer dye centred around 1300 nm (0.95 eV), well below the bandgap of MoS2 (2.1 eV), corresponding to the excitation of the monoanionic dithiolene complex. A mechanism of conductivity enhancement is proposed based on a photo-induced flattening of the corrugated energy landscape present at sulfur vacancy defect sites within the MoS2 due to a dipole change within the dye molecule upon photoexcitation. This method of sensitization might be readily extended to other functional molecules that can impart a change to the dielectric environment at the MoS2 surface under stimulation, thereby extending the breadth of detector applications for MoS2 and other transition metal dichalcogenides.


2021 ◽  
Vol 9 (1) ◽  
pp. 148-156
Author(s):  
Haoyang Yi ◽  
Xinyue Zhou ◽  
Chaohui Zhou ◽  
Qingye Yang ◽  
Nengqin Jia

Ultrathin transition metal dichalcogenides (TMDs) seem to have a promising future in the field of theranostic agents due to their excellent near-infrared light absorption capacity and large specific surface area.


Author(s):  
Georgy Ermolaev ◽  
D. Grudinin ◽  
Y. Stebunov ◽  
K. Voronin ◽  
Vasyl Kravets ◽  
...  

Abstract Large optical anisotropy observed in a broad spectral range is of paramount importance for efficient light manipulation in countless devices. Although a giant anisotropy was recently observed in the mid-infrared wavelength range, for visible and near-infrared spectral intervals, the problem remains acute with the highest reported birefringence values of 0.8 in BaTiS3 and h-BN crystals. This inspired an intensive search for giant optical anisotropy among natural and artificial materials. Here, we demonstrate that layered transition metal dichalcogenides (TMDCs) provide an answer to this quest owing to their fundamental differences between intralayer strong covalent bonding and weak interlayer van der Walls interaction. To do this, we carried out a correlative far- and near-field characterization validated by first-principle calculations that reveals an unprecedented birefringence of 1.5 in the infrared and 3 in the visible light for MoS2. Our findings demonstrate that this outstanding anisotropy allows for tackling the diffraction limit enabling an avenue for on-chip next-generation photonics.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2699
Author(s):  
Mohammed Naffakh ◽  
Miriam Fernández ◽  
Peter S. Shuttleworth ◽  
Ana M. García ◽  
Diego A. Moreno

Layered transition-metal dichalcogenides (TMDCs) based on tungsten disulfide nanosheets (2D-WS2) were introduced via melt processing into poly(l-lactic acid) (PLLA) to generate PLLA/2D-WS2 nanocomposite materials. The effects of the 2D-WS2 on the morphology, crystallization, and biodegradation behavior of PLLA were investigated. In particular, the non-isothermal melt-crystallization of neat PLLA and PLLA/2D-WS2 nanocomposites were analyzed in detail by varying both the cooling rate and 2D-WS2 loading. The kinetic parameters of PLLA chain crystallization are successfully described using the Liu model. It was found that the PLLA crystallization rate was reduced with 2D-WS2 incorporation, while the crystallization mechanism and crystal structure of PLLA remained unchanged in spite of nanoparticle loading. This was due to the PLLA chains not being able to easily adsorb on the WS2 nanosheets, hindering crystal growth. In addition, from surface morphology analysis, it was observed that the addition of 2D-WS2 facilitated the enzymatic degradation of poorly biodegradable PLLA using a promising strain of actinobacteria, Lentzea waywayandensis. The identification of more suitable enzymes to break down PLLA nanocomposites will open up new avenues of investigation and development, and it will also lead to more environmentally friendly, safer, and economic routes for bioplastic waste management.


2021 ◽  
Author(s):  
Yong Lei ◽  
Xiao-Zhan Yang ◽  
Wenlin Feng

Abstract Van der Waals heterostructures based on the combination of 2D transition metal dichalcogenides (TMDCs) and conventional semiconductors offer new opportunities for the next generation of optoelectronics. In this work, the sulfurization of Mo film is used to synthesize vertically-aligned MoS2 nanofilm (V-MoS2) with wafer-size and layer controllability. The V-MoS2/n-Si heterojunction was fabricated by using a 20-nm thickness V-MoS2, and the self-powered broadband photodetectors covering from deep ultraviolet to near infrared is achieved. The device shows superior responsivity (5.06 mA/W), good photodetectivity (5.36×1011 Jones) and high on/off ratio Ion/Ioff (8.31 ×103 at 254 nm). Furthermore, the V-MoS2/n-Si heterojunction device presents a fast response speed with the rise time and fall time being 54.53 ms and 97.83 ms, respectiveely. The high photoelectric performances could be attributed to the high-quality heterojunction between the V-MoS2 and n-Si. These findings suggest that the V-MoS2/n-Si heterojunction has great potential applications in the deep ultraviolet-near infrared detection field, and might be used as a part of the construction of integrated optoelectronic systems.


Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7340
Author(s):  
Yoonsok Kim ◽  
Taeyoung Kim ◽  
Eun Kyu Kim

Two-dimensional (2D) materials, such as molybdenum disulfide (MoS2) of the transition metal dichalcogenides family, are widely investigated because of their outstanding electrical and optical properties. However, not much of the 2D materials research completed to date has covered large-area structures comprised of high-quality heterojunction diodes. We fabricated a large-area n-MoS2/p-Si heterojunction structure by sulfurization of MoOx film, which is thermally evaporated on p-type silicon substrate. The n-MoS2/p-Si structure possessed excellent diode characteristics such as ideality factor of 1.53 and rectification ratio in excess of 104. Photoresponsivity and detectivity of the diode showed up to 475 mA/W and 6.5 × 1011 Jones, respectively, in wavelength ranges from visible to near-infrared. The device appeared also the maximum external quantum efficiency of 72%. The rise and decay times of optical transient response were measured about 19.78 ms and 0.99 ms, respectively. These results suggest that the sulfurization process for large-area 2D heterojunction with MoS2 can be applicable to next-generation electronic and optoelectronic devices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
G. A. Ermolaev ◽  
D. V. Grudinin ◽  
Y. V. Stebunov ◽  
K. V. Voronin ◽  
V. G. Kravets ◽  
...  

AbstractLarge optical anisotropy observed in a broad spectral range is of paramount importance for efficient light manipulation in countless devices. Although a giant anisotropy has been recently observed in the mid-infrared wavelength range, for visible and near-infrared spectral intervals, the problem remains acute with the highest reported birefringence values of 0.8 in BaTiS3 and h-BN crystals. This issue inspired an intensive search for giant optical anisotropy among natural and artificial materials. Here, we demonstrate that layered transition metal dichalcogenides (TMDCs) provide an answer to this quest owing to their fundamental differences between intralayer strong covalent bonding and weak interlayer van der Waals interaction. To do this, we made correlative far- and near-field characterizations validated by first-principle calculations that reveal a huge birefringence of 1.5 in the infrared and 3 in the visible light for MoS2. Our findings demonstrate that this remarkable anisotropy allows for tackling the diffraction limit enabling an avenue for on-chip next-generation photonics.


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