Chemically exfoliated WS2 nanosheets efficiently inhibit amyloid β-peptide aggregation and can be used for photothermal treatment of Alzheimer＇s disease

Polymerization of amyloid-β peptide （Aβ） into amyloid fibrils is a critical step in the pathogenesis of Alzheimer＇s disease （AD）. Inhibition of Aβ aggregation and destabilization of preformed Aβ fibrils have promising effects against AD and have been used in clinic trials. Herein, we demonstrate, for the first time, the application of WS2 nanosheets, to not only effectively inhibit Aβ aggregation, but also dissociate preformed Aβ aggregates upon near infrared （NIR） irradiation. Additionally, the biocompatible WS2 nanosheets possess the ability to cross the blood-brain barrier （BBB） to overcome the limitations of most previously reported Aβ inhibitors. Through van der Waals and electrostatic interactions between Aβ40 and WS2, Aβ40 monomers can be selectively adsorbed on the surface of the nanosheet to inhibit the Aβ40 aggregation process. Intriguingly, the unique high NIR absorption property of WS2 enables amyloid aggregates to be dissolved upon NIR irradiation. These results will promote biological applications of WS2 and provide new insight into the design of multifunctional nanomaterials for AD treatment.

Lightweight and High-Performance Microwave Absorber Based on 2D WS2-RGO Heterostructures

Two-dimensional(2D)nanomaterials are categorized as a new class of microwave absorption(MA)materials owing to their high specific surface area and peculiar electronic properties.In this study,2D WS2-reduced graphene oxide(WS2-rGO)heterostructure nanosheets were synthesized via a facile hydrothermal process;moreover,their dielectric and MA properties were reported for the first time.Remarkably,the maximum reflection loss(RL)of the sample-wax composites containing 40 wt% WS2-rGO was-41.5 dB at a thickness of 2.7 mm;furthermore,the bandwidth where RL<-10 dB can reach up to 13.62 GHz(4.38-18 GHz).Synergistic mechanisms derived from the interfacial dielectric coupling and multiple-interface scattering after hybridization of WS2 with rGO were discussed to explain the drastically enhanced microwave absorption performance.The results indicate these lightweight WS2-rGO nanosheets to be potential materials for practical electromagnetic wave-absorbing applications.

Intimately coupled WS_(2) nanosheets in hierarchical hollow carbon nanospheres as the high-performance anode material for lithium-ion storage

Lithium-ion hybrid capacitors(LIHCs)have drawn extensive attention in fleld of energy storage.However,the absence of appropriate electrode materials with rapid kinetics restricted the overall performance of the capacitors.Herein,hierarchical N,P-codoped hollow car-bon nanospheres coupling with WS_(2) nanosheets(N,P-codoped HCNS/WS_(2)NSs)were fabricated for boosting lithium storage materials.Specially,the WS_(2) nanosheets with several layers embedded in the N,P-codoped hollow carbon nanospheres could not only enhance the conduc-tivity of composites,but also provide abundant channels for the rapid transfer of ions.As a result,as-prepared N,P-codoped HCNS/WS_(2) NSs demonstrated superior rate performance and long-term cycling stability.The reversible discharge capacity of 725.2 mAh·g^(-1) could be preserved after 1000 cycles at a current density of 1.0 A·g^(-1).Fur-thermore,LIHCs devices were assembled by using N,P-codoped HCNS/WS_(2) NSs and activated carbon(AC)as the cathode and anode,which exhibited high energy density of 166.7 Wh·kg^(-1) and power density of 5312.4 W·kg^(-1).Last but not least,the capacity almost had no obvious deterioration after 6000 cycles at a high current density of 10.0 A·g^(-1).

PEGylated WS_2 nanosheets for X-ray computed tomography imaging and photothermal therapy

WS2 nanosheets were prepared by the solvent-thermal method in the presence of n-butyl lithium, then the exfoliation under the condition of ultrasound. The formed WS2 nanosheets were conjugated with thiol-modified polyethylene glycol （PEG-SH） to improve the biocompatibility. The nanosheets （WS2- PEG） were able to inhibit the growth of a model HeLa cancer cell line in vitro due to the high photothermal conversion efficiency of ~35% irradiated by an 808 nm laser （1 W/cm^2）. As a proof of concept, WS2-PEG nanosheets with the better X-ray attenuation property than the clinical computed tomography （CT） contrast agent （lohexol） could be performed for CT imaging of the lymph vessel.