Latest ArticlesNear-infrared (NIR) light-triggered photothermal therapy (PTT) is a promising treatment strategy for treating cancer. The combination of nanotechnology and NIR has been widely applied. However, the therapeutic efficacy of the drug-delivery system depends on their ability to avoid phagocytosis of endothelial system, cross the biological barriers, prolong circulation life, localize and rapidly release the therapeutic at target sites. In this work, we designed a platelet membrane (PM)-camouflaged hollow mesoporous bismuth selenide nanoparticles (BS NPs) loading with indocyanine green (ICG) (PM@BS-ICG NPs) to achieve the above advantages. PM-coating has active tumor-targeting ability which could prevent drug leakage and provide drug long circulation, causing drug delivery systems to accumulate in tumor sites effectively. Moreover, as a type of the photothermal sensitizers, BS NPs are used as the inner cores to improve ICG stability and are served as scaffolds to enhance the hardness of this drug delivery system. For one hand, the thermal vibration of BS NPs under NIR laser irradiation causes tumor inhibition through hyperthermia. For another hand, this hyperthermia process could damage PM and let ICG rapid release from PM@BS-ICG NPs. The in vitro and in vivo results showed that this biomimetic nano-drug delivery system exhibits obvious antitumor activity which has good application prospect.
In this study, we report a new small molecule acceptor (named TT-4F) which uses 3, 6-dimethoxylthieno[3, 2-b]thiophene (TT) as the π-bridge. Addition of 0.05 weight ratio amount of TT-4F into the host binary blend of PTB7-Th:IEICO-4F, resulting in a ternary blend in a weight ratio of 1:1:0.05, enables increased open-circuit voltage (Voc), short-circuit current-density (Jsc), and fill-factor (FF) at the same time. Finally, 12.1% efficiency is obtained. Compared to the 3-(2-ethylhexyloxylthiophene) bridge on IEICO-4F, the additional methoxyl group on the TT-6 position is involved in the lowest unoccupied molecular orbital (LUMO) and the larger π-system on TT increases the electron-donating nature, both of which help to raise the LUMO level, one reason of the increased Voc. Upon addition of 0.05 TT-4F, the hole mobility is increased, the monomolecular recombination is reduced, and the charge dissociation and collection is enhanced. All of these contribute to the increased Jsc and FF.
Inflammation, as the pathophysiological response of body to harmful stimuli, leads to changes in cellular microenvironment. To research pH changes in lysosomes of macrophages during inflammation, we designed a FRET (Förster resonance energy transfer) based probe, BDP-RhB. The probe showed good lysosome targeting ability, wide response range of pH from 8.0 to 4.0 with significant ratio (I582/I518) change from 0.6 to 3.4, and good reversibility and sustainability. By applying BDP-RhB, we found a decrease of lysosomal pH of macrophages during inflammation.
Partially biobased polysilylethers (PSEs) are synthesized via dehydrocoupling polymerization catalyzed by an anionic iridium complex. Different types (AB type or AA and BB type) of monomers are suitable. Levulinic acid (LA) and succinic acid (SA) have been ranked within the top 10 chemicals derived from biomass. BB type monomers (diols) derived from LA and SA have been applied to the synthesis of PSEs. The polymerization reactions employ an air-stable anionic iridium complex bearing a functional bipyridonate ligand as catalyst. Moderate to high yields of polymers with number-average molecular weights (Mn) up to 4.38× 104 were obtained. A possible catalytic cycle via an Ir-H species is presented. Based on the results of kinetic experiments, apparent activation energy of polymerization in the temperature range of 0-10 ℃ is about 38.6 kJ/mol. The PSEs synthesized from AA and BB type monomers possess good thermal stability (T5=418 ℃ to 437 ℃) and low glass-transition temperature (Tg=-49.6 ℃).
Core-shell structured mesoporous silica nanoparticles have been firstly synthesized with the new template from L-leucine methyl ester hydrochloride (H-Leu-OMe HCl). LMSNs were characterized by transmission electron microscopy (TEM), nitrogen adsorption/desorption, and small-angle X-ray diffraction (SAXRD), demonstrating a well-ordered mesostructure. After loading doxorubicin hydrochloride (Dox) into pores, considerable loading capacity of 30.5% and favorable cumulative release amount were obtained. MTT assay suggested that Dox-loaded LMSNs demonstrated great promise to anti-tumor. The use of MSNs with the synthesized template, as a drug delivery carrier, will extend the pharmaceutical applications of silica materials.
Developing high efficiency and low cost electrocatalysts is critical for the enhancement of oxygen reduction reaction (ORR), which is the fundamental for the development and commercialization of renewable energy conversion technology. Herein, zinc-nitrogen-carbon (Zn-N-C) was prepared by using biomass resource chitosan via a facile carbon bath method. The obtained Zn-N-C delivered a high specific surface area (794.7 cm2 /g) together with pore volume (0.49 cm3 /g). During the electrochemical evaluation of oxygen reduction reaction (ORR), Zn-N-C displayed high activity for ORR with an onset potential E0=0.96 VRHE and a half wave potential E1/2=0.86 VRHE, which were more positive than those of the commercial 20 wt% Pt/C benchmark catalyst (E0=0.96 VRHE and E1/2=0.81 VRHE). In addition, the ZnN-C catalyst also had a better stability and methanol tolerance than those of the Pt/C catalyst.
Rhenium is one of important components for heterogeneous catalysts, which has been recently used for the catalytic reactions related to the production of biomass-derived chemicals such as deoxydehydration of vicinal OH groups, C-O hydrogenolysis, and hydrogenation of carboxylic acids, and so on. Suitable oxidation state of Re as a catalytic active species is strongly dependent on the catalytic reactions. The control of the oxidation state of Re species on the catalysts is crucial on the catalyst development.
In the past decade, nanoscale metal-organic frameworks (nMOFs) have drawn a great attention due to their high porosity, wide range of pore shapes, tunable frameworks and relatively low toxic. With the development of nanotechnology, many researchers studied the synthesis, characterization, functionalization and biotoxicity of nMOFs, and a more thorough understanding was developed about numerous nMOFs as promising platforms for biomedical applications. This review highlights the up-to-date progress of nMOFs related to their bio-applications such as drug delivery, bioimaging, biosensing and biocatalysis, and the common surface modification methods were classified into four categories:covalent post-synthetically modification, coordinative post-synthetically modification, noncovalent postsynthetically modification and modification on the external surface. At the same time, the challenges and perspectives of nMOFs were discussed as well.
Available onlineSilicon monoxide (SiO) is a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity (~2400 mAh/g), low working potential (< 0.5 V vs. Li+/Li), low cost, easy synthesis, nontoxicity, abundant natural source and smaller volume expansion than Si. However, low intrinsic electrical conductivity, low initial Coulombic efficiency (ICE) and inevitable volume expansion (~200%) impede its practical application. Here we fabricate SiO/wrinkled MXene composite (SiO-WM) by an electrostatic self-assembly method. Importantly, this method is simple, scalable and taking into account all the issues of SiO. As a result, the SiO-WM exhibits improved rate capability, cycling performance and ICE than bare SiO.
It is essential to develop a methanol gas sensor with high selectivity and low working temperature for human health and environmental monitoring. In this work, a blend of PEDOT:PSS and Ti3C2Tx with the mass ratio of 4:1 is used to fabricate a methanol gas sensor. It possesses a high response ratio of the largest response and the second largest response (5.54) and an enhanced response compared to pure PEDOT:PSS and pure Ti3C2Tx tested at room temperature. These findings may pave the way towards design of the MXenes based high-performance gas-sensing materials in the future.