Display omitted
•Provided a detailed introduction on THz metamaterials for spectrum modulation.•Summarized the different structures of THz metamaterials reported previously.•Introduced various ...special materials used in THz metamaterials.•Summarized the applications of THz metamaterials for spectrum modulation.
Metamaterials, an artificial electromagnetic (EM) material, have exhibited unique characteristics, enabling innovations in terahertz (THz) wavefront shaping, polarization modulation, surface wave manipulation, and spectrum modulation. In this review, we focus on the advancements in THz metamaterials for spectrum modulation, emphasizing their structural design, special materials, and applications. The review discusses various structural designs, including metal-dielectric composite structures, all-metal structures, and all-dielectric structures, each offering distinct advantages for THz applications. Key special materials such as graphene, vanadium dioxide (VO2), molybdenum disulfide (MoS2), and flexible materials are highlighted for their significant contributions to enhancing the performance and functionality of THz metamaterials. The applications of THz metamaterials in EM stealth and sensing are thoroughly introduced, with a particular focus on biosensing, pesticide detection, and other sensing applications. The review emphasizes the potential of THz metamaterials in developing highly sensitive and selective sensors, as well as efficient THz absorbers and filters. Future perspectives include the continuous development of novel materials, advanced fabrication technologies, and the integration of multifunctional capabilities to further expand the applications and efficiency of THz metamaterials. These advancements are expected to drive significant progress in THz technology, impacting fields such as medical diagnostics, environmental monitoring, food safety, wireless communication, and security.
Recently, plasmonic copper sulfide (Cu2–x S) nanocrystals (NCs) have attracted much attention as materials for photothermal therapy (PTT). Previous reports have correlated photoinduced cell death to ...the photothermal heat mechanism of these NCs, and no evidence of their photodynamic properties has been reported yet. Herein we have prepared physiologically stable near-infrared (NIR) plasmonic copper sulfide NCs and analyzed their photothermal and photodynamic properties, including therapeutic potential in cultured melanoma cells and a murine melanoma model. Interestingly, we observe that, besides a high PTT efficacy, these copper sulfide NCs additionally possess intrinsic NIR induced photodynamic activity, whereupon they generate high levels of reactive oxygen species. Furthermore, in vitro and in vivo acute toxic responses of copper sulfide NCs were also elicited. This study highlights a mechanism of NIR light induced cancer therapy, which could pave the way toward more effective nanotherapeutics.
Abstract Mesoporous silica nanoparticles (MSNs) have been proven to be effective drug carriers for oral delivery. However, little attention has been paid to their in vivo biodistribution and toxicity ...after oral administration. The effect of particle shape on their in vivo behavior is also unknown. In this study, we systematically studied the acute toxicity and biodistribution of three types of MSNs with aspect ratios (ARs) of 1, 1.75 and 5 after oral administration. The effect of particle shape as a key physicochemical parameter of MSNs was discussed. With the increase of AR, MSNs showed decreased in vivo biodegradation, systematic absorption and excretion, especially decreased liver distribution and urinal excretion. During the period of urinal excretion, MSNs induced a shape-dependent renal damage including hemorrhage, vascular congestion and renal tubular necrosis. These findings will enrich the knowledge to rationally engineer bionanomaterials, and bring new insights into nanotoxicity. From the Clinical Editor Advances in nanotechnology have resulted in improvement in drug delivery, of which mesoporous silica nanoparticles have been used as carriers for oral drugs. Nonetheless, studies on their absorption, distribution, metabolism, excretion (ADME) and toxicity still need to be performed. In this article, authors evaluated the effects of particle size and shape on in vivo behavior. The findings would shine light on future design of future drug delivery systems.
We design multifunctional CDDP-VPA@ZrMOF-Cys-PEG nanoparticles (CVZP NPs) based on the properties of valproic acid (VPA) that can downregulate the expression of vascular endothelial growth factor ...(VEGF) to reduce the drug resistance of tumor cells. In vivo experiments confirm that chemotherapy combined with microwave thermal therapy (MWTT) can significantly improve the therapeutic effect of cisplatin-resistant lung cancer.
Microwave sensitization nanoplatform, integrating multiple functional units for improving tumor selectivity, is of great significance for clinical tumor microwave treatment. Lanthanide europium metal ...organic framework (EuMOF) is expected to be a theranostic nanoplatform owing to its unique luminescent and microwave sensitization properties. However, it is difficult to be applied to complicated biological systems for EuMOF due to its rapid degradation induced by the solvent molecular and ionic environment. In this work, a luminescent EuMOF nanocomposite (EuMOF@ZIF/AP-PEG, named EZAP) was designed, which brought the multifunctional characteristics of microwave sensitization, fluorescence imaging and drug loading.
Lamellar EuMOF was synthesized by a hydrothermal method. Through the charge adsorption mechanism, the zeolite imidazole framework (ZIF) structure was intensively assembled on the surface of EuMOF to realize the protection. Then, through in-situ Apatinib drug loading and PEG modification, EZAP nanocomposite was finally obtained. Apatinib (AP) was a kind of chemotherapy drug approved by Food and Drug Administration for targeted therapy of tumors. PEG modification increased long-term circulation of EZAP nanocomposite. The physical and chemical structure and properties of EuMOF@ZIF (EZ) were systematically represented, indicating the successful synthesis of the nanocomposite. The toxic and side effects were negligible at a safe dose. The growth of human liver cancer cells and murine liver cancer cells in vitro was significantly inhibited, and the combined microwave-thermal therapy and chemotherapy in vivo achieved high anti-cancer efficacy. Moreover, EZAP nanocomposite possessed bright red fluorescence, which can be applied for tumor imaging in tumor-bearing mice in vivo.
Therefore, EZAP nanocomposite showed high microwave sensitization, excellent fluorescence properties and outstanding drug loading capacity, establishing a promising theranostic nanoplatform for tumor therapy and fluorescence imaging. This work proposes a unique strategy to design for the first time a multifunctional nanoplatform with lanthanide metal organic frameworks for biological applications in tumor therapy and diagnosis.
CdS@MoS
2
nanocomposites (NCs) were successfully prepared through a simple hydrothermal reaction. The morphology and structure of MoS
2
nanoflowers on CdS nanorods could be regulated by the change of ...the mass percentage of MoS
2
. The adsorption efficiency and photocatalytic activity of CdS@MoS
2
NCs were investigated by the adsorption and photocatalytic degradation of Rhodamine 6G. Interestingly, with the increase of MoS
2
ratio in the NCs, the adsorption effect of CdS@MoS
2
NCs increased significantly. These CdS@MoS
2
NCs showed a strong ability to process Rhodamine 6G, and could deal with up to 95% Rhodamine 6G within 1 h.
Graphical abstract
CdS@MoS
2
nanocomposites with tunable shape were synthesized through a hydrothermal method and possess high performance in the removal of Rhodamine 6G
In this article, a method for landslides identification based on polarimetric decomposition techniques and the Wishart classifier is presented. Several parameters of Cloude decomposition and ...Freeman-Durden decomposition are introduced to analyse the radar scattering mechanisms over landslides and their surroundings. By analysing the polarimetric characteristics of three typical landslides triggered by the 2008 Wenchuan earthquake, the result demonstrates that the dominant scattering mechanism of the landslides is the surface scattering component, and the scattering entropy is centred between 0.6 and 0.8. Besides, the result also indicates that the surroundings show the dominance of the volume scattering component, whereas their scattering entropy is almost similar to the landslides. According to the experimental analysis, two temporal SAR images are classified into nine categories, respectively, based on polarimetric decomposition techniques and the Wishart classifier. By comparing the surface scattering areas in the second image with the volume scattering areas in the first image, and combining the scattering entropy, the new slope failures are obtained using the change detection method. In addition, in order to reduce the errors introduced by the registration and noises, the identification map of new landslides is processed by the morphology algorithm. Finally, a field experiment is carried out to verify the existence of the new slope failures and thereby the result shows the validity of the proposed method.
Icosahedral Au-Pt alloy nanocrystals are prepared in porous hollow silica nanospheres via a hydrothermal method without using capping agents. These nanoparticles with unique shape and structure ...exhibit excellent catalytic activity and stability in Ullmann reactions.
A novel turn-on and turn-off sensor based on the fluorescence change of quantum dots (QDs) has been developed to detect the activity of butyrylcholinesterase (BChE). In the turn-on sensing system, we ...realized the detection of BChE with just one enzyme. A linear calibration plot of the activity of BChE was obtained in the wide amounts range from 10 to 1000U/L and the detection limit was 10U/L. In the turn-off sensing system, we realized the sensing of BChE with a wide linear relationship of 10–2000U/L which was much wider than many other detection methods. We also studied the application in serum sample detection. The BChE sensor shows great performances. Furthermore, the turn-on and turn-off sensing mechanisms were studied extensively. These results showed that our strategy would most probably be applicable in assembling diagnostic micro-device for realizing the rapid clinical analysis of BChE.
► Biosensor was composed of QDs and enzymes, without any complex processes. ► BChE detected by one step enzyme reaction for the first time. ► We studied the detection mechanisms of turn-on and turn-off detection system. ► We demonstrated the application in real serum samples. ► This work presents a feasible approach for detecting some kinds of substrate.
Nanoscale ZIF-8 had a high inhibitory effect on pyruvate kinase of M2.
Display omitted
Tumor cells usually show abnormally high glycolysis rate to maintain the dynamic balance of energy. The growth ...of tumor cells can be affected by inhibiting the activity of pyruvate kinase (especially M2-type isozyme, PKM2), the rate limiting enzyme of glycolysis. This is helpful to the treatment of tumor. Herein, metal organic frameworks (MOFs) were found to inhibit the activity of PKM2. Nanoscale ZIF-8 was synthesized by standing and ultrasonic method, respectively. The ZIF-8 has the performance of inhibiting PKM2. Further research showed that the inhibition ability was attributed to zinc ion in ZIF-8. Interestingly, the IC50 of ZIF-8 on PKM2 was one percent of that of zinc ion. This novel enzyme inhibitor is expected to be used in cancer therapy.
