Nano

Cancer remains a significant global health burden, claiming countless lives annually and incurring substantial direct and indirect economic costs. Despite advancements in therapeutic modalities, conventional cancer treatments, including chemotherapy, radiotherapy and surgery, are often hampered by limitations such as insufficient efficacy, dose-dependent side effects, high costs and patient tolerability. This has spurred extensive research into novel therapeutic approaches for this life-threatening disease. Metal nanoparticles (MNPs) have emerged as promising tools in cancer therapy due to their unique physicochemical properties spanning the past two decades. Owing to their size similarity to biological molecules, MNPs possess the inherent ability to penetrate cellular barriers, making them ideal carriers for targeted drug delivery. These multifunctional nanoplatforms offer distinct advantages over conventional therapeutics by enabling targeted delivery of anticancer agents to specific tumor sites, thereby enhancing therapeutic efficacy and minimizing systemic side effects. Photodynamic therapy and sonodynamic therapy represent particularly promising strategies that leverage MNPs for cancer treatment. This review delves into the potential applications of MNPs in modulating the tumor microenvironment, paving the way for the exploration of this vast and rapidly evolving field of nanomedicine.

Mesoporous silica, as a drug carrier, has become the new research focus in the field of nanodrug delivery system in recent years. In this study, Mn-doped mesoporous silicas are synthesized by template and in-situ doping method and physically characterized. The drug-loading performance of silica and its impact on drug release are studied. The Mn-doped mesoporous silicas show dendritic morphology (MDMS) with a loose wrinkle structure on the surface and a large number of pores. MDMS is used as a carrier to solve the problem of low water solubility of paclitaxel. In order to avoid leakage during drug transportation, the surface of Mn-doped mesoporous silica loaded with paclitaxel is coated with N-succinyl chitosan to construct a new type of nanodrug delivery system (MDMS-PTX-NSC). Compared to MDMS, MDMS-PTX-NSC shows an increase in particle size and smooth surface. The dissolution characteristics of manganese ions and swelling behavior of N-succinyl chitosan make MDMS-PTX-NSC delivery system exhibit a good pH-responsive release. And MDMS-PTX-NSC release curve can be well fitted by Ritger-Peppas equation. The cytotoxicity test shows that the MDMS-PTX-NSC has significant biocompatibility and enhanced cytotoxicity, which reveals that the MDMS-PTX-NSC is a promising nanodrug delivery system.

In this study, we report the synthesis of silver nanoparticles (AgNP’s) by reducing silver ions from a solution of silver nitrate with an aqueous extract from Azadirachta indica. Using silver ions as the catalyst, nanoparticles were formed in 8min without the use of toxic chemicals. As evidenced by UV-vis spectroscopy, a broad surface plasmon resonance spectrum at 225nm was detected, which indicates the colloidal solution of silver nanoparticles is stable and produces silver nanoparticles. As revealed by the fourier transform-infrared spectrometer (FTIR) analysis, the flower extract contained a variety of biomolecules that acted as capping and reducing agents for the synthesis of AgNPs. As determined by X-ray diffraction (XRD), silver nanoparticles displayed a crystalline structure and ranged in size from 18 to 39nm. In addition to these findings, transmission electron microscopy (TEM) images showed that the silver nanoparticles were spherical and rod-shaped, as confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX). A variety of pathogenic bacteria, such as Klebsiella pneumoniae, Escherichia coli, Bacillus subtilis and Staphylococcus aureus, were tested against AgNP’s antibacterial properties. A significant inhibition zone was observed for Escherichia coli when AgNPs were applied at different concentrations. Silver nanoparticles were shown to have antidiabetic effects through a diphtheria assay with inhibition rates ranging from 31.09% to 83.33% for concentrations of 50–250$\mu$g/mL. As researchers seek natural sources of compounds with potential health benefits, silver nanoparticles were also investigated for their antioxidant properties.

Supercapacitors require excellent cycling stability and rate capability for electrodes. The NiCo₂S₄ spinel structure has caught much attention for its high conductivity and high theoretical specific capacity. However, due to the lack of active sites, it has been restricted in supercapacitors. In this research, the NiCo₂S₄ nano-material with needle, sheet and porous network morphologies were prepared by the addition of different kinds of surfactants via a simple hydrothermal method. At 1mA/cm², capacitance of these NiCo₂S₄ nanomaterials is measured as 2.09F/cm², 3.22F/cm², and 4.42F/cm², respectively. It was found that the exposure ratio of (111) and (220) crystal facets also has an effect on electrochemical performance, and NiCo₂S₄ with I${}_{(111)}$/I${}_{(220)}$ of 3:1 showed better performance. Furthermore, NiCo₂S₄-PN//AC asymmetrical supercapacitor was assembled with NiCo₂S₄-PN serving as positive electrode and activated carbon (AC) as negative electrode. At a power density of 7.284mW/cm², energy density achieved was 0.625mWh/cm². Additionally, capacitance retention rate remained at 79.6% of initial capacitance after 1500 cycles. These outcomes are of great significance for developing more efficient, stable and reliable transition metal sulfide-based supercapacitors.

To enhance the poor sensing capabilities of traditional p-type metal oxide semiconductor sensors, a novel gas sensor was designed with Co₃O₄/CuO heterostructure modified by glutathione (GSH)-reduced gold (Au), which was characterized by different analyses. The experiments showed that the 0.5wt.% Au–Co₃O₄/CuO gas sensor exhibited excellent sensing performance with a response value of up to 28.3 for 3ppm NO₂ at a relatively low operating temperature ($100^{\circ }$C). Besides, it demonstrated a linear relationship between detection concentration and response value, displayed good selectivity for NO₂, showcased stability and exhibited repeatability. Moreover, the sensor revealed the ability to resist humidity at the optimal temperature. Finally, we proposed a gas sensing mechanism to explain the enhanced NO₂ detection performance of the sensor, attributed to the heterojunction structure between Co₃O₄/CuO and the catalytic properties of Au. This led to an increase in adsorbed oxygen, as confirmed by XPS characterization. Therefore, the 0.5wt.% Au–Co₃O₄/CuO ternary nanocomposite gas sensor is deemed to be a highly effective sensing material that can be utilized to detect NO₂ gas in real-life applications.

With the increasing quantity of intelligent and portable electric devices, a broad effective absorption bandwidth (EAB) microwave absorber (MWA) is required for shielding microwave (MW) interference. An MWA with a magnetic-dielectric synergistic effect is necessary for broadening the EAB of it. The amorphous/nanocrystalline Fe₈₅SiAl₆Cr₈ (FSAC) is a nanolevel high magnetic loss MWA, and the introduction of medium dielectric loss MWA nitrogen-doped carbonized kapok fiber (NCKF) with an appropriate proportion improved the impedance match and damping ability of the composite and broadened the EAB. The results revealed that the minimum reflection loss (RL${}_{min})$ of FSAC/NCKF was −22.5 dB at 16.8GHz with a thickness of 1.20mm, and the EAB was 4.91GHz with a thickness of 1.30mm. Besides, the EAB moved to the low-frequency range when the thickness increased. Meanwhile, the RL of the simulation and the experiment were remarkably similar. The strategy offers an approach for developing a MWA with broad EAB.

There is a strong interest in using green resources for synthesizing nanoparticles (NPs) of industrial and biomedical utility in a way to maintain desired material properties throughout use while not inducing any harmful effects. The use of various plant extracts as reducing, capping, or stabilizing agents is widely attempted in green nanotechnology. However, very little has been explored about incorporating plant extract blends into green NP synthesis routes. Here, we used the combination of tea and olive leaf extracts for the synthesis of silver NPs and evaluated the advantages it provided over both chemical and single-plant-mediated synthesis routes. Four different reducing agents (tannic acid, black tea leaves extract, olive leaves extract and their blend) were used to synthesize silver NPs (Ag NP) from silver nitrate (AgNO${}_3)$. The synthesized Ag NP was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), and ultraviolet-visible (US-Vis) spectroscopy. The antimicrobial properties of Ag NP were assessed against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus) using the colony-forming unit (CFU) assay and the minimum inhibitory concentration (MIC) assay. The cytotoxic potential of Ag NP on human colorectal adenocarcinoma (Caco-2) cells was assessed by the WST-1 assay. Results showed that Ag NP synthesized using plant extract mixtures had a primary particle size of 40nm and were very effective antibacterial agents, with the MIC values ranging from $5\mu$g/mL to 10$\mu$g/mL. While the particle size obtained in chemical synthesis was slightly lower, the resultant Ag NP did not serve as an effective antibacterial agents at low doses. Further understanding of how best to integrate extracts of different plants into green NP synthesis routes will enable wider and safer biomedical applications.