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Infectious diseases severely threaten human health, and traditional treatment techniques face multiple limitations. As an important component of immune cells, macrophages display unique biological properties, such as biocompatibility, immunocompatibility, targeting specificity, and immunoregulatory activity, and play a critical role in protecting the body against infections. The macrophage membrane-coated nanoparticles not only maintain the functions of the inner nanoparticles but also inherit the characteristics of macrophages, making them excellent tools for improving drug delivery and therapeutic implications in infectious diseases (IDs). In this review, we describe the characteristics and functions of macrophage membrane-coated nanoparticles and their advantages and challenges in ID therapy. We first summarize the pathological features of IDs, providing insight into how to fight them. Next, we focus on the classification, characteristics, and preparation of macrophage membrane-coated nanoparticles. Finally, we comprehensively describe the progress of macrophage membrane-coated nanoparticles in combating IDs, including drug delivery, inhibition and killing of pathogens, and immune modulation. At the end of this review, a look forward to the challenges of this aspect is presented., (© 2024 IOP Publishing Ltd.)

Titanium nanoparticles and pyrethroid pesticides are now being widely used in industrial, agriculture, and biomedical applications. In recent years, their health safety profiles have aroused concerns among health scientists. This study mainly explored the combined effects of titanium dioxide nanoparticles (TiO 2 NPs) and cypermethrin (CYP) on reproductive toxicity in male rats by gavage for 90 days. Thirty-two male Sprague-Dawley rats were assigned to four groups: the control group, the TiO 2 NPs group, the CYP group, and the combined titanium dioxide nanoparticles with cypermethrin (TiO 2 NPs + CYP) group. The results of biochemical analysis on testicular tissue homogenate showed that TiO 2 NPs and CYP mixtures decreased the activities of glutathione peroxidase (GSH-Px) and catalase (CAT) while increasing the activity of malondialdehyde (MDA) and lactate dehydrogenase (LDH). Meanwhile, the results of two-way factorial analysis of variance (ANOVA) showed a significant effect on GSH-Px, CAT, LDH, testicular cell apoptosis, and sperm quality in rats after exposure. Furthermore, the combined exposure group exhibited apoptosis of testicular cells and DNA damage. The results indicated that exposure to a mixture of TiO 2 NPs and CYP had adverse effects on the reproductive status of male rats., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Titanium dioxide nanoparticles (TiO 2 NPs) and cypermethrin (CPM) are widely used in various fields, and they can enter the environment in different ways. Combined exposure of TiO 2 NPs and CPM may increase the accumulation of pollutants in organisms and affect human health. This study was undertaken to evaluate the oxidative and inflammatory parameters associated with the combined exposure of TiO 2 NPs and CPM in rats. Twenty-four healthy male adult SD rats were randomly divided into four groups. The first group served as the control, while groups 2, 3, and 4 were treated with TiO 2 NPs (450 mg/m 3 ); CPM (6.67 mg/m 3 ) or combined exposure of TiO 2 NPs and CPM by inhalation for 90 days. We investigated the oxidative damage induced through combined exposure of TiO 2 NPs and CPM in rats by evaluating hematology of the rats and determining the blood biochemical index. Our results demonstrated that inhalation of TiO 2 NPs and CPM increased the levels of oxidative stress markers such as malondialdehyde and alkaline phosphatase in the serum of rats. These were accompanied by a decreased glutathione peroxidase and total superoxide dismutase levels. Furthermore, the level of glutathione peroxidase was further decreased while malondialdehyde was increased in the combined exposure of TiO 2 NPs and CPM. Interestingly, pathological sections showed that different degrees of tissue injury could be seen in the liver and lung tissues of each exposure group. In summary, the combined exposure of TiO 2 NPs and CPM can cause increased oxidative damage in rats and damage the tissue structure of the liver and lung.

Electrodynamic therapy (EDT) has recently emerged as an alternative approach for tumor therapy via the generation of ROS by platinum (Pt) nanoparticles under electric field. An interesting phenomenon observed during EDT is that the increased on-site concentration of chloride ions is highly beneficial for ROS generation and inhibition efficacy. Here, in this study, nanoclusters (KCC), consisting of potassium chloride (KCl) nanocrystals and amorphous calcium carbonate (CaCO 3 ), were synthesized and integrated with platinum nanoparticles (KCCP). In this system, KCC can dissolve and release calcium and chloride ions within tumor cells. The intracellular chloride ions considerably facilitated ROS generation by Pt nanoparticles under an electric field. More importantly, the excessive calcium ions and ROS formed a cycle of mutual promotion and self-amplification in cells, leading to agitated tumor inhibition, both in vitro and in vivo .

Poor tumour penetration became a major challenge for the use of nanoparticles in anticancer therapy. To further enhance the tumour penetration efficiency, we developed a tumour-microenvironment-responsive multistage drug delivery system which was formed layer by layer via electrostatic interaction with cationic drug-loaded nanoparticles, hyaluronidase (HAase) and iRGD-modified gelatin (G-iRGD). The drug-loaded nanoparticles were formed by self-assembling mPEG-PDPA-PG and encapsulation with epirubicin (EPI). Due to the protonation of tertiary amine groups of PDPA segment in acid environment, mPEG-PDPA-PG could enhance the lysosomal escape and the intracellular release of EPI. This NPs/HAase/G-iRGD delivery system showed great biocompatibility in vitro, confirmed by MTT method. In vitro spherical tumour model penetration and in vivo tumour permeability investigation showed HAase coated NPs-EPI (NPs-EPI/HAase) could significantly enhance its penetrating efficiency. The NPs-EPI/HAase could assist in breaking down the hyaluronic acid (HA), which was a key component of extracellular matrix and thereby improving mass transport within the solid tumours. The flow cytometry studies showed that G-iRGD coated NPs-EPI (NPs-EPI/G-iRGD) was more easily taken up by HepG2 cells than gelatin coated NPs-EPI (NPs-EPI/G), which revealed the active targeting ability of iRGD. The results proved that this NPs/HAase/G-iRGD delivery system showed promising potential in enhancing tumour penetration efficiency.

Silica-encapsulated luminescent lanthanide nanoparticles have shown great potential as biolabels for various time-gated luminescence bio-detections in recent years. The main problem of these nano-biolabels is their short excitation wavelengths within the UV region. In this work, a new type of silica-encapsulated luminescent europium nanoparticle, with a wide excitation range from UV to visible light in aqueous solutions, has been prepared using a conjugate of (3-isocyanatopropyl)triethoxysilane bound to a visible light-excited Eu(3+) complex, 2,6-bis(1',1',1',2',2',3',3'-heptafluoro-4',6'-hexanedion-6'-yl)-dibenzothiophene-Eu(3+)-2-(N,N-diethylanilin-4-yl)-4,6-bis(pyrazol-1-yl)-1,3,5-triazine (IPTES-BHHD-Eu(3+)-BPT conjugate), as a functionalized precursor. The nanoparticles, which are prepared by the copolymerization of the IPTES-BHHD-Eu(3+)-BPT conjugate, tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane in a water-in-oil reverse microemulsion consisting of Triton X-100, n-octanol, cyclohexane and water in the presence of aqueous ammonia, are monodisperse, spherical and uniform in size. Their diameter is 42 ± 3 nm and they are strongly luminescent with a wide excitation range from UV to ∼475 nm and a long luminescence lifetime of 346 μs. The nanoparticles were successfully used for streptavidin labeling and the time-gated luminescence imaging detection of two environmental pathogens, cryptosporidium muris and cryptosporidium parvium, in water samples. The results demonstrated the practical utility of the new nanoparticles as visible light-excited biolabels for time-gated luminescence bioassay applications.

The development of highly efficient non-noble metal catalysts for oxygen reduction reaction (ORR) is still a challenge in energy conversion and storage devices. Here we report a low-temperature strategy to synthesize ultrafine Fe and Fe 3 C nanoparticles anchored on nitrogen-doped mesoporous carbon (NMC). Iron precursors are synthesized through −60 °C liquid precipitation, then ultrafine and uniformly dispersed Fe and Fe 3 C nanoparticles are obtained by thermal treatment of the iron precursors. The prepared catalyst efficiently catalyzes 4-electron reduction of oxygen with half-wave potential (E 1/2) of 0.88 V in 0.1 M KOH, superior to the 20 wt% commercial Pt/C catalyst (E 1/2 = 0.86 V). The Fe/Fe 3 C-NMC electrocatalysts display remarkable stability and promising methanol tolerance. These new findings indicate potential new opportunities for exploring high ORR performance non-noble catalysts in electrochemical storage energy devices. [ABSTRACT FROM AUTHOR]

Abstract: Defective TiO2 attracted increasing attention due to its high photocatalytic activities. Herein, we report a facile and efficient method to fabricate gray defective TiO2 by vacuum annealing raw TiO2 materials with copper powders. The treated TiO2 nanoparticles exhibit significantly enhanced visible‐light‐photocatalytic performance with photo‐degradation rate increased to 400% as that of pristine commercial P25 under visible light. The performance enhancements can be attributed to the disordered structure, optimized optical and electronic properties of defective TiO2. In addition, this facile Cu reduction method provides an effective way to generate defective sites in other metal oxides for various potential applications. [ABSTRACT FROM AUTHOR]

A single fluorescent signal output often does not satisfy the detection accuracy requirements for bioactive compounds in biological systems. It is of great interest to develop a dual-channel turn-on fluorescence sensing system for self-validated detection. Herein, we report a self-quenching nanoparticle composed of dual two-photon dyes of naphthalimides, displaying almost no fluorescence at both channels, owing to aggregation-caused quenching (ACQ). A dual two-photon-channel fluorescent probe for GSH was further developed by inserting a disulfide bond between two naphthalimides. Upon treatment with GSH, the disulfide bond was cleaved, and two napthalimide fluorophores were separated, leading to turn-on fluorescence at both channels. This dual-two-photon-channel design strategy can be easily extended to other analytes, simply by changing the linker molecules, which creates new opportunities to accurately monitor various biological processes in living cells. [ABSTRACT FROM AUTHOR]