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Objective: We aimed to evaluate the efficacy of stem cell-derived exosomes for treating ischemic stroke and to screen for the optimal administration strategy. Methods: We searched PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases for relevant studies published from their inception to 31 December 2023. Conventional and network meta-analyses of the routes of administration, types, and immune compatibility of stem cell-derived exosomes were performed using the cerebral infarct volume (%) and modified neurological severity score (mNSS) as outcome indicators. Results: A total of 38 randomized controlled animal experiments were included. Conventional meta-analysis showed that compared with the negative control group: intravenous administration significantly reduced the cerebral infarct volume (%) and mNSS; intranasal administration significantly reduced the cerebral infarct volume (%); and intracerebral administration significantly reduced the mNSS. Adipose-derived mesenchymal stem cell-derived exosomes (ADSC-Exos), bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos), dental pulp stem cell-derived exosomes (DPSC-Exos) and neural stem cell-derived exosomes (NSC-Exos) significantly reduced the cerebral infarct volume (%) and mNSS; Endothelial progenitor cell-derived exosomes (EPC-Exos), embryonic stem cell-derived exosomes (ESC-Exos), induced pluripotent stem cell-derived exosomes (iPSC-Exos) and neural progenitor cell-derived exosomes (NPC-Exos) significantly reduced the cerebral infarct volume (%); Umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-Exos) significantly reduced the mNSS; and there was no significant difference between urogenital stem cell-derived exosomes (USC-Exos) and negative controls. Engineered modified exosomes had better efficacy than unmodified exosomes. Both allogeneic and xenogeneic stem cell-derived exosomes significantly reduced the cerebral infarct volume (%) and the mNSS. The network meta-analysis showed that intravenous administration was the best route of administration for reducing the cerebral infarct volume (%) and mNSS. Among the 10 types of stem cell-derived exosomes that were administered intravenously, BMSC-Exos were the best type for reducing the cerebral infarct volume (%) and the mNSS. Allogeneic exosomes had the best efficacy in reducing the cerebral infarct volume (%), whereas xenogeneic stem cell-derived exosomes had the best efficacy in reducing the mNSS. Conclusion: This meta-analysis, by integrating the available evidence, revealed that intravenous administration is the best route of administration, that BMSC-Exos are the best exosome type, that allogeneic exosomes have the best efficacy in reducing the cerebral infarct volume (%), and that xenogeneic exosomes have the best efficacy in reducing mNSS, which can provide options for preclinical studies. In the future, more high-quality randomized controlled animal experiments, especially direct comparative evidence, are needed to determine the optimal administration strategy for stem cell-derived exosomes for ischemic stroke. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display%5frecord.php?ID=CRD42024497333, PROSPERO, CRD42024497333 [ABSTRACT FROM AUTHOR]

Ion selective membranes are fundamental components of biological, energy, and computing systems. The fabrication of solid-state ultrathin membranes that can separate ions of similar size and the same charge with both high selectivity and permeance remains a challenge, however. Here, we present a method, utilizing the application of a remote electric field, to fabricate a high-density of (sub)nm pores in situ. This method takes advantage of the grain boundaries in few-layer polycrystalline MoS2 to enable the synthesis of nanoporous membranes with average pore size tunable from <1 to ~4 nm in diameter (with in situ pore expansion resolution of ~0.2 nm2 s−1). These membranes demonstrate selective transport of monovalent ions (K+, Na+ and Li+) as well as divalent ions (Mg2+ and Ca2+), outperforming existing two-dimensional material nanoporous membranes that display similar total permeance. We investigate the mechanism of selectivity using molecular dynamics simulations and unveil that the interactions between cations and the sluggish water confined to the pore, as well as cation-anion interactions, result in the different transport behaviors observed between ions. Atomically thin materials can form ionic sieves, in which certain species pass through the films, and others are prevented. Here, the authors synthesize nanoporous membranes using chemical vapor deposition and electrochemistry and reveal the mechanism behind the large ion selectivity they observe. [ABSTRACT FROM AUTHOR]

The rapid progress of the internet of things, cloud computing, and artificial intelligence has increased demand for high-performance computing. This demand has led to a focused exploration of novel nonvolatile memory (NVM) and brain-inspired neuromorphic-computing electronics, with research efforts directed at identifying materials compatible with complementary metal-oxide-semiconductor technology. Exploring fluorite-structured hafnium-zirconium oxide (HZO) mixed oxides has revealed promising ferroelectric (FE) and memristor characteristics, suggesting potential applications in emerging technologies. However, certain intrinsic properties of HZO-based FEs, such as high coercive fields (Ec) and polarization metastability, may pose challenges for commercial viability. Recent investigations of fluorite-structured HZO-based antiferroelectrics (AFEs) have highlighted their advantages, including lower energetic barriers, higher switching speeds, and a uniform phase distribution. These inherent benefits position fluorite-structured HZO-based AFEs as potential candidates within the NVM landscape. Furthermore, the accumulated polarization and spontaneous depolarization characteristics of fluorite-structured HZO-based AFEs make them worthy of potential integration into neuromorphic-computing because they resemble certain aspects of neuron behavior. Despite these positive aspects, a more thorough exploration and consideration are needed to address existing challenges. This review aims to present fluorite-structured HZO-based AFE materials and highlight the current challenges, possible applications, and future opportunities and can act as an update for recent developments in these intriguing materials and provide guidance for future researchers in the optimization and design of HZO-based AFE materials and devices for emerging NVM and neuromorphic-computing applications. [ABSTRACT FROM AUTHOR]

Flexible pressure sensors are indispensable in wearable electronics, human–machine interfaces and medical wisdom. Despite notable progress achieved in improving the sensitivity and the sensing range of piezoresistive sensors, long-term reliability of these sensors is easily interfered by weak binding fastness of conductive substances on substrates and environmental factors (such as humidity change, sweating, sunlight exposure and corrosive chemicals). Herein, a highly reliable piezoresistive sensor was developed based on a three-dimensional nonwoven coated with an organic/inorganic mixture. The addition of thermoplastic polyurethane into the coating mixture achieved firm immobilization of multi-walled carbon nanotubes and perfluorodecyltrichlorosilane on fiber surfaces. Subsequent sandwiching of the coated nonwoven in between a fabric interdigital electrode and a spunbond nonwoven endowed the resultant all-fabric piezoresistive sensor with a broad sensing range (0–118 kPa), high sensitivity (10.03 kPa−1), fast response/relaxation time (135/100 ms) and excellent reproducibility (≥2000 cycles), thus making it ideal to be used for real-time monitoring of human motions (including breath, pulse and joint bending). The sensor also showed good anti-fouling properties and high endurance against harsh environments (humidity change, sweating, sunlight exposure and corrosive chemicals), and its versatile application was demonstrated in wireless monitoring and spatial pressure recognition. Moreover, our sensor was fabricated using cost-effective materials and scalable approaches, making us believe in its great practical significance for commercialization. [ABSTRACT FROM AUTHOR]