Turning the crank on a simple device filled with nanoparticles can remove serious pathogens from water in seconds, making it suitable for areas without electricity
Category: nanotechnology
Exosomes as critical mediators of cell-to-cell communication in cancer pathogenesis and their potential clinical application
Extracellular vesicles can be divided into 3 primary classes based on their size: exosomes (20–100 nm), microvesicles (100–1,000 nm) and apoptotic bodies (1–5 µm). Exosomes have been the major focus of extracellular vesicle research. The term “exosome” was coined by Trams et al. in 1981 for “exfoliated membrane vesicles with 5’-nucleotidase activity” (23). Exosomes are distinguished from apoptotic bodies and microvesicles in term of their size, origin (endosomal or cell membrane), markers and composition. With spherical to cup-shaped nanoparticles and specific surface molecular markers, such as CD9 and CD63, exosomes are formed by the inward budding of endosomal membranes, thereby containing a variety of proteins, mRNAs and miRNAs (24-27). In addition to various cell or tissue specific materials, exosomes also contain certain common proteins, including cytoplasmic proteins (Hsp70 and Hsp90), cytoskeletal proteins (tubulin and actin), membrane fusion proteins (Rab GTPases) and membrane-associated proteins (CD9, CD81 and CD63) (28-30). These proteins could be used as markers for exosome isolation and identification. However, exclusive protein markers for exosomes are currently unknown. The material contained in exosomes is well protected to prevent degradation. For example, the RNA in exosomes is more stable than that in plasma and is not easily degraded by RNases. Exosomal RNA can be stored at −20 °C for more than 5 years, and the concentration is not decreased when compared with freshly prepared samples (31).
The signals and mechanisms underlying exosome formation and cargo sorting into exosomes have not been thoroughly elucidated to date. The present evidence shows that at least Endosomal Sorting Complexes Required for Transport (ESCRT) class proteins, tetraspanin CD63, specific glycan modification, the p53/TSAP6 pathway, and/or lipid-dependent mechanisms are involved in the formation of intraluminal vesicles in extracellular vesicles (32). Moreover, Rab-dependent trafficking mechanisms (Rab11, Rab27 and Rab35) have roles in exosome exocytosis and secretion (33) (Figure 1). Recipient cells internalize the foreign exosomes via multiple processes, including phagocytosis, clathrin-mediated endocytosis, macropinocytosis, and receptor-mediated and direct fusion (34,35). The factors that determine which and how a molecule is included or excluded in exosomes is under debate. It is reported that as a component of the COP9 signalosome regulatory complex, JAB1/CSN5 is involved in sorting proteins into exosomes (36). The introduction of exosomes provides a new molecular platform to further study cell-cell interaction, specific targeted cell selection, mechanisms of internalization and the potential of serving as a drug delivery system (37,38). Moreover, exosomes have been found in nearly all human body fluids, such as blood plasma, saliva, cerebrospinal fluid, urine, malignant ascites and semen (39-42), thereby implying that exosomes can be exploited as useful tools for cancer diagnosis and predictive biomarkers for cancer prognosis. It is interesting that the rate of exosomal release and content is different between healthy cell exosomes and tumor-derived exosomes. Numerous studies, including in vitro and in vivo studies, as well as clinical analysis, demonstrate that the number of exosomes increases significantly in cancer cells compared to normal cells. The distinct content of exosomes between the two groups (most notably miRNAs) may have important clinical significance (43,44).
Sensor identifies sodium nitrite in drinks using laser-modified cork
A team of researchers from the Federal University of São Carlos (UFSCar) in the state of São Paulo, Brazil, has developed a sensor that can identify sodium nitrite (NaNO2) in various beverages, including mineral water, orange juice, and wine. This inorganic salt is used as a preservative and fixative to give products such as ham, bacon, and sausages their pink or red color. Depending on the amount, it can cause serious health problems by leading to the formation of nitrosamines, which are carcinogenic compounds.
“This risk motivated us to develop a simple, fast, and accessible way to detect the compound and ensure the quality and safety of liquid consumption,” says Bruno Campos Janegitz, head of the Laboratory of Sensors, Nanomedicine, and Nanostructured Materials (LSNano) at UFSCar. Janegitz coordinated the study, which was published in the journal Microchimica Acta.
“Detection [of NaNO2] in beverages, especially wines, is important for quality control, since its use is not legally permitted in Brazil and most countries,” the authors write in the article.
Ultrasensitive sensor maps magnetization textures in rhombohedral graphene
Graphene, which is comprised of a single layer of carbon atoms arranged in a hexagonal lattice, is a widely used material known for its advantageous electrical and mechanical properties. When graphene is stacked in a so-called rhombohedral (i.e., ABC) pattern, new electronic features are known to emerge, including a tunable band structure and a non-trivial topology.
Due to these emerging properties, electrons in rhombohedral graphene can behave as if they are being influenced by “hidden” magnetic fields, even if no magnetic field is applied to them. While this interesting effect is well-documented, closely studying how electrons organize themselves in the material, with their spins and valley states pointing in different directions, has so far proved challenging.
Researchers at Weizmann Institute of Science recently set out to further examine the local magnetization textures in rhombohedral graphene, using a nanoscale superconducting quantum interference device (nano-SQUID). Their paper, published in Nature Physics, offers new insight into the physical processes governing the correlated states previously observed in the material.
Curved nanosheets in anode help prevent battery capacity loss during fast charging
As electric vehicles (EVs) and smartphones increasingly demand rapid charging, concerns over shortened battery lifespan have grown. Addressing this challenge, a team of Korean researchers has developed a novel anode material that maintains high performance even with frequent fast charging.
A collaborative effort by Professor Seok Ju Kang in the School of Energy and Chemical Engineering at UNIST, Professor Sang Kyu Kwak of Korea University, and Dr. Seokhoon Ahn of the Korea Institute of Science and Technology (KIST) has resulted in a hybrid anode composed of graphite and organic nanomaterials. This innovative material effectively prevents capacity loss during repeated fast-charging cycles, promising longer-lasting batteries for various applications. The findings are published in Advanced Functional Materials.
During battery charging, lithium ions (Li-ions) move into the anode material, storing energy as Li atoms. Under rapid charging conditions, excess Li can form so-called “dead lithium” deposits on the surface, which cannot be reused. This buildup reduces capacity and accelerates battery degradation.
Atom-scale stencil patterns help nanoparticles take new shapes and learn new tricks
Inspired by an artist’s stencils, researchers have developed atomic-level precision patterning on nanoparticle surfaces, allowing them to “paint” gold nanoparticles with polymers to give them an array of new shapes and functions.
The “patchy nanoparticles” developed by University of Illinois Urbana-Champaign researchers and collaborators at the University of Michigan and Penn State University can be made in large batches, used for a variety of electronic, optical or biomedical applications, or used as building blocks for new complex materials and metamaterials.
Led by Qian Chen, an Illinois professor of materials science and engineering, the researchers report their findings in the journal Nature.
Acoustically activatable liposomes as a translational nanotechnology for site-targeted drug delivery and noninvasive neuromodulation
Purohit et al. incorporate sucrose into drug-loaded lipid nanoparticle (LNP) formulations, which shifts the acoustic impedance in a way that triggers drug release upon exposure to focused ultrasound (FUS). By using FUS to both transiently open the blood-brain-barrier and to release drugs from their LNPs, various drugs were delivered into the brains of mice.
Acoustically activatable nanocarriers made by incorporating 5% sucrose into liposomes release drug with low-intensity ultrasound, providing a readily clinically translatable system for both central and peripheral noninvasive neuromodulation.
Bioreducible Gene Delivery Platform that Promotes Intracellular Payload Release and Widespread Brain DispersionClick to copy article linkArticle link copied!
We here introduce a novel bioreducible polymer-based gene delivery platform enabling widespread transgene expression in multiple brain regions with therapeutic relevance following intracranial convection-enhanced delivery. Our bioreducible nanoparticles provide markedly enhanced gene delivery efficacy in vitro and in vivo compared to nonbiodegradable nanoparticles primarily due to the ability to release gene payloads preferentially inside cells. Remarkably, our platform exhibits competitive gene delivery efficacy in a neuron-rich brain region compared to a viral vector under previous and current clinical investigations with demonstrated positive outcomes. Thus, our platform may serve as an attractive alternative for the intracranial gene therapy of neurological disorders.
