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Nanopore protein (α-hemolysin) was used to detect sub-nanosized plastic particles leached from a PE-coated paper cup. These sub-nanosized plastic particles can increase the inflammation response of macrophages. [Display omitted] • Nanopore sensing detects sub-nanosized plastics in PE-coated paper cups. • Sub-nanosized plastic particles in paper cups were 1.8 times more detected in boiled water than in room temperature water. • Sub-nanosized and microplastic particles alter cell membrane dynamics. • Sub-nanosized plastic particles can induce inflammatory cell responses. In recent years, there has been growing global concern about environmental pollution, and the increasing use of plastic products has made microplastics a serious environmental pollutant worldwide. Accordingly, the development of microplastic detection methods and research on the harmful effects of microplastics on human health are being actively pursued. In this study, we detected particle leaching from PE-coated paper cups using label-free nanopore sensing to identify and quantify the presence of sub-nanosized plastic particles. Plastic particles leached from the paper cups were classified as < 1 nm and > 1 nm, and their interactions with artificial cell membranes and inflammatory responses in the cells were evaluated. The results demonstrated that in a commonly used paper cup, particles < 1.4 nm were present at a concentration of approximately 1.13 mM in hot water and 0.62 mM in room-temperature water. It was demonstrated that plastic particles < 1 nm could condense the artificial cell membrane, whereas particles > 1 nm could thicken the artificial cell membrane. Furthermore, both size ranges of particles leached from the paper cups triggered an inflammatory response in the cells, with the inflammatory response increasing in proportion to the concentration and treatment time. The detection and analysis revealed the presence of sub-nanosized plastic particles in PE-coated paper cups, which are commonly used in daily life. These particles pose health threats and contribute to environmental pollution. [ABSTRACT FROM AUTHOR]

Cholesterol is an essential component of cell membranes and serves as an important precursor of steroidal hormones and bile acids, but elevated levels of cholesterol and its oxidation products have been accepted as a risk factor for maintenance of health. The free and ester forms of cholesterol and fatty acids are the two major biological lipids. The aim of this hypothesis paper is to address the long-standing dogma that cholesterol is less susceptible to free radical peroxidation than polyunsaturated fatty acids (PUFAs). It has been observed that cholesterol is peroxidized much slower than PUFAs in plasma but that, contrary to expectations from chemical reactivity toward peroxyl radicals, cholesterol appears to be more readily autoxidized than linoleates in cell membranes. The levels of oxidation products of cholesterol and linoleates observed in humans support this notion. It is speculated that this discrepancy is ascribed to the fact that cholesterol and phospholipids bearing PUFAs are localized apart in raft and non-raft domains of cell membranes respectively and that the antioxidant vitamin E distributed predominantly in the non-raft domains cannot suppress the oxidation of cholesterol lying in raft domains which are relatively deficient in antioxidant. [Display omitted] • Cholesterol and phospholipid linoleates, the two major lipids, are oxidized by enzymatic and non-enzymatic mechanisms. • Cholesterol hydroperoxides are produced exclusively by free radical and singlet oxygen oxidation. • Different from plasma, cholesterol is more readily oxidized than linoleates in cell membranes. • Cholesterol lying in lipid rafts might not be well protected by a-tocopherol compared with PUFAs which lie in non-raft domains. [ABSTRACT FROM AUTHOR]

• Inverse problem of harmonic hole with surface tension. • Exact identification of the harmonic shape for remote shear loading. • Sufficient and necessary condition established for existence of such holes. Harmonic holes are designed to leave the mean stress as a constant in the surrounding material. When surface tension is imposed on the boundary of the holes, the existence of harmonic holes within an infinite elastic plane subjected to plane deformation was verified roughly in the literature by numerical techniques. However, a rigorous proof for the existence of harmonic holes has still been absent in the literature for any of the cases involving surface tension. In this paper, we perform an accurate analysis for the case of a single harmonic hole with constant surface tension in an infinite elastic plane under a uniform remote (in-plane) shear loading. We show that the harmonic hole exists strictly if and only if a certain combination of the surface tension, shear loading and the size of the hole does not exceed a critical value. Explicit exact formulae are obtained for describing the shape of the harmonic hole in both deformed and undeformed configurations. These formulae may find applications in the design of functional porous materials, in validating relevant numerical methods and in elucidating the preferred shapes of fluid-elastic membranes and cell membranes. [ABSTRACT FROM AUTHOR]

The ultrastructural features of the mature spermatozoon of Telorchis attenuatus (Digenea, Telorchiidae), an intestinal parasite of the red-eared turtle Trachemys scripta elegans (Testudines, Emydidae), are described using transmission electron microscopy (TEM). The mature spermatozoon of T. attenuatus is a filiform cell tapered at both ends and displays Bakhoum et al.'s type IV of digenean sperm cells. Spermatozoa of T. attenuatus have: (i) two axonemes of different lengths with the 9+'1' pattern of trepaxonematan Platyhelminthes, surrounded by a continuous submembranous layer of cortical microtubules at their anterior end, (ii) an external ornamentation of the plasma membrane following Quilichini et al.'s type 2 and associated with cortical microtubules, (iii) two bundles of parallel cortical microtubules with the maximum number situated in the anterior part of the sperm cell, (iv) spine-like bodies, (v) two mitochondria, and (vi) a large number of irregularly distributed glycogen granules. Furthermore, the morphology of the posterior spermatozoon extremity in T. attenuatus corresponds to the Quilichini et al.'s fasciolidean type. The results of the current study are especially compared to the existing information from other families within the superfamily Plagiorchioidea. • The ultrastructural organization of the spermatozoon in a species of the family Telorchiidae is studied for the first time. • Present paper increases the available database on sperm ultrastructure of digeneans. • The type of spermatozoon (type IV) is homogeneous in the Plagiorchioidea. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microporous Ti surface with aligned pores was synthesized successfully by electrochemical method. • Microporous Ti with aligned pore structure was controlled by electrochemical currents. • Microporous Ti promoted cell attachment and preferential growth on the aligned pores. This paper reports the synthesis of microporous Ti surfaces with aligned pores by applying a different current during electrochemical process for application in cell-surface interaction study and biomedical implants. As the microporous Ti surfaces were synthesized by current from (0.5–4)A, the microstructure of the Ti surfaces was shifted from a relative smooth to microporous one that was observed to have an aligned pore surface. Optical images showed that the micropore sizes in ∼(85.4–224.4)µm. The roughness of the microporous Ti was significantly higher than that of the Ti by a factor of approximately 5 to 7. Confocal laser scanning microscope showed excellent cell attachment and preferential growth on the microporous Ti with aligned channels after 72 h of culturing which could be important for cell-surface interactions study and biomedical implants. [ABSTRACT FROM AUTHOR]

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE) cause more than 100,000 deaths each year, which need efficient and non-resistant antibacterial agents. SAR analysis of 162 flavonoids from the plant in this paper suggested that lipophilic group at C-3 was crucial, and then 63 novel flavonoid derivatives were designed and total synthesized. Among them, the most promising K15 displayed potent bactericidal activity against clinically isolated MRSA and VRE (MICs = 0.25–1.00 μg/mL) with low toxicity and high membrane selectivity. Moreover, mechanism insights revealed that K15 avoided resistance by disrupting biofilm and targeting the membrane, while vancomycin caused 256 times resistance against MRSA, and ampicillin caused 16 times resistance against VRE by the same 20 generations inducing. K15 eliminated residual bacteria in mice skin MRSA-infected model (>99 %) and abdominal VRE-infected model (>92 %), which was superior to vancomycin and ampicillin. [Display omitted] • Guided synthesis of flavonoid derivatives from 162 natural flavonoids. • Amphiphilic flavonoid derivatives displayed broad-spectrum antibacterial activity. • K15 avoided resistance by damaging biofilm and targeting cell membranes. • K15 exhibited excellent therapeutic effect in vivo , superior to vancomycin and ampicillin. [ABSTRACT FROM AUTHOR]

Pancreatic β-cells are equipped with the molecular machinery allowing them to respond to high glucose levels in the form of electrical activity and Ca2+ oscillations. These oscillations drive insulin secretion. Two key ionic mechanisms involved in this response are the Store-Operated Current and the current through ATP-dependent K+ channels. Both currents have been shown to be regulated by the protein STIM1, but this dual regulation by STIM1 has not been studied before. In this paper, we use mathematical modelling to gain insight into the role of STIM1 in the β-cell response. We extended a previous β-cell model to include the dynamics of STIM1 and described the dependence of the ATP-dependent K+ current on STIM1. Our simulations suggest that the total concentration of STIM1 modifies the bursting frequency, the burst duration and the intracellular Ca2+ levels. These results are in good agreement with experimental reports, and the contribution of the studied currents to electrical activity and Ca2+ dynamics is discussed. The model predicts that in the absence of STIM1 the excitability of the plasma membrane increases and that the glucose threshold for electrical activity is shifted to lower concentrations. These computational predictions may be related to impaired insulin secretion under conditions of reduced STIM1 in the diabetic state. [ABSTRACT FROM AUTHOR]

We outline the interaction of two-dimensional nanomaterial and cell barriers and their potential applications in major diseases. This paper aims to provide insights into the subsequent development of new smart nanomaterials capable of transport within cells. [Display omitted] The cell membrane serves as a barrier against the free entry of foreign substances into the cell. Limited by factors such as solubility and targeting, it is difficult for some drugs to pass through the cell membrane barrier and exert the expected therapeutic effect. Two-dimensional nanomaterial (2D NM) has the advantages of high drug loading capacity, flexible modification, and multimodal combination therapy, making them a novel drug delivery vehicle for drug membrane attachment and intracellular transport. By modulating the surface properties of nanocarriers, it is capable of carrying drugs to break through the cell membrane barrier and achieve precise treatment. In this review, we review the classification of various common 2D NMs, the primary parameters affecting their adhesion to cell membranes, and the uptake mechanisms of intracellular transport. Furthermore, we discuss the therapeutic potential of 2D NMs for several major disorders. We anticipate this review will deepen researchers' understanding of the interaction of 2D NM drug carriers with cell membrane barriers, and provide insights for the subsequent development of novel intelligent nanomaterials capable of intracellular transport. [ABSTRACT FROM AUTHOR]