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1.
Int J Biol Macromol ; : 135491, 2024 Sep 08.
Article in English | MEDLINE | ID: mdl-39255885

ABSTRACT

Functional hydrogel sensors have shown explosive growth in the health and medical fields. However, the uniform adhesion and the complicated polymerization process of hydrogels seriously hinder their further development. Herein, inspired by the layered structure of human skin, we prepare a Janus gel prepared by in-situ polymerization. Based on the lignin-Fe3+ dual catalytic system, the rapid polymerization of the gel was achieved at room temperature. By tailoring the mass ratio of lignin and Fe3+ in the precursor, the adhesion of the upper and bottom layers can be easily adjusted. In addition, hydrophobic association is introduced into the upper layer to improve the gel's mechanical properties. The obtained asymmetric bilayer gel has a significant difference in adhesion (7 times), and exhibits excellent mechanical properties in the elongation at break (1437 %) and the breaking strength (463.2 kPa). Moreover, the bilayer gel also has good freezing and UV resistance. We use the bilayer gel as a wearable strain sensor, which shows a wide strain detection range of 0-800 % (maximum gauge factor = 5.3). The proposed simple strategy avoids UV irradiation and heating processes, which provides a new idea for the rapid polymerization of multifunctional Janus hydrogels with adjustable performances.

2.
Chem Phys Lipids ; 263: 105421, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39067642

ABSTRACT

This study explores the impact of the antimicrobial peptide magainin 2 (Mag2) on lipid bilayers with varying compositions. We employed high-resolution atomic force microscopy (AFM) to reveal a dynamic spectrum of structural changes induced by Mag2. Our AFM imaging unveiled distinct structural alterations in zwitterionic POPC bilayers upon Mag2 exposure, notably the formation of nanoscale depressions within the bilayer surface, which we term as "surface pores" to differentiate them from transmembrane pores. These surface pores are characterized by a limited depth that does not appear to fully traverse the bilayer and reach the opposing leaflet. Additionally, our AFM-based force spectroscopy investigation on POPC bilayers revealed a reduction in bilayer puncture force (FP) and Young's modulus (E) upon Mag2 interaction, indicating a weakening of bilayer stability and increased flexibility, which may facilitate peptide insertion. The inclusion of anionic POPG into POPC bilayers elucidated its modulatory effects on Mag2 activity, highlighting the role of lipid composition in peptide-bilayer interactions. In contrast to surface pores, Mag2 treatment of E. coli total lipid extract bilayers resulted in increased surface roughness, which we describe as a fluctuation-like morphology. We speculate that the weaker cohesive interactions between heterogeneous lipids in E. coli bilayers may render them more susceptible to Mag2-induced perturbations. This could lead to widespread disruptions manifested as surface fluctuations throughout the bilayer, rather than the formation of well-defined pores. Together, our findings of nanoscale bilayer perturbations provide useful insights into the molecular mechanisms governing Mag2-membrane interactions.


Subject(s)
Lipid Bilayers , Magainins , Microscopy, Atomic Force , Phosphatidylcholines , Lipid Bilayers/chemistry , Magainins/chemistry , Phosphatidylcholines/chemistry , Phosphatidylglycerols/chemistry , Spectrum Analysis
3.
Biochim Biophys Acta Biomembr ; 1866(7): 184373, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39047857

ABSTRACT

Transmembrane peptides play important roles in many biological processes by interacting with lipid membranes. This study investigates how the transmembrane domain of the influenza A virus M2 protein, M2TM, affects the structure and mechanics of model lipid bilayers. Atomic force microscopy (AFM) imaging revealed small decreases in bilayer thickness with increasing peptide concentrations. AFM-based force spectroscopy experiments complemented by theoretical model analysis demonstrated significant decreases in bilayer's Young's modulus (E) and lateral area compressibility modulus (KA). This suggests that M2TM disrupts the cohesive interactions between neighboring lipid molecules, leading to a decrease in both the bilayer's resistance to indentation (E) and its ability to resist lateral compression/expansion (KA). The large decreases in bilayer elastic parameters (i.e., E and KA) contrast with small changes in bilayer thickness, implying that bilayer mechanics are not solely dictated by bilayer thickness in the presence of transmembrane peptides. The observed significant reduction in bilayer mechanical properties suggests a softening effect on the bilayer, potentially facilitating membrane curvature generation, a crucial step for M2-mediated viral budding. In parallel, our Raman spectroscopy revealed small but statistically significant changes in hydrocarbon chain vibrational dynamics, indicative of minor disordering in lipid chain conformation. Our findings provide useful insights into the complex interplay between transmembrane peptides and lipid bilayers, highlighting the significance of peptide-lipid interactions in modulating membrane structure, mechanics, and molecular dynamics.


Subject(s)
Influenza A virus , Lipid Bilayers , Microscopy, Atomic Force , Viral Matrix Proteins , Lipid Bilayers/chemistry , Lipid Bilayers/metabolism , Viral Matrix Proteins/chemistry , Viral Matrix Proteins/metabolism , Influenza A virus/chemistry , Influenza A virus/metabolism , Peptides/chemistry , Protein Domains , Elastic Modulus , Viroporin Proteins
4.
Methods Enzymol ; 700: 189-216, 2024.
Article in English | MEDLINE | ID: mdl-38971600

ABSTRACT

We describe a method for investigating lateral membrane heterogeneity using cryogenic electron microscopy (cryo-EM) images of liposomes. The method takes advantage of differences in the thickness and molecular density of ordered and disordered phases that are resolvable in phase contrast cryo-EM. Compared to biophysical techniques like FRET or neutron scattering that yield ensemble-averaged information, cryo-EM provides direct visualization of individual vesicles and can therefore reveal variability that would otherwise be obscured by averaging. Moreover, because the contrast mechanism involves inherent properties of the lipid phases themselves, no extrinsic probes are required. We explain and discuss various complementary analyses of spatially resolved thickness and intensity measurements that enable an assessment of the membrane's phase state. The method opens a window to nanodomain structure in synthetic and biological membranes that should lead to an improved understanding of lipid raft phenomena.


Subject(s)
Cryoelectron Microscopy , Liposomes , Cryoelectron Microscopy/methods , Liposomes/chemistry , Lipid Bilayers/chemistry , Membrane Microdomains/ultrastructure , Membrane Microdomains/chemistry , Membrane Microdomains/metabolism , Membrane Lipids/chemistry , Phase Separation
5.
Biosens Bioelectron ; 254: 116223, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38518561

ABSTRACT

Pursuing accurate, swift, and durable pH sensors is important across numerous fields, encompassing healthcare, environmental surveillance, and agriculture. In particular, the emphasis on real-time pH monitoring during cell cultivation has become increasingly pronounced in the current scientific environment-a crucial element being diligently researched to ensure optimal cell production. Both polyaniline (PANi) and iridium oxide (IrOx) show their worth in pH sensing, yet they come with challenges. Single-PANi-layered pH sensors often grapple with diminished sensitivity and lagging responses, while electrodeposited IrOx structures exhibit poor adhesion, leading to their separation from metallic substrates-a trait undesirable for a consistently stable, long-term pH sensor. This paper introduces a bi-layered PANi-IrOx pH sensor, strategically leveraging the advantages of both materials. The results presented here underscore the sensitivity enhancement of binary-phased framework, faster response time, and more robust structure than prior work. Through this synergistic strategy, we demonstrate the potential of integrating different phases to overcome the inherent constraints of individual materials, setting the stage for advanced pH-sensing solutions.


Subject(s)
Biosensing Techniques , Biosensing Techniques/methods , Cell Culture Techniques , Aniline Compounds/chemistry , Hydrogen-Ion Concentration
6.
Eur Biophys J ; 53(1-2): 57-67, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38172352

ABSTRACT

The human immunodeficiency virus type 1 (HIV-1) matrix protein contains a highly basic region, MA-HBR, crucial for various stages of viral replication. To elucidate the interactions between the polybasic peptide MA-HBR and lipid bilayers, we employed liquid-based atomic force microscopy (AFM) imaging and force spectroscopy on lipid bilayers of differing compositions. In 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayers, AFM imaging revealed the formation of annulus-shaped protrusions upon exposure to the polybasic peptide, accompanied by distinctive mechanical responses characterized by enhanced bilayer puncture forces. Importantly, our AFM-based force spectroscopy measurements unveiled that MA-HBR induces interleaflet decoupling within the cohesive bilayer organization. This is evidenced by a force discontinuity observed within the bilayer's elastic deformation regime. In POPC/cholesterol bilayers, MA-HBR caused similar yet smaller annular protrusions, demonstrating an intriguing interplay with cholesterol-rich membranes. In contrast, in bilayers containing anionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) lipids, MA-HBR induced unique annular protrusions, granular nanoparticles, and nanotubules, showcasing its distinctive effects in anionic lipid-enriched environments. Notably, our force spectroscopy data revealed that anionic POPS lipids weakened interleaflet adhesion within the bilayer, resulting in interleaflet decoupling, which potentially contributes to the specific bilayer perturbations induced by MA-HBR. Collectively, our findings highlight the remarkable variations in how the polybasic peptide, MA-HBR, interacts with lipid bilayers of differing compositions, shedding light on its role in host membrane restructuring during HIV-1 infection.


Subject(s)
HIV-1 , Lipid Bilayers , Humans , Lipid Bilayers/chemistry , Microscopy, Atomic Force/methods , Phosphatidylcholines/chemistry , Spectrum Analysis , Peptides , Cholesterol
7.
Adv Mater ; 36(1): e2306653, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37696052

ABSTRACT

Hygroscopic salt-based composite sorbents are considered ideal candidates for solar-driven atmospheric water harvesting. The primary challenge for the sorbents lies in exposing more hygroscopically active sites to the surrounding air while preventing salt leakage. Herein, a hierarchically structured scaffold is constructed by integrating cellulose nanofiber and lithium chloride (LiCl) as building blocks through 3D printing combined with freeze-drying. The milli/micrometer multiscale pores can effectively confine LiCl and simultaneously provide a more exposed active area for water sorption and release, accelerating both water sorption and evaporation kinetics of the 3D printed structure. Compared to a conventional freeze-dried aerogel, the 3D printed scaffold exhibits a water sorption rate that is increased 1.6-fold, along with a more than 2.4-fold greater water release rate. An array of bilayer scaffolds is demonstrated, which can produce 0.63 g g-1 day-1 of water outdoors under natural sunlight. This article provides a sustainable strategy for collecting freshwater from the atmosphere.

8.
Nanotechnology ; 35(12)2024 Jan 04.
Article in English | MEDLINE | ID: mdl-38086071

ABSTRACT

At low temperatures about 230 °C, bilayer InGaZnO/In2O3thin film transistors (TFTs) were prepared by a solution process with lightwave annealing. The InGaZnO/In2O3bilayer TFTs with SiO2as dielectric layer show high electrical performances, such as a mobility of 7.63 cm2V-1s-1, a threshold voltage (Vth) of 3.8 V, and an on/off ratio higher than 107, which are superior to single-layer InGaZnO TFTs or In2O3TFTs. Moreover, bilayer InGaZnO/In2O3TFTs demonstrated a great bias stability enhancement due to the introduction of top InGaZnO film act as a passivation layer, which could prevent the interaction of ambient air with the bottom In2O3layer. By using high dielectric constant AlOxfilm, the InGaZnO/In2O3TFTs exhibit an improved mobility of 47.7 cm2V-1s-1. The excellent electrical performance of the solution-based InGaZnO/In2O3TFTs shows great application potential for low-cost flexible printed electronics.

9.
Biochim Biophys Acta Biomembr ; 1866(2): 184261, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38101595

ABSTRACT

Novel terminally perfluorobutyl group-containing ether-linked phosphatidylcholines with different alkyl chain lengths (di-O-F4-Cn-PCs, n = 14,16 and 18) were developed as possible materials for stable liposomes aiming at applications of structural and functional analyses of membrane proteins. Differential scanning calorimetric investigations of the thermotropic transition of hydrated di-O-F4-Cn-PC bilayers demonstrated that the transition temperature of every di-O-F4-Cn-PC decreases by ~20 °C compared to their corresponding non-fluorinated PCs, di-O-Cn-PCs. With the elongation of the hydrophobic chain, on the other hand, the transition enthalpy (ΔH) and entropy (ΔS) increased in a linear manner. Comparison of ΔH and ΔS values against the net hydrocarbon chain length between di-O-F4-Cn-PCs and di-O-Cn-PCs strongly suggests that in the thermotropic transition of the di-O-F4-Cn-PC membrane, the perfluorobutyl segments undergo very limited structural changes; therefore, the hydrocarbon segments are mainly responsible for the phase transition.


Subject(s)
Lipid Bilayers , Phosphatidylcholines , Phosphatidylcholines/chemistry , Lipid Bilayers/chemistry , Ether , Thermodynamics , Ethers , Ethyl Ethers , Hydrocarbons
10.
Gels ; 9(7)2023 Jul 10.
Article in English | MEDLINE | ID: mdl-37504442

ABSTRACT

pH-responsive hydrogels are recognized as versatile sensors and actuators due to their unique time-dependent properties. Specifically, pH-sensitive hydrogel-based bilayers exhibit remarkable bending capabilities when exposed to pH-triggered swelling. This study introduces a semi-analytical technique that combines non-linear solid mechanics with ionic species transport to investigate the bending behavior of such bilayers. The technique is validated through numerical simulations, exploring the influence of kinetic and geometric properties on bilayer behavior. The results highlight the significance of the interfacial region, particularly in configurations with lower hydrogel geometric ratios, which are susceptible to rupture. The study also uncovers the benefits of a lower hydrogel layer ratio in improving the swelling rate and final deflection, with a stronger effect observed in the presence of a buffer solution. Additionally, the compressibility of the elastomer contributes to the durability of the final bent shape. These findings enhance our understanding of pH-sensitive hydrogel-based bilayers and offer valuable insights for their design and optimization in diverse applications.

11.
Nanomaterials (Basel) ; 13(12)2023 Jun 13.
Article in English | MEDLINE | ID: mdl-37368281

ABSTRACT

Recently, resistive random access memory (RRAM) has been an outstanding candidate among various emerging nonvolatile memories for high-density storage and in-memory computing applications. However, traditional RRAM, which accommodates two states depending on applied voltage, cannot meet the high density requirement in the era of big data. Many research groups have demonstrated that RRAM possesses the potential for multi-level cells, which would overcome demands related to mass storage. Among numerous semiconductor materials, gallium oxide (a fourth-generation semiconductor material) is applied in the fields of optoelectronics, high-power resistive switching devices, and so on, due to its excellent transparent material properties and wide bandgap. In this study, we successfully demonstrate that Al/graphene oxide (GO)/Ga2O3/ITO RRAM has the potential to achieve two-bit storage. Compared to its single-layer counterpart, the bilayer structure has excellent electrical properties and stable reliability. The endurance characteristics could be enhanced above 100 switching cycles with an ON/OFF ratio of over 103. Moreover, the filament models are also described in this thesis to clarify the transport mechanisms.

12.
Front Bioeng Biotechnol ; 11: 1103435, 2023.
Article in English | MEDLINE | ID: mdl-36937756

ABSTRACT

Introduction: The porcine nerve-derived extracellular matrix (ECM) fabricated as films has good performance in peripheral nerve regeneration. However, when constructed as conduits to bridge nerve defects, ECM lacks sufficient mechanical strength. Methods: In this study, a novel electrospun bilayer-structured nerve conduit (BNC) with outer poly (L-lactic acid-co-ε-caprolactone) (PLA-PCL) and inner ECM was fabricated for nerve regeneration. The composition, structure, and mechanical strength of BNC were characterized. Then BNC biosafety was evaluated by cytotoxicity, subcutaneous implantation, and cell affinity tests. Furthermore, BNC was used to bridge 10-mm rat sciatic nerve defect, and nerve functional recovery was assessed by walking track, electrophysiology, and histomorphology analyses. Results: Our results demonstrate that BNC has a network of nanofibers and retains some bioactive molecules, including collagen I, collagen IV, laminin, fibronectin, glycosaminoglycans, nerve growth factor, and brain-derived neurotrophic factor. Biomechanical analysis proves that PLA-PCL improves the BNC mechanical properties, compared with single ECM conduit (ENC). The functional evaluation of in vivo results indicated that BNC is more effective in nerve regeneration than PLA-PCL conduit or ENC. Discussion: In conclusion, BNC not only retains the good biocompatibility and bioactivity of ECM, but also obtains the appropriate mechanical strength from PLA-PCL, which has great potential for clinical repair of nerve defects.

13.
Adv Sci (Weinh) ; 10(11): e2206925, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36793107

ABSTRACT

High indoor humidity/temperature pose serious public health threat and hinder industrial productivity, thus adversely impairing the wellness and economy of the entire society. Traditional air conditioning systems for dehumidification and cooling involve significant energy consumption and have accelerated the greenhouse effect. Here, this work demonstrates an asymmetric bilayer cellulose-based fabric that enables solar-driven continuous indoor dehumidification, transpiration-driven power generation, and passive radiative cooling using the same textile without any energy input. The multimode fabric (ABMTF) consists of a cellulose moisture absorption-evaporation layer (ADF) and a cellulose acetate (CA) radiation layer. The ABMTF exhibits a high moisture absorption capacity and water evaporation rate, which quickly reduces the indoor relative humidity (RH) to a comfortable level (40-60% RH) under 1 sun illumination. The evaporation-driven continuous capillary flow generates a maximum open-circuit voltage (Voc ) of 0.82 V, and a power density (P) up to 1.13 µW cm-3 . When a CA layer with high solar reflection and mid-infrared (mid-IR) emissivity faces outward, it realizes subambient cooling of ≈12 °C with average cooling power of ≈106 W m-2 at midday under radiation of 900 W m-2 . This work brings a new perspective to develop the next-generation, high performance environmentally friendly materials for sustainable moisture/thermal management and self-powered applications.

14.
ACS Appl Mater Interfaces ; 15(1): 1105-1114, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36584331

ABSTRACT

The great development potential of polymer dielectric capacitors in harsh environments urgently requires enhancing capacitive performance at high temperatures. However, the exponentially increased conduction loss at high temperature and high field results in a drastic drop in energy density and charge-discharge efficiency. Here, a bilayer-structured polyimide (PI) composite film containing a wide-band gap inorganic layer as a charge blocking layer is designed. The inorganic layer improves the charge trapping ability and regulates the charge mobility at the electrode/dielectric interface. The charge injection mechanism in the interface-optimized PI/boron nitride nanosheet (BNNS) composite films is investigated by finite element simulation, and the effect of the BNNS layer on high temperature conduction is further understood. An appropriate thickness of the charge blocking layer establishes an effective energy barrier. Therefore, the composite films exhibit significantly suppressed conduction loss and excellent capacitive performance at a high temperature. A high energy density of 4.37 J cm-3 with efficiency of 92% is obtained at 200 °C and 500 MV m-1, which is superior to reported high-temperature dielectric polymers and their composite films. This work provides a promising approach to improve the energy storage performance of polymer materials at high temperatures.

15.
Biophysica ; 3(4): 582-597, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38737720

ABSTRACT

Understanding the membrane interactions of the N-terminal 17 residues of the huntingtin protein (HttN) is essential for unraveling its role in cellular processes and its impact on huntingtin misfolding. In this study, we used atomic force microscopy (AFM) to examine the effects of lipid specificity in mediating bilayer perturbations induced by HttN. Across various lipid environments, the peptide consistently induced bilayer disruptions in the form of holes. Notably, our results unveiled that cholesterol enhanced bilayer perturbation induced by HttN, while phosphatidylethanolamine (PE) lipids suppressed hole formation. Furthermore, anionic phosphatidylglycerol (PG) and cardiolipin lipids, along with cholesterol at high concentrations, promoted the formation of double-bilayer patches. This unique structure suggests that the synergy among HttN, anionic lipids, and cholesterol can enhance bilayer fusion, potentially by facilitating lipid intermixing between adjacent bilayers. Additionally, our AFM-based force spectroscopy revealed that HttN enhanced the mechanical stability of lipid bilayers, as evidenced by an elevated bilayer puncture force. These findings illuminate the complex interplay between HttN and lipid membranes and provide useful insights into the role of lipid composition in modulating membrane interactions with the huntingtin protein.

16.
Clin Biomech (Bristol, Avon) ; 99: 105743, 2022 10.
Article in English | MEDLINE | ID: mdl-36099706

ABSTRACT

BACKGROUND: This paper addresses the question of the in vivo measurement of breast tissue stiffness, which has been poorly adressed until now, except for elastography imaging which has shown promising results but which is still difficult for clinicians to use on a day-to-day basis. Estimating subject-specific tissue stiffness is indeed a critical area of research due to the development of a large number of Finite Element (FE) breast models for various medical applications. METHODS: This paper proposes to use an original aspiration device, put into contact with breast surface, and to estimate tissue stiffness using an inverse analysis of the aspiration experiment. The method assumes that breast tissue is composed of a bilayered structure made of fatty and fribroglandular tissues (lower layer) superimposed with the skin (upper layer). Young moduli of both layers are therefore estimated based on repeating low intensity suction tests (<40 mbar) of breast tissues using cups of 7 different diameters. FINDINGS: Seven volunteers were involved in this pilot study with average Young moduli of 56.3 kPa  ± 16.4 and 3.04 kPa  ± 1.17 respectively for the skin and the fatty and fibroglandular tissue. The measurements were carried out in a reasonable time scale (<60 min in total) without any discomfort perceived by the participants. These encouraging results should be confirmed in a clinical study that will include a much larger number of volunteers and patients.


Subject(s)
Elasticity Imaging Techniques , Breast/diagnostic imaging , Elastic Modulus , Elasticity Imaging Techniques/methods , Humans , Pilot Projects
17.
Nano Lett ; 22(16): 6476-6483, 2022 08 24.
Article in English | MEDLINE | ID: mdl-35929970

ABSTRACT

Water-enabled electricity generation (WEG) technologies are considered to be an attractive and renewable approach to meet energy crisis and environmental pollution globally. However, the existing WEG technologies still face tremendous challenges including high material cost, harmful components, and specific environmental requirements. Herein, a high-performance wood-based moisture-enabled electric generator (WMEG) is fabricated. Natural wood is cut perpendicular to the tree growth direction and engineered by simple chemical modification. The obtained bilayer wood membrane has robust mechanical framework with aligned ion nanochannels, abundant dissociated functional groups, and spontaneous water adsorption in the air. At the relative humidity of 85%, one WMEG can generate a voltage of 0.57 V. The device can also effectively sense biological water information as a self-powered sensor. The biophile design contributes a practical moist-electric generation strategy that offers clean energy, especially for undeveloped and disaster-relief regions where electricity is limited by high cost or crippled power facilities.


Subject(s)
Electricity , Wood , Adsorption , Water
18.
Nanomaterials (Basel) ; 12(7)2022 Mar 29.
Article in English | MEDLINE | ID: mdl-35407253

ABSTRACT

Conductive hydrogels are widely used in sports monitoring, healthcare, energy storage, and other fields, due to their excellent physical and chemical properties. However, synthesizing a hydrogel with synergistically good mechanical and electrical properties is still challenging. Current fabrication strategies are mainly focused on the polymerization of hydrogels with a single component, with less emphasis on combining and matching different conductive hydrogels. Inspired by the gradient modulus structures of the human skin, we propose a bilayer structure of conductive hydrogels, composed of a spray-coated poly(3,4-dihydrothieno-1,4-dioxin): poly(styrene sulfonate) (PEDOT:PSS) as the bonding interface, a relatively low modulus hydrogel on the top, and a relatively high modulus hydrogel on the bottom. The spray-coated PEDOT:PSS constructs an interlocking interface between the top and bottom hydrogels. Compared to the single layer counterparts, both the mechanical and electrical properties were significantly improved. The as-prepared hydrogel showed outstanding stretchability (1763.85 ± 161.66%), quite high toughness (9.27 ± 0.49 MJ/m3), good tensile strength (0.92 ± 0.08 MPa), and decent elastic modulus (69.16 ± 8.02 kPa). A stretchable strain sensor based on the proposed hydrogel shows good conductivity (1.76 S/m), high sensitivity (a maximum gauge factor of 18.14), and a wide response range (0−1869%). Benefitting from the modulus matching between the two layers of the hydrogels, the interfacial interlocking network, and the patch effect of the PEDOT:PSS, the strain sensor exhibits excellent interface robustness with stable performance (>12,500 cycles). These results indicate that the proposed bilayer conductive hydrogel is a promising material for stretchable electronics, soft robots, and next-generation wearables.

19.
Biochim Biophys Acta Biomembr ; 1864(7): 183907, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35247332

ABSTRACT

Amphiphysin and endophilin are two members of the N-BAR protein family. We have reported membrane interactions of the helix 0 of endophilin (H0-Endo). Here we investigate membrane modulations caused by the helix 0 of amphiphysin (H0-Amph). Electron paramagnetic resonance (EPR) spectroscopy was used to explore membrane properties. H0-Amph was found to reduce lipid mobility, make the membrane interior more polar, and decrease lipid chain orientational order. The EPR data also showed that for anionic membranes, H0-Endo acted as a more potent modulator. For instance, at peptide-to-lipid (P/L) ratio of 1/20, the peak-to-peak splitting was increased by 0.27 G and 1.89 G by H0-Amph and H0-Endo, respectively. Similarly, H0-Endo caused a larger change in the bilayer polarity than H0-Amph (30% versus 12% at P/L = 1/20). At P/L = 1/50, the chain orientational order was decreased by 26% and 66% by H0-Amph and H0-Endo, respectively. The different capabilities were explained by considering hydrophobicity score distributions. We employed atomic force microscopy to investigate membrane structural changes. Both peptides caused the formation of micron-sized holes. Interestingly, only H0-Amph induced membrane fusion as evidenced by the formation of high-rise regions. Lastly, experiments of giant unilamellar vesicles showed that H0-Amph and H0-Endo generated thin tubules and miniscule vesicles, respectively. Together, our studies showed that both helices are effective in altering membrane properties; the observed changes might be important for membrane curvature induction. Importantly, comparisons between the two peptides revealed that the degree of membrane remodeling is dependent on the sequence of the N-terminal helix of the N-BAR protein family.


Subject(s)
Nerve Tissue Proteins , Peptides , Cell Membrane/metabolism , Lipids/analysis , Nerve Tissue Proteins/metabolism , Peptides/metabolism
20.
J Colloid Interface Sci ; 616: 709-719, 2022 Jun 15.
Article in English | MEDLINE | ID: mdl-35247809

ABSTRACT

Bilayer solar evaporator combines high photothermal conversion capacity and low heat loss, has become the new darling in interfacial solar steam generation (ISSG). However, the bilayer structure generally achieved by introducing a photothermal coating on the substrate is not conducive to long-term use due to the poor stability of coating. Herein, a fully biomass-based bilayer evaporator is all-in-one designed, using chitosan (CS) as building blocks and CS derived N, S - doped porous carbon (NSPC) as fillers via pre-freezing and freeze-drying. This facile method could realise the quantitative addition of photothermal materials and controllably regulate the structure of the bilayer evaporator, making the structural optimisation readily available. The optimised evaporator exhibits a remarkable evaporation rate of 2.51 kg m-2h-1. After 1000 times of pressing, it still maintains at 2.42 kg m-2h-1. Additionally, the evaporator displays outstanding long-lasting stability, excellent salt-resistant and degradability. More importantly, a solar desalination device is fabricated for harvesting freshwater outdoor. The daily water production per unit area (4.55 kg) meets the consumption of two adults. This work provides a controllable synthesis strategy of bilayer evaporators for handling global freshwater shortages.


Subject(s)
Water Purification , Seawater , Sodium Chloride , Steam , Sunlight
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