Search Results (40)

Alkaline electrolytic water hydrogen generation, a key driver in the growth of hydrogen energy, heavily relies on high-efficiency and high-purity ion exchange membranes. In this study, three-dimensional (3D) wrinkled reduced graphene oxide (WG) nanosheets obtained through a simple thermal reduction process and two-dimensional (2D) graphene oxide act as building blocks, with ethylenediamine as a crosslinking stabilizer, to construct a unique 3D/2D 2 nm-tunneling structure between the GO and WG sheets through via an amide connection at a WG/GO ratio of 1:1. Here, the wrinkled graphene (WG) undergoes a transition from two-dimensional (2D) graphene oxide (GO) into three-dimensional (3D) through the adjustment of surface energy. By increasing the interlayer spacing and the number of ion fluid channels within the membranes, the E-W/G membrane has achieved the rapid passage of hydroxide ions (OH⁻) and simultaneous isolation of produced gas molecules. Moreover, the dense 2 nm nano-tunneling structure in the electrolytic water process enables the E-W/G membrane to attain current densities >99.9% and an extremely low gas crossover rate of hydrogen and oxygen. This result suggests that the as-prepared membrane effectively restricts the unwanted crossover of gases between the anode and cathode compartments, leading to improved efficiency and reduced gas leakage during electrolysis. By enhancing the purity of the hydrogen production industry and facilitating the energy transition, our strategy holds great potential for realizing the widespread utilization of hydrogen energy. Full article

The microstructures of microalgae biofilms affect biofilms’ growth, which is critical in developing efficient microalgae biofilm-based culture systems. Herein, the microstructures of Tetradesmus obliquus biofilms cultured under different nutrients were in situ observed with confocal laser scanning microscopes. The surface structures and internal pore structures for these biofilms were determined quantitatively. The results indicated that the surfaces of these biofilms were all wrinkled with many folds in micrometres. The biofilms cultured under BG11, BG11^+glycerine, BG11^+urea, and BG11^+NH₄Cl nutrients had small pores with diameters of 15~30 μm, whereas the biofilms formed under BG11^+NaHCO₃ and BG11^+NaNO₃ presented many large pores with diameters of 50~150 μm. The mechanism of forming different microstructures of these nutrients was interpreted by analyzing cell surface properties. We found that the cells cultured under BG11^+NaHCO₃ and BG11^+NaNO₃ had more hydrophobic surface groups. The high cell–cell interactions between hydrophobic cells made cells tend to aggregate together and form biofilms with more inner pores, which may be conducive to cell growth and biofilm development. The study offers new insights into understanding the microstructural characteristics of microalgae biofilms cultured under different nutrients, providing important guidance for the development of biofilm-based culture systems. Full article

This study conducted a literature review by searching for articles related to the treatment of skin infections/wrinkles using nano-delivery systems containing natural compounds. The search was conducted in various databases for articles published in the last 10 years, with strict inclusion and exclusion criteria. Of the 490 articles found, 40 were considered relevant. Acne vulgaris is a common dermatological disorder characterised by inflammation of the sebaceous glands, often resulting in the development of pimples, cysts, and scarring. Conventional treatments, including antibiotics and topical retinoids, frequently demonstrate limitations such as side effects, resistance, and insufficient skin absorption. Recent advancements in nanotechnology have enabled the creation of innovative drug-delivery systems that enhance the effectiveness and reduce the adverse effects of anti-acne medications. Polyphenols and flavonoids, natural bioactive compounds with notable anti-inflammatory, antioxidant, and antibacterial properties, are recognised for their therapeutic effectiveness in acne treatment. However, their practical application is hindered by insufficient solubility, stability, and bioavailability. The incorporation of these compounds into nanoparticle-based delivery systems has shown promise in resolving these challenges. Various nanoparticle platforms, including lipid-based nanoparticles, polymeric nanoparticles, and solid lipid nanoparticles, are evaluated for their ability to improve the stability, controlled release, and targeted delivery of polyphenols and flavonoids to the skin. The advent of polyphenol and flavonoid-loaded nanoparticles marks a new acne therapy era. Full article

We present a versatile method for synthesizing high-quality molybdenum disulfide (MoS₂) crystals on graphite foil edges via chemical vapor deposition (CVD). This results in MoS₂/graphene heterostructures with precise epitaxial layers and no rotational misalignment, eliminating the need for transfer processes and reducing contamination. Utilizing in situ transmission electron microscopy (TEM) equipped with a nano-manipulator and tungsten probe, we mechanically induce the folding, wrinkling, and tearing of freestanding MoS₂ crystals, enabling the real-time observation of structural changes at high temporal and spatial resolutions. By applying a bias voltage through the probe, we measure the electrical properties under mechanical stress, revealing near-ohmic behavior due to compatible work functions. This approach facilitates the real-time study of mechanical and electrical properties of MoS₂ crystals and can be extended to other two-dimensional materials, thereby advancing applications in flexible and bendable electronics. Full article

Poly-d,l-lactic acid (PDLLA) is a biodegradable and biocompatible polymer that has garnered significant attention in dermatology due to its unique properties and versatile applications. This literature review offers a comprehensive analysis of PDLLA’s roles in various dermatological conditions and wound-healing applications. PDLLA demonstrates significant benefits in enhancing skin elasticity and firmness, reducing wrinkles, and promoting tissue regeneration and scar remodeling. Its biodegradable properties render it highly suitable for soft tissue augmentation, including facial and breast reconstruction. We discuss the critical importance of understanding PDLLA’s physical and chemical characteristics to optimize its performance and safety, with a focus on how nano- and micro-particulate systems can improve delivery and stability. While potential complications, such as granuloma formation and non-inflammatory nodules, are highlighted, effective monitoring and early intervention strategies are essential. PDLLA’s applications extend beyond dermatology into orthopedics and drug delivery, owing to its superior mechanical stability and biocompatibility. This review underscores the need for ongoing research to fully elucidate the mechanisms of PDLLA and to maximize its therapeutic potential across diverse medical fields. Full article

The efficient exploitation of planted fast-growing wood is crucial for enhancing wood resource utilization. In this study, the fast-growing poplar wood was modified by in situ impregnation through vacuum impregnation with polyvinyl alcohol and nano-silica sol as impregnation modifiers, combined with delignification–freezing pretreatment. The samples were characterized by FTIR, XRD, SEM, and the universal mechanical testing machine. The results showed that the wrinkle deformation and cracking of the wood blocks were greatly alleviated after the delignification–freezing pretreatment and the polyvinyl alcohol and nano-silica sol were successfully integrated into the wood. The resulting polyvinyl alcohol–silica sol poplar composites exhibited about 216%, 80% and 43% higher compressive strength with respect to delignified wood, natural wood and impregnated natural wood, respectively, thereby demonstrating superior mechanical properties and potential opportunities for value-added and efficient utilization of low-quality wood. Full article

Colloidal particle research has witnessed significant advancements in the past century, resulting in a plethora of studies, novel applications, and beneficial products. This review article presents a cost-effective and low-tech method for producing Janus elastomeric particles of varied geometries, including planar films, spherical particles, and cylindrical fibers, utilizing a single elastomeric material and easily accessible chemicals. Different surface textures are attained through strain application or solvent-induced swelling, featuring well-defined wavelengths ranging from sub-microns to millimeters and offering easy adjustability. Such versatility renders these particles potentially invaluable for medical applications, especially in bacterial adhesion studies. The coexistence of “young” regions (smooth, with a small surface area) and “old” regions (wrinkled, with a large surface area) within the same material opens up avenues for biomimetic materials endowed with additional functionalities; for example, a Janus micromanipulator where micro- or nano-sized objects are grasped and transported by an array of wrinkled particles, facilitating precise release at designated locations through wrinkle pattern adjustments. This article underscores the versatility and potential applications of Janus elastomeric particles while highlighting the intriguing prospects of biomimetic materials with controlled surface textures. Full article

This study aimed to determine the anti-collagenase, anti-elastase, and anti-hyaluronidase activities of Passiflora quadrangularis fruit extracts (epicarp, mesocarp, endocarp, and seed), develop stable nanoemulsions, and evaluate the efficacy of the nanoemulsions containing extracts in human volunteers. The results indicated that the epicarp and seed extracts exhibited collagenase, elastase, and hyaluronidase inhibition effects. Gallic acid was identified in the extracts, with the highest concentration found in the endocarp extract (1449.35 mg gallic acid/g extract) followed by the seed extract (839.63 mg gallic acid/g extract). The endocarp and seed extracts demonstrated good stability at different temperatures. Consequently, these extracts were selected for incorporation into nanoemulsions due to their high yield, excellent anti-tyrosinase and anti-aging activity, and good stability, making them suitable for cosmetic products. The nanoemulsions were prepared using the ultrasonication method, resulting in a particle size of 133.1 ± 0.8 nm, a polydispersity index of 0.33 ± 0.03, and a zeta potential of −61.8 ± 0.6 mV, indicating good stability. The nano-serum containing extracts was non-irritating and safe for the skin. Skin evaluation among human volunteers after 60 days of application revealed improvements in skin hydration and reduction in wrinkles. In conclusion, nanoemulsions containing P. quadrangularis fruit extracts have the potential to be effective cosmetic products. Full article

Pulmonary inflammations such as chronic obstructive pulmonary disease and cystic fibrosis are widespread and can be fatal, especially when they are characterized by abnormal mucus accumulation. Inhaled corticosteroids are commonly used for lung inflammations despite their considerable side effects. By utilizing particle engineering techniques, a combined dry powder inhaler (DPI) comprising nanosized ketoprofen-embedded mannitol-coated microparticles was developed. A nanoembedded microparticle system means a novel advance in pulmonary delivery by enhancing local pulmonary deposition while avoiding clearance mechanisms. Ketoprofen, a poorly water-soluble anti-inflammatory drug, was dispersed in the stabilizer solution and then homogenized by ultraturrax. Following this, a ketoprofen-containing nanosuspension was produced by wet-media milling. Furthermore, co-spray drying was conducted with L-leucine (dispersity enhancer) and mannitol (coating and mucuactive agent). Particle size, morphology, dissolution, permeation, viscosity, in vitro and in silico deposition, cytotoxicity, and anti-inflammatory effect were investigated. The particle size of the ketoprofen-containing nanosuspension was ~230 nm. SEM images of the spray-dried powder displayed wrinkled, coated, and nearly spherical particles with a final size of ~2 µm (nano-in-micro), which is optimal for pulmonary delivery. The mannitol-containing samples decreased the viscosity of 10% mucin solution. The results of the mass median aerodynamic diameter (2.4–4.5 µm), fine particle fraction (56–71%), permeation (five-fold enhancement), and dissolution (80% release in 5 min) confirmed that the system is ideal for local inhalation. All samples showed a significant anti-inflammatory effect and decreased IL-6 on the LPS-treated U937 cell line with low cytotoxicity. Hence, developing an innovative combined DPI comprising ketoprofen and mannitol by employing a nano-in-micro approach is a potential treatment for lung inflammations. Full article

In this work, we present an accessible benchtop fabrication technique to obtain a planar array of gold nanowrinkled surface electrodes (ANSE) for the construction of electrochemical cells, specifically to monitor soluble biomarkers of interest in cell culture environments. We present a complete characterization of the array and its response as an electrochemical cell. To validate our sensor, we evaluated the device sensitivity to detect nitric oxide (NO), an important molecule produced by endothelial cells as a response to environmental signals such as mechanics and growth factors. While testing measurements of nitric oxide in aqueous solutions with isotonic salt concentrations, we evidenced the influence of the environmental conditions for such electrochemical measurements, showing that the aqueous medium, usually not accounted for, significantly impacts the outcome. Finally, we present the application of the electrochemical sensor for the detection of nitric oxide released from stimulated endothelial cells as a proof of concept. Full article

The present study aimed to develop nanostructured lipid carriers (NLCs) and evaluate their effectiveness in enhancing the delivery and stability of vanillic and ferulic acid in the aqueous enzymatic extract of glutinous rice husk using a 0.5% w/w cellulase solution (CE0.5). NLCs were developed using a high-pressure homogenization technique and characterized for their particle size, polydispersity index, and zeta potential. The entrapment efficiency, physical and chemical stability, release profile, skin permeation, and skin retention of the NLCs loaded with CE0.5 were evaluated. It was observed that NLCs with high entrapment efficiencies efficiently encapsulate and protect both vanillic and ferulic acid, in contrast to a solution. The controlled and sustained release profile of vanillic acid and ferulic acid from NLCs suggests their potential for prolonged and targeted delivery. The findings also demonstrate the superior skin retention capabilities of NLCs without permeation compared to the solution. Notably, NLC2 exhibited the highest delivery into the skin layer, which can be attributed to its smaller particle size (107.3 ± 1.3 nm), enabling enhanced skin penetration. This research highlights the promising application of NLCs in enhancing the delivery and stability of bioactive compounds in cosmetic formulations and related fields. Full article

Synthesis of a smooth conductive film over an elastomer is vital to the development of flexible optics and wearable electronics, but applications are hindered by wrinkles and cracks in the film. To date, a large-scale wrinkle-free film in an elastomer has yet to be achieved. We present a robust method to fabricate wrinkle-free, stress-free, and optically smooth thin film in elastomer. Targeting underlying mechanisms, we applied nanoparticles between the film and elastomer to jam the interface and subsequently suppress interfacial instabilities to prevent the formation of wrinkles. Using polydimethylsiloxane (PDMS) and parylene-C as a model system, we have synthesized large-scale (>10 cm) wrinkle-free Al film over/in PDMS and demonstrated the principle of interface jamming by nanoparticles. We varied the jammer layer thickness to show that, as the layer exceeds a critical thickness (e.g., 150 nm), wrinkles are successfully suppressed. Nano-indentation experiments revealed that the interface becomes more elastic and less viscoelastic with respect to the jammer thickness, which further supports our assertion of the wrinkle suppression mechanism. Since the film was embedded in a polymer matrix, the resultant film was highly deformable, elastic, and optically smooth with applications for deformable optical sensors and actuators. Full article

We investigate the combined effects of surface diffraction and total internal reflection (TIR) in the design of 3-dimensional materials exhibiting distinct structural colour on various facets. We employ mechanical wrinkling to introduce surface diffraction gratings (from the nano to the micron scales) on one face of an elastomeric rectangular parallelepiped-shaped slab and explore the roles, in the perceived colours, of wrinkling pattern, wavelength, the directionality of incident light and observation angles. We propose a simple model that satisfactorily accounts for all experimental observations. Employing polydimethylsiloxane (PDMS), which readily swells in the presence of various liquids and gases, we demonstrate that such multifaceted colours can respond to their environment. By coupling a right angle triangular prism with a surface grating, we demonstrate the straightforward fabrication of a so-called GRISM (GRating + prISM). Finally, using a range of examples, we outline possibilities for a predictive material design using multi-axial wrinkling patterns and more complex polyhedra. Full article

In the present study KrF Excimer laser has been employed to irradiate the Cadmium (Cd) targets for various number of laser pulses of 500, 1000, 1500 and 2000, at constant fluence of 3.6 J cm⁻². Scanning Electron Microscopy (SEM) analysis was utilized to reveal the formation of laser induced nano/micro structures on the irradiated target (Cd) surfaces. SEM results show the generation of cavities, cracks, micro/nano wires/rods, wrinkles along with re-deposited particles during irradiation in air, whereas subsurface boiling, pores, cavities and Laser Induced Periodic Surface Structures (LIPSS) on the inner walls of cavities are revealed at the central ablated area after irradiation in propanol. The ablated volume and depth of ablated region on irradiated Cd targets are evaluated for various number of pulses and is higher in air as compared to propanol ambient. Fast Fourier Transform Infrared spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray Diffraction (XRD) analyses show the presence of oxides and hydro-oxides of Cd after irradiation in propanol, whereas the existence of oxides is observed after irradiation in air ambient. Nano-hardness tester was used to investigate mechanical modifications of ablated Cd. It reveals an increase in hardness after irradiation which is more pronounced in propanol as compared to air. Full article

Bone implants or replacements are very scarce due to the low donor availability and the high rate of body rejection. For this reason, tissue engineering strategies have been developed as alternative solutions to this problem. This research sought to create a cellular scaffold with an intricate and complex network of interconnected pores and microchannels using salt leaching and additive manufacturing (3D printing) methods that mimic the hierarchical internal structure of the bone. A biocompatible hydrogel film (based on poly-ethylene glycol) was used to cover the surface of different polymeric scaffolds. This thin film was then exposed to various stimuli to spontaneously form wrinkled micropatterns, with the aim of increasing the contact area and the material’s biocompatibility. The main innovation of this study was to include these wrinkled micropatterns on the surface of the scaffold by taking advantage of thin polymer film surface instabilities. On the other hand, salt and nano-hydroxyapatite (nHA) particles were included in the polymeric matrix to create a modified filament for 3D printing. The printed part was leached to eliminate porogen particles, leaving homogenously distributed pores on the structure. The pores have a mean size of 26.4 ± 9.9 μm, resulting in a global scaffold porosity of ~42% (including pores and microchannels). The presence of nHA particles, which display a homogeneous distribution according to the FE-SEM and EDX results, have a slight influence on the mechanical resistance of the material, but incredibly, despite being a bioactive compound for bone cells, did not show a significant increase in cell viability on the scaffold surface. However, the synergistic effect between the presence of the hydrogel and the pores on the material does produce an increase in cell viability compared to the control sample and the bare PCL material. Full article