ACS Applied Engineering Materials最新文献

During the foreign body response, immune cells are metabolically rewired after exposure to breakdown products of various biomaterials, including polylactide (PLA) and polyethylene. Particles of polyethylene interact with Toll-like receptor 4 on macrophages, resulting in increased oxygen consumption that forms reactive oxygen species at complex I of the mitochondrial electron transport chain (mETC). However, PLA degradation products bind to monocarboxylate transporters for downstream signaling with elevated oxygen consumption rates, whose functional implication is unclear and remains inferred from cellular responses to polyethylene biomaterials. By chemically probing the function of the mETC, we show that proinflammatory macrophages activated by exposure to amorphous PLA (aPLA) breakdown products rely on mitochondrial respiration for ATP production independent of oxygen consumption rates. In contrast, macrophages activated by semicrystalline PLA (cPLA) breakdown products exhibit a metabolic phenotype wherein ATP levels are unaffected by changing oxygen consumption rates. In subcutaneous implants, the incorporation of metformin in aPLA or cPLA to chemically inhibit complex I did not effectively modulate the proinflammatory response to biomaterials, suggesting that PLA degradation products elicit a distinct metabolic program, thus providing an alternative perspective on the role of mitochondrial respiration in the inflammatory response to biomaterials.

Here, we report the room-temperature dual discrimination of N,N-dimethylformamide (DMF) and aniline using a 1T′/2H mixed phase tungsten diselenide (WSe₂) chemiresistive gas sensor. Mixed phase WSe₂ microspheres were synthesized in a thermally controlled environment via a facile solvothermal method. Structural analysis using various characterization techniques confirmed the spherical flower-like morphology and presence of mixed phases. Further, a slight increase in the 1T′/2H ratio of WSe₂ showed a significant conductivity change, as confirmed using electrochemical impedance spectroscopy and two-terminal current voltage measurements. The sensing properties were investigated under varying relative humidity (40–90%) for two different devices made from WSe₂ synthesized at 200 and 220 °C, respectively. The sensing device created with WSe₂ synthesized at 200 °C exhibited response and recovery times of 157 and 68 s, respectively, for DMF (4 ppm). This device revealed a response of 2.77% toward 32 ppm DMF and a theoretically calculated limit of detection (LOD) of ∼114 ppb. The sensor created with WSe₂ synthesized at 220 °C displayed response and recovery times of 78 and 89 s, respectively, for aniline (3 ppm) under ambient conditions. This device exhibited a significant drop in response (0.04%) toward DMF in comparison to aniline and displayed a response of (1.07%) at room temperature with a calculated LOD of ∼250 ppb. The sensors showed higher resilience toward increased humidity levels. The absolutely clean, stable, and reproducible responses (2.35% and 1.61%) toward DMF and (0.9% and 0.66%) aniline vapors under relative humidities of 40% and 90%, respectively, confirm the durable behavior of the devices. The gas sensing mechanism was explained using appropriate energy level diagrams, as well as adequate surface reactions, which were then validated using the gas chromatography–mass spectroscopy (GC-MS) approach. The present work emphasizes a straightforward and facile approach to develop 1T′/2H mixed phase WSe₂ for the dual detection of DMF and aniline under ambient conditions.

Widespread use of batteries across the globe generates a huge amount of waste. This work is the first to report spent dry cell (Zn-Carbon) battery cathode material (BCM-2) as a heterogeneous catalyst for selective synthesis of fine chemical 2,5-diformylfuran (DFF). Cathode material was easily separated from spent batteries, and acid leached followed by calcination to obtain black powder that was denoted as BCM-2. The catalyst was characterized using various techniques such as P-XRD, EDAX, SEM, HR-TEM, TGA, XPS, and BET analysis. Superior catalytic activity was shown by the catalyst for selective formation of DFF using molecular O₂ as a sole oxidant. The catalyst was found to give excellent HMF conversion of 97% with 98% high selectivity of DFF. The BCM-2 catalyst was easily recycled and reused without any significant loss in its catalytic activity. This is one of the best examples for a sustainable, cost-effective, and highly efficient catalytic system for the synthesis of the value-added chemical DFF.

Two-photon-excited fluorescence imaging (TPEFI) is a rapidly advancing technique for detecting analytes and visualizing biological conditions in real time. Compared to conventional one-photon excitation, TPEFI offers advantages, such as deeper tissue penetration, reduced photodamage, high sensitivity, and superior temporal resolution, making it highly suitable for in vivo imaging applications. The integration of biostimuli-responsive elements into two-photon fluorophores has enabled the development of bioactivatable two-photon-excited small molecules that are effective in near-infrared bioimaging for monitoring diverse biological processes and diseases. This review highlights recent progress (2019–2024) in the design and application of two-photon-excited near-infrared fluorescent probes specifically developed for activity-based bioimaging. We provide a succinct overview of both chemically and enzymatically activated probes by discussing their structural design principles, bioresponsive characteristics, two-photon absorption and emission properties, and their use in vitro and in vivo for monitoring specific biomedical conditions and diseases.

The transdermal drug delivery system (TDDS) is a promising and innovative approach to drug delivery because of its noninvasiveness, potential for localized and prolonged drug delivery, and ability to minimize systemic side effects by avoiding first-pass metabolism. Utilizing the distinctive characteristics of hydrogels, such as their biocompatibility, versatility in administration, and higher drug loading capabilities, herein, we develop a biocompatible hydrogel through synergistically interacting the biopolymer k-carrageenan (k-CG) and metal–organic framework (MOF) (zeolitic imidazolate framework (ZIF-8)) that can work as a TDDS. The resultant hydrogel showcased remarkable properties necessary for being the TDDS, including superior mechanical strength, self-healing capabilities, adhesiveness, and spreadability. Notably, this hydrogel exhibits a substantial drug loading capacity, specifically 64.16 mg/g of the anticancer drug 5-fluorouracil (5-FU), with sustained release behavior of 71.8% within 72 h. The hydrogel demonstrated remarkable viability (∼95%) in MTT assays against HaCaT cells, indicating its excellent biocompatibility. The drug-loaded hydrogel effectively targeted TDDS, evidenced by in vitro cytotoxicity studies on MCF-7 breast cancer cells. Additionally, the hydrogel exhibited efficient curcumin (Cur) loading at 18 mg/g without affecting its stability, showcasing notable antibacterial and antioxidant properties. These findings suggest the potential of the investigated system for cancer therapy and wound healing applications.

Textile processing has had a negative impact on the environment in past decades, e.g., due to the usage of toxic chemicals and high amounts of contaminated wastewater. Therefore, the demand for bio-based and eco-friendly textile processing has strongly increased in the past few years. Polyethylene terephthalate (PET) is the most commonly used polymer in the clothing and technical textile sectors due to its excellent chemical and physical properties (e.g., low weight while being mechanically durable). However, its intrinsic hydrophobicity requires harsh pretreatment and processing before being fully usable as a product in the field of clothing and sportswear. To overcome these issues, we present a protein-based finish that improves the hydrophilicity of PET fabrics, thus improving the comfortability and suitability of PET fibers in sportswear. Fusion proteins consisting of a material binding anchor peptide (AP) and a functional moiety consisting of supercharged unfolded polypeptides (SUPs) were genetically engineered. The protein was produced in an easy, one-step, and scalable recombinant expression. Functionalization of PET with the AP-SUP fusion protein was achieved through dip coating in aqueous solution at room temperature, offering an energy efficient and resource saving textile finishing process that is compatible with existing machinery in the textile finishing industry. We successfully demonstrated that our ultrathin AP-SUP finish hydrophilized the textile surface, improved moisture management, and remained on the PET surface after washing.

Low-melting-point metals, known as liquid metals (LMs), have recently attracted significant interest owing to their high conductivity and fluidity. “Emulsification” of LMs into colloidal microdroplets in immiscible carrier fluids confers a variety of unique opportunities in terms of their processability as well as functionality; however, achieving emulsification at high LM loads while significantly modifying the rheology of the resulting emulsions presents a considerable challenge. Furthermore, the formation of a surface oxide skin on emulsified LM droplets complicates their interfacial dynamics and often deteriorates the performance of the resulting emulsions. In this study, we demonstrate that polyvinylpyrrolidone (PVP), which can coordinate-bond with LM, markedly increases the emulsification efficiency of LM in ethanol (EtOH), thereby enabling the formation of highly viscoelastic LM-in-EtOH emulsion pastes via simple shear mixing using a mortar and pestle. The growth of the oxide layer is controlled by the surface-adsorbed PVPs, which form an interdroplet percolation network. The resulting PVP-mediated “structured” emulsions exhibit significantly higher thermal conductivities than their additive-free counterparts under a given LM load, owing to the formation of an effective thermal transport network of interconnected conductive LM droplets with controlled growth of insulating oxide skin. Industry-relevant blade coating using these LM-in-EtOH emulsions is demonstrated, during which LM droplets coated on nonstretchable substrates readily develop anisotropy under applied shear, which may be potentially useful for directed thermal transport in relevant applications. Lastly, the performance of the LM droplets coated with PVP as thermal interface materials is evaluated.

Applying zero-energy-input passive radiative cooling technology to personal thermal management systems can promote sustainable development and decrease energy consumption. However, the nearly horizontal internal radiation between cooling textiles and their surroundings hinders the transmission of thermal radiation into outer space, thereby diminishing the effectiveness of radiative cooling, because most of the wearable fabric on the human body is oriented vertically. Herein, we develop a nanoprocessed wool fabric with wrinkled patterns using a molecular bonding design strategy and scalable dip-coating methods to enhance solar spectrum reflection, followed by a thermal setting to form louver-like wrinkles. The wrinkled structures form a reflective surface oriented toward the direction of sunlight, which not only effectively reflects solar radiation directionally into outer space but also creates shaded areas to reduce the solar fluxes reaching the wearable fabric by around 50%. Nanoprocessed wrinkled wool fabric reflects over 90% of solar irradiance and selectively transmits human thermal radiation, allowing simulated skin to remain up to 10 °C cooler under direct sunlight and 2 °C cooler indoors compared to cotton fabrics. Moreover, the wool fabric retains its inherent breathability and comfort and excellent wear resistance. This efficient and scalable fabric design paves the way for sustainable energy solutions, smart textiles, and passive radiative cooling applications through the use of natural materials and geometrical structure engineering.

Inspired by nature, photothermal-responsive shape memory and self-healing polymers demonstrate capabilities in self-sustainable and multifunctional actuation, which is highly promising for future smart wearables. However, their advancement in smart wearables is impeded by excessive surface heat generated from photothermal fillers, resulting in significant thermal discomfort for users. Herein, a high-performance photothermal-responsive shape memory and self-healing polymer is derived from a series of poly(urethane methacrylate)s (PUMAs) by meticulously modulating their microstructure and properties through the isocyanate-to-hydroxyl ratio and reactive diluent content. Its intrinsic photothermal properties, excellent shape recovery (ca. 98.7%), and high self-healing efficiency (ca. 93.4%) enable synergistic coupling effect of autonomous deformation recovery and crack healing. More importantly, its actuation temperature (ca. 35.2 °C) is much lower than the thermal discomfort threshold temperature range of the human body (ca. 43–48 °C), thereby enabling sunlight-induced shape memory and self-healing actuation at thermal comfort temperatures. In addition, end-functionalization of methacrylate moieties grants photocurability for integration in vat photopolymerization-based printing of smart wearables. The contribution of this work is centered on the low surface temperature achieved through photothermal effect (ca. 37.5 °C), which is adequate to trigger shape memory effect and self-healing while remaining within the thermal discomfort threshold temperature of the human body, offering an advantage over comparable materials. A four-dimensional (4D)-printed sneaker is created to demonstrate its shape memory and self-healing abilities under simulated and natural sunlight while simultaneously achieving thermal comfort. This work establishes a cornerstone for developing next-generation multifunctional smart wearables with end-user personalization and superior comfort of wear.

Removal of highly toxic and corrosive hydrogen sulfide from gas flows is of paramount importance for controlling the environment and in several industrial processes. This contribution reports a straightforward strategy to engineer sorbents for efficient hydrogen sulfide removal under humid conditions by functionalizing the open metal sites of metal–organic frameworks (MOFs) with polyamines. MIL-101(Cr) MOFs were successfully modified with ethylenediamine and tris(2-aminoethyl)amine, and the resulting materials were characterized using X-ray diffraction, FTIR, NMR, nitrogen sorption, and thermogravimetric analysis (TGA), confirming the functionalization. Although the functionalized MOFs exhibited a greater affinity for water compared to the unmodified MIL-101(Cr), they efficiently removed H₂S under humid conditions without framework degradation, whereas the pristine material did not. This was demonstrated by TGA-MS and elemental analysis and confirmed by density functional theory calculations. The developed approach offers a promising pathway for the design of advanced sorbents tailored for H₂S removal in industrial and environmental applications.