查找使用阿拉丁产品的科研文献

Dual-functional PAAm/SA-Ca²⁺ hydrogel coating on polyurethane surfaces with lubrication and anti-encrustation functions

Lin Shiyun,Zhang Weihang,Hua Youlu,Mao Yanfa,Xv Qihang,You Deqiang,Cao Sheng,Wang Xiaojian

Polyurethane (PU) is widely used for ureteral stent, due to its low cost, good shape memory, and excellent biocompatibility. However, a major drawback of PU stents is their susceptibility to encrustation, where mineral deposits accumulate on the stent surface, potentially leading to blockage and infection. To address these challenges, this work proposes a polyacrylamide sodium alginate-calcium ion (PAAm/SA-Ca 2+ ) hydrogel coatings on PU and systematically evaluated the lubrication properties, mechanical stability, and anti-encrustation property of the coatings. PAAm/SA-Ca²⁺ hydrogel coatings of ~ 60 μm were successfully constructed on polyurethane surfaces using 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) as a bridging agent. Friction tests showed that friction coefficient of the coated surface was reduced from 0.85 (pristine PU) to 0.07, significantly enhancing the lubrication performance of PU. In vitro simulated urine mineralization immersion experiments confirmed that the modified surface reduced encrustation deposition by 92% within 7 days.

Environmental Self-Enhancement in PAM/SA Hydrogels: A Strategy for Deep Conformance Control in Heterogeneous Reservoirs

Shuai Zhou,Qiuyan Quan,Hongke Yang,Zhi Ye,Xueli Long,Tinglei Liu,Haien Yang,Dongzhi Yang

This study systematically investigates the swelling, time-dependent mechanical decay, and degradation of polyacrylamide (PAM)-based gels under simulated high-temperature reservoir conditions. A Ca2+-induced “environmentally self-enhancing” PAM/sodium alginate (SA) composite gel was designed to alleviate the pronounced performance decline caused by swelling and degradation. In this system, progressive cross-linking between SA and Ca2+ in formation water leads to the formation of an interpenetrating network (IPN), which contributes to improved structural stability. Experimental results indicate that incorporating 1.5% SA into a 20% PAM gel increases the swelling strength by a factor of 6.7, while the three-month strength retention improves from 14% to 50%. The composite gel also shows enhanced fatigue resistance and a delayed swelling response. In addition, PAM/SA microspheres prepared via inverse emulsion polymerization exhibit improved mechanical robustness after Ca2+ cross-linking, with the elastic modulus increasing by 36%. Core flooding experiments show that PAM/SA microspheres are able to gradually form stable plugging structures in porous media. After 7 days of swelling, the plugging ratio increases by 23% and the oil displacement efficiency improves by 3% compared with PAM microspheres. Microfluidic visualization further indicates that swollen microspheres form reconfigurable deposits within pore throats, which suppress preferential flow. Both the plugging pressure and the frequency of pressure fluctuations increase noticeably, and the displacement efficiency rises by 4%, reflecting enhanced flow field regulation. Overall, this study provides cross-scale experimental evidence for the environmentally induced strengthening mechanism of PAM/SA gels and suggests their potential application in deep conformance control.

Construction and Performance Evaluation of a Bifidobacterium Delivery System Based on TBP-SA Pickering Emulsion Gels

An emulsion gel (EG-B) was fabricated through in situ calcium crosslinking of Pickering emulsions stabilized by tartary buckwheat protein–sodium alginate (TBP-SA) nanocomplexes for the encapsulation and delivery ofBifidobacterium longum. Control samples, including free bacteria (Free-B), Pickering emulsions (PE-B), and oil-free hydrogels (HG-B), were used to assess encapsulation efficiency, microstructure, rheological properties, thermal stability, dilution stability, gastrointestinal resistance, storage stability, and colonic adhesion of EG-B. The EG-B exhibited a dual structure comprising a compact Pickering interfacial membrane and a continuous calcium alginate gel network with solid-like rheology (G′>>G″) and viscosity of approximately 100 Pa·s, achieving 92.66% encapsulation efficiency. Viable counts exceeded 6 log CFU/g after pasteurization (72 °C, 15 s) and reached 6.12 log CFU/g post-simulated gastrointestinal digestion, significantly surpassing those of PE-B (5.12 log CFU/g) and HG-B (4.45 log CFU/g). Furthermore, EG-B displayed the highest viable retention during 14-day storage at 4 °C and 25 °C, along with a greater colonic adhesion efficiency (55.64%) compared to PE-B (47.09%) and HG-B (44.65%). The combination of interfacial stabilization and gel network formation provided by the TBP-SA complex presents a straightforward, food-grade strategy for probiotic delivery.

A Coupled GSH/GSNOR System Denitrosylates TRXh5 to Allow Activation of SA Signalling by Oxidative Stress

Tao Chen,Shengchun Li,Xiujie Mu,Tianzhao Yang,Lijuan Wang,Mimi Tian,Mei Yu,Long Luo,Yuanming Xie,Wei Xuan,Graham Noctor,Yi Han

Accumulating evidence shows that reversible protein S -nitrosylation is essential for H 2 O 2 homoeostasis and signalling. However, roles for denitrosylation in such oxidative signalling remain poorly understood. Here, we examined this question using the Arabidopsis catalase-defective mutant, cat2 , in which oxidative stress induces both glutathione accumulation and salicylic acid (SA) pathways. Induction of these pathways was accompanied by enhanced thioredoxin ( TRXH5 ) expression, and oxidative stress-induced activation of the SA pathway was compromised when TRXH5 expression was genetically disabled, whereas TRXH5 overexpression stimulates H 2 O 2 -triggered SA responses. Intriguingly, TRX h5 -reinforced SA responses were antagonised by glutathione (GSH) deficiency when introducing additional pad2 mutation, localised in the GLUTAMATE-CYSTEINE LIGASE gene encoding the first enzyme of glutathione biosynthesis. Further analysis revealed that the two active cysteine residues of recombinant TRX h 5 can be denitrosylated by GSH. Blocking glutathione accumulation increased more TRX h 5-SNO formation in TRXH5-YFP cat2 pad2 trxh5 than in TRXH5-YFP cat2 trxh5 . Furthermore, S -nitrosoglutathione reductase (GSNOR) was capable of physically interacting with TRX h 5, and was also required for GSH-dependent TRX h 5 denitrosylation and TRX h 5-enhanced SA responses during oxidative stress. Collectively, these data suggest that GSH/GSNOR constitutes an active denitrosylating module that works together with the canonical NADPH-dependent TRX-reducing pathway to sustain cytosolic TRX h 5 operation within the oxidative signalling framework.

Preparation of ZnIn2S4/MoS2–SA Photocatalyst Gel for Wastewater Treatment: Photocatalytic Performance and Solar Interfacial Evaporation

Yuxuan Liu,Qianzhi Chen,Xiaoying Feng,JiYan Li,Hanxue Sun,Weidong Liang

With the rapid advancement of industrialization, wastewater pollution has become an increasingly severe environmental issue. The integration of photocatalysis with solar interfacial evaporation technology, which leverages the abundant and clean energy of solar power, has drawn growing attention as effective solutions to this problem. In this study, MoS2 nanosheets with low-dimensional and controllable morphology were successfully grown on layered ZnIn2S4 using a simple template method, resulting in a novel nanoflower heterojunction photocatalyst. This photocatalyst was then combined with sodium alginate, and aerogels were fabricated through directional freezing technology. The ZnIn2S4/MoS2 photocatalytic aerogel demonstrated excellent photocatalytic performance under visible light, efficiently degrading various pollutants such as rhodamine B(RhB)(30 min, 99%), methyl orange(MO)(30 min, 99%), tetracycline(TC)(1h, 88%), and other antibiotics and dyes. Notably, the degradation efficiency for tetracycline remained at 88% even after five cycles of use, highlighting the aerogel’s strong reusability and stability across different pollutants. Additionally, the current aerogel composite exhibits an evaporation rate of up to 1.984 kg m–2 h–1 and a photothermal conversion efficiency of 95.5%. These results demonstrate that the ZnIn2S4/MoS2 photocatalytic aerogel is a promising candidate for sustainable water treatment, with broad applicability and stable photocatalytic degradation efficiency and interfacial evaporation efficiency under different polluted environments.

Volatile organic compounds of Enterobacter asburiae SA-9 suppress Meloidogyne graminicola in Rice via multiple mechanisms

Shan Ye,Chenxi Xiang,Beibei Luo,Ruoyu Zhang,Yao Wang,Jinglei Chen,Zhuhong Yang,Zhong Ding

The rice root-knot nematode Meloidogyne graminicola causes severe yield losses in rice production, requiring eco-friendly control measures. Here, we isolated Enterobacter asburiae SA-9 from rice rhizosphere soil and evaluated the biocontrol potential of its volatile organic compounds (VOCs) against M. graminicola . In vitro, SA-9 VOCs exhibited potent fumigant activity, causing high mortality of second-stage juveniles (J2s) and significant inhibition of egg hatching. Chemotaxis assays showed that SA-9 disrupted nematode chemotaxis through repellent activity. Further investigations revealed that exposure to SA-9 VOCs significantly downregulated key chemosensory genes ( Mg-odr-1 , Mg-odr-3 , Mg-osm-9 , Mg-tax-4 ) in J2s, impairing their host-seeking and infection abilities. In double-layered pot, SA-9 VOCs effectively reduced root gall index and nematode populations, while concurrently promoting rice growth, accompanied by upregulation of auxin ( OsAUX1 , OsYUCCA1 ) and gibberellin ( OsGID1 ) biosynthesis-related genes. Furthermore, SA-9 VOCs induced genes related to systemic resistance in rice, as evidenced by the increased expression of defense-related genes in the salicylic acid ( OsPR1a , OsWRKY45 ) and jasmonic acid ( OsAOS2 , OsMYC2 ) signaling pathways. SPME-GC–MS profiling identified 12 VOCs produced by SA-9, with 2-phenylethanol, 2-methylbutyric acid, isobutyric acid and propanoic acid exhibiting significant contact and fumigation nematicidal activities against J2s. These findings demonstrate that SA-9 VOCs suppress M. graminicola through multiple mechanisms, highlighting their potential as sustainable biocontrol agents for managing root-knot nematodes in rice agroecosystems.

Immobilization on magnetic PVA/SA@Fe3O4 hydrogel beads enhances the activity and stability of neutral protease

Yun-Tao Zhao,Kun Zhang,Jian Zeng,Haowen Yin,Wenjing Zheng,Rui Li,Anzi Ding,Shaohong Chen,You Liu,Wenjin Wu,Zhanxin Jing

Enzyme immobilization technology has a key role in improving the stability of enzyme reaction systems and biocatalyst utilization rates. In this study, polyvinyl alcohol/sodium alginate@Fe 3 O 4 (PVA/SA@Fe 3 O 4 ) magnetic immobilized-enzyme hydrogel beads were prepared. Their structure and morphology were characterized by scanning electron microscopy, surface area and porosity analyses, Fourier transform infrared spectroscopy , X-ray photoelectron spectroscopy and a vibrating sample magnetometer. The capability of PVA/SA@Fe 3 O 4 to adsorb neutral protease was investigated with variations in composition, temperature, pH, stirring speed, enzyme concentration, and crosslinking concentration. The optimal parameters of the immobilization process were determined by response surface methodology (3% neutral protease, 4% crosslinking at 200 rpm, 45 °C and pH 7.2), under which an immobilization rate of 41.98 mg/g was obtained. The thermal stability , acid-base stability, and reusability of the immobilized enzyme were improved significantly. After seven cycles, the immobilized enzyme activity remained at 30.8% that of the initial enzyme activity . The results indicate that the immobilization of NP onto magnetic PVA/SA@Fe 3 O 4 hydrogel beads improves enzyme efficiency, giving this process potential industrial applications.

A Green, Facile, and Scalable Method for Fabricating High-Strength, Water-Resistant CNF/SA Composite Films

Lijiaqi Zhang,Chao Wang,Yong Huang,Min Wu

Cellulose nanofiber (CNF) film has been widely studied in recent years because of its high strength, high light transmittance, degradability, and low thermal expansion coefficient. However, challenges like shrinkage, long dehydration times, and poor water resistance limit its large-scale application. Herein, we report a facile and environmentally friendly method to prepare CNF/sodium alginate (SA) composite films. By adding a certain amount of SA in the CNF film and regulating the moisture in the film, the gap between CNF was filled and the dimensional stability of the film was improved. Meanwhile, the cross-linking property of SA significantly reduced the water absorption rate of the composite film, endowing the composite film with high strength (dry strength 125 MPa), high water resistance (wet strength 33 MPa), and high light transmittance (85–90%). Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) analyses confirmed the microstructure and interaction mechanism of CNF and SA in composite films. This method is not only simple to operate without using toxic or harmful reagents but also effective to inhibit the deformation during the drying process of CNF, which is expected to provide a feasible basis for the commercial application of CNF film.

Preparation of FK-SA conjugate gel beads with double cross-linking for pH-controllable drug releasing

Wang Zejun,Ren Jiarui,Qian Lizhong,He Yufeng,Song Pengfei,Wang Rongmin

Using feather keratin (FK), a kind of biocompatible natural polymer being extracted from widely available and renewable waste feathers, and sodium alginate (SA) as materials, the FK conjugated SA gel beads (FK-SA-Gbs) were prepared with double cross-linked by calcium ion (Ca 2+ ) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). After being characterized and analyzed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD), its pH responsiveness, salt ion responsiveness, and degradability were measured, and the loading capacity of model drug Rhodamine B (RhB) under various physical conditions, the cumulative release rate of the loaded gel beads in different pH buffer solutions were also investigated. The results showed that the FK-SA-Gbs had significant pH sensitivity and sustained release, and various physical conditions can meet the requirements of wound dressings. It indicated FK-SA-Gbs can be used as controlled release drug carriers and are expected to be used as drug carrier materials in biomedical applications. Graphical abstract FK conjugated SA gel beads (FK-SA-Gbs) was prepared by secondary cross-linking with CaCl 2 and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC/HCl) using feather keratin (FK) extracted from waste feathers, which have significant pH sensitivity and sustained release capability.

Preparation of SA/P(U-AM-ChCl) composite hydrogels by frontal polymerization and its performance study

Bin Li,Aolin Wu,Wenrui Hao,Jizhen Liu,Zhigang Hu,Ying Wang

Deep eutectic solvent (DES) was synthesized from urea (U), acrylamide (AM) and choline chloride (ChCl), sodium alginate (SA) was selected as filler, and SA/P(U-AM-ChCl) composite hydrogel was prepared by thermal initiation frontal polymerization (FP). The hydrogels were characterised by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The effects of SA on the swelling properties, mechanical properties and self-healing properties of the composite hydrogels were investigated. The results show that the swelling properties of the composite hydrogel with the addition of SA are greatly enhanced due to the large number of hydroxyl groups contained in the SA chain. The tensile strength of the hydrogel gradually increased with increasing SA content, with the maximum tensile strength increasing by a factor of 2.89. The self-healing efficiency of the composite hydrogel gradually increased with the increase of SA, and the healing rate of FP5 reached 94.4% after 48 h of healing. This study provides a simple and rapid method for the preparation of composite hydrogels with good mechanical properties and self-healing properties.

Mussel-inspired HA@TA-CS/SA biomimetic 3D printed scaffolds with antibacterial activity for bone repair

Ji Cheng,Zhang Chengcheng,Xu Zeya,Chen Yan,Gan Yanming,Zhou Minghui,Li Lan,Duan Qinying,Huang Tingting,Lin Jinxin

Bacterial infection is a major challenge that could threaten the patient’s life in repairing bone defects with implant materials. Developing functional scaffolds with an intelligent antibacterial function that can be used for bone repair is very important. We constructed a drug delivery (HA@TA-CS/SA) scaffold with curcumin-loaded dendritic mesoporous organic silica nanoparticles (DMON@Cur) via 3D printing for antibacterial bone repair. Inspired by the adhesion mechanism of mussels, the HA@TA-CS/SA scaffold of hydroxyapatite (HA) and chitosan (CS) is bridged by tannic acid (TA), which in turn binds sodium alginate (SA) using electrostatic interactions. The results showed that the HA@TA-CS/SA composite scaffold had better mechanical properties compared with recent literature data, reaching 68.09 MPa. It displayed excellent degradation and mineralization capabilities with strong biocompatibility in vitro. Furthermore, the antibacterial test results indicated that the curcumin-loaded scaffold inhibited S.aureus and E.coli with 99.99% and 96.56% effectiveness, respectively. These findings show that 3D printed curcumin-loaded HA@TA-CS/SA scaffold has considerable promise for bone tissue engineering.

Enhancing the Toughness of PAA/LCNF/SA Hydrogel through Double-Network Crosslinking for Strain Sensor Application

Xin Li,Hui Gao,Qiang Wang,Shanshan Liu

Lignin-containing nanocellulose fibers (LCNF) have been considered as a valuable enhancer for polyacrylic acid (PAA)-based hydrogels that can form rigid porous network structures and provide abundant polar groups. However, the PAA–LCNF hydrogel is dominated by a single-network (SN) structure, which shows certain limitations when encountering external environments with high loads and large deformations. In this paper, sodium alginate (SA) was introduced into the PAA–LCNF hydrogel network to prepare a double-network (DN) hydrogel structure of the SA-Ca2+and PAA–LCNF through a two-step process. The covalent network of PAA–LCNF acts as the resilient framework of the hydrogel, while the calcium bridging networks of SA, along with the robust hydrogen bonding network within the system, function as sacrificial bonds that dissipate energy and facilitate stress transfer. The resulting hydrogel has porous morphologies. Results show that SA can effectively improve the mechanical properties of DN hydrogels and endow them with excellent thermal stability and electrical conductivity. Compared with pure PAA–LCNF hydrogel, the elongation at break of DN hydrogel increased from 3466% to 5607%. The good electrical conductivity makes it possible to use the flexible sensors based on DN hydrogel to measure electrophysiological signals. Our results can provide a reference for developing multifunctional hydrogels that can withstand ultra large deformation.