Chitosan

壳聚糖
  • 文章类型: Journal Article
    The construction of N, P co-doped hierarchically porous carbons (NPHPC) by a facile and green approach is crucial for high-performance energy storage but still an enormous challenge. Herein, an environment-friendly \"in-situ co-doping, self-regulation-activation\" strategy is presented to one-pot synthesize NPHPC using a phytic acid-induced polyethyleneimine/chitosan gel (PEI-PA-CS) as single precursor. NPHPC displayed a specific surface area of up to 1494 m2 g-1, high specific capacitance of 449 F g-1 at 1 A g-1, outstanding rate capability and cycling durability in a wide temperature range (-20 to 60 °C). NPHPC and PEI-PA-CS electrolyte assembled symmetric quasi-solid-state flexible supercapacitor presents superb energy outputs of 27.06 Wh kg-1 at power density of 225 W kg-1. For capacitive deionization (CDI), NPHPC also exhibit an excellent salt adsorption capacity of 16.54 mg g-1 in 500 mg L-1 NaCl solution at a voltage of 1.4 V, and regeneration performance. This study provides a valuable reference for the rational design and synthesis of novel biomass-derived energy-storage materials by integrating phytic acid induced heteroatom doping and pore engineering.
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  • 文章类型: Journal Article
    Developing plastic/fluorine/silicon-free and degradable water/oil-resistant coatings for paper-based packaging materials to replace disposable plastic products is a very effective way to solve the problem of \'white pollution\' or microplastics pollution. A novel water/oil-resistant coating was developed by alkyl ketene dimer (AKD)-based Pickering emulsion and chitosan in this work. Cellulose nanofibrils (CNF) were used as a stabilizing solid for AKD emulsion, with the addition of chitosan as an oil-resistance agent. The coating provides excellent hydrophobicity, water/oil resistance as well as good barrier properties. The water contact angle was as high as 130° and the minimum Cobb60 value was 5.7 g/m2, which was attributed to the hydrophobicity of AKD. In addition, the kit rating reached maximum 12/12 at coating weight of 8.26 g/m2 and the water vapor transmittance rate (WVTR) was reduced to 153.4 g/(m2⋅day) at the coating weight of 10.50 g/m2. The tensile strength of the paper was increased from 28.1 to 43.6 MPa after coating. Overall, this coating can effectively improve the performance of paper-based materials, which may play an important role in the process of replacing disposable plastic packaging with paper-based materials.
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  • 文章类型: Journal Article
    土壤有机质在镉的吸附和固定化中起着重要作用。由于不同的有机物成分对镉吸附过程的影响不同,选择正确的有机底物并知道如何应用它可以改善镉的修复。这项研究比较了两种不同的有机分子的影响;壳聚糖和柠檬酸,酸性Ultisol中镉的吸附和形态形成。壳聚糖对Ultisol的吸附显着增加了土壤的正电荷,而柠檬酸的吸附增加了土壤的负电荷。在pH5.0时,过量壳聚糖中镉的最大吸附量比过量柠檬酸中的最大吸附量大341%。在pH4.0时,约有73-89%和60-62%的吸附镉与Fe/Mn氧化物和有机物/硫化物结合,而在pH5.0时,柠檬酸和壳聚糖的这一比例分别为77-100%和57-58%。壳聚糖络合能力的降低与高pH对壳聚糖结构的不稳定作用有关。此外,壳聚糖的顺序,柠檬酸,和镉被添加到吸附系统中影响吸附曲线,这在pH梯度上是不同的。具体来说,与在pH3.0-6.5内预吸附壳聚糖相比,添加壳聚糖和镉一起增加了吸附。然而,对于柠檬酸,与pH6.5和7.5相比,添加顺序对pH3.0-4.0之间的镉吸附没有显着影响,过量的柠檬酸通常会抑制吸附。鉴于柠檬酸在土壤中的作用是短暂的,壳聚糖是一种很好的固定镉的土壤改良材料。
    Soil organic matter plays an important role in cadmium adsorption and immobilization. Since different organic matter components affect cadmium adsorption processes differently, selecting the right organic substrate and knowing how to apply it could improve cadmium remediation. This study compares the effects of two contrasting organic molecules; chitosan and citric acid, on cadmium adsorption and speciation in acidic Ultisol. The adsorption of chitosan to Ultisol significantly increased the soil positive charge while adsorption of citric acid increased the soil negative charge. At pH 5.0, the maximum amount of cadmium adsorbed in excess chitosan was 341% greater than that in excess citric acid. About 73-89% and 60-62% of adsorbed cadmium were bound to Fe/Mn oxides and organic matter/sulfide at pH 4.0 while this fraction was 77-100% and 57-58% for citric acid and chitosan at pH 5.0, respectively. This decrease in the complexing ability of chitosan was related to the destabilizing effect of high pH on chitosan\'s structure. Also, the sequence through which chitosan, citric acid, and cadmium were added into the adsorption system influenced the adsorption profile and this was different along a pH gradient. Specifically, adding chitosan and cadmium together increased adsorption compared to when chitosan was pre-adsorbed within pH 3.0-6.5. However, for citric acid, the addition sequence had no significant effect on cadmium adsorption between pH 3.0-4.0 compared to pH 6.5 and 7.5, with excess citric acid generally inhibiting adsorption. Given that the action of citric acid is short-lived in soil, chitosan could be a good soil amendment material for immobilizing cadmium.
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  • 文章类型: Journal Article
    背景:糖尿病伤口面临重大挑战,特别是在细菌感染和延迟愈合方面。因此,解决局部细菌问题和促进伤口加速愈合至关重要。在这次调查中,我们利用静电纺丝来制造包封MXene包封的微凝胶和壳聚糖/明胶聚合物的微凝胶/纳米纤维膜。
    结果:薄膜敷料促进了近红外(NIR)下的程序化光热疗法(PPT)和轻度光热疗法(MPTT),展示快速和广泛的抗菌和生物膜破坏能力。PPT效果在52°C下在5分钟内实现快速灭菌,并在10分钟内分散成熟的生物膜。同时,通过调整NIR功率以引起局部温和加热(42°C),敷料刺激成纤维细胞增殖和迁移,显着增强血管化。此外,体内实验成功验证了薄膜敷料,强调其在解决糖尿病伤口的复杂性方面的巨大潜力。
    结论:负载MXene微凝胶的纳米纤维敷料采用温度协调的光热疗法,有效地融合了高温灭菌和低温促进伤口愈合的优点。它表现得很快,广谱抗菌和生物膜破坏能力,特殊的生物相容性,对促进细胞增殖和血管化具有显著的作用。这些结果肯定了我们的纳米纤维敷料的功效,强调其在解决糖尿病伤口因感染而难以愈合的挑战方面的巨大潜力。
    BACKGROUND: Diabetic wounds present significant challenges, specifically in terms of bacterial infection and delayed healing. Therefore, it is crucial to address local bacterial issues and promote accelerated wound healing. In this investigation, we utilized electrospinning to fabricate microgel/nanofiber membranes encapsulating MXene-encapsulated microgels and chitosan/gelatin polymers.
    RESULTS: The film dressing facilitates programmed photothermal therapy (PPT) and mild photothermal therapy (MPTT) under near-infrared (NIR), showcasing swift and extensive antibacterial and biofilm-disrupting capabilities. The PPT effect achieves prompt sterilization within 5 min at 52 °C and disperses mature biofilm within 10 min. Concurrently, by adjusting the NIR power to induce local mild heating (42 °C), the dressing stimulates fibroblast proliferation and migration, significantly enhancing vascularization. Moreover, in vivo experimentation successfully validates the film dressing, underscoring its immense potential in addressing the intricacies of diabetic wounds.
    CONCLUSIONS: The MXene microgel-loaded nanofiber dressing employs temperature-coordinated photothermal therapy, effectively amalgamating the advantageous features of high-temperature sterilization and low-temperature promotion of wound healing. It exhibits rapid, broad-spectrum antibacterial and biofilm-disrupting capabilities, exceptional biocompatibility, and noteworthy effects on promoting cell proliferation and vascularization. These results affirm the efficacy of our nanofiber dressing, highlighting its significant potential in addressing the challenge of diabetic wounds struggling to heal due to infection.
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  • 文章类型: Journal Article
    随着人们对食品安全和公众健康的日益重视,正在努力开发可靠的,非侵入性方法来评估不同食品的新鲜度。基于壳聚糖的食品新鲜度指标,利用生物相容性等特性,生物降解性,无毒性,和高稳定性,在储存和运输过程中提供实时监控食品质量的创新方法。这篇综述介绍了智能食品新鲜度指标,特别是那些使用酸碱度敏感的染料,如花青素,姜黄素,Alizarin,紫草,还有Betacyanin.它突出了基于壳聚糖的智能食品新鲜度指标的好处,强调屏障和机械性能的改进,抗菌活性,和复合膜的溶解性。然后探讨这些指标在食品工业中的应用,同时简要概述了壳聚糖的局限性。本文最后讨论了利用壳聚糖开发智能食品新鲜度指标的挑战和未来研究的潜在领域。因此,基于壳聚糖的智能食品保鲜指标代表了一种提供实时数据以监测食品质量的创新方法,为客户和零售商提供有价值的见解,在推动食品工业发展中发挥着举足轻重的作用。
    With an increasing emphasis on food safety and public health, there is an ongoing effort to develop reliable, non-invasive methods to assess the freshness of diverse food products. Chitosan-based food freshness indicators, leveraging properties such as biocompatibility, biodegradability, non-toxicity, and high stability, offer an innovative approach for real-time monitoring of food quality during storage and transportation. This review introduces intelligent food freshness indicators, specifically those utilizing pH-sensitive dyes like anthocyanins, curcumin, alizarin, shikonin, and betacyanin. It highlights the benefits of chitosan-based intelligent food freshness indicators, emphasizing improvements in barrier and mechanical properties, antibacterial activity, and composite film solubility. The application of these indicators in the food industry is then explored, alongside a concise overview of chitosan\'s limitations. The paper concludes by discussing the challenges and potential areas for future research in the development of intelligent food freshness indicators using chitosan. Thus, chitosan-based smart food preservation indicators represent an innovative approach to providing real-time data for monitoring food quality, offering valuable insights to both customers and retailers, and playing a pivotal role in advancing the food industry.
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  • 文章类型: Journal Article
    众所周知,破骨细胞活性受到细胞内pH波动的显著影响。因此,pH敏感的门控纳米药物递送系统代表了减轻破骨细胞过度活性的有希望的治疗方法。我们之前的研究表明,柚皮苷,一种天然类黄酮,有效减轻破骨细胞活性。然而,柚皮苷的口服利用率低,半衰期短,阻碍了其临床应用。我们开发了一种药物递送系统,其中壳聚糖,作为看门人,包覆载有柚皮苷(CS@MSNs-柚皮苷)的介孔二氧化硅纳米颗粒。然而,CS@MSNs-柚皮苷对破骨细胞的抑制作用和潜在机制尚不清楚,保证进一步的研究。
    首先,我们合成了CS@MSNs-柚皮苷,并进行了全面表征。我们还测量了pH梯度溶液中的药物释放速率并验证了其生物安全性。随后,我们研究了CS@MSNs-柚皮苷对骨髓源性巨噬细胞诱导的破骨细胞的影响,在探索潜在机制的同时,重点关注分化和骨吸收活性。最后,我们建立了大鼠双侧临界大小的颅骨缺损模型,其中CS@MSNs-柚皮苷分散在GelMA水凝胶中以实现原位药物递送。我们观察到CS@MSNs-柚皮苷在体内促进骨再生和抑制破骨细胞活性的能力。
    CS@MSNs-柚皮苷表现出高的均匀性和分散性,低细胞毒性(浓度≤120μg/mL),和显著的pH敏感性。体外,与Naringin和MSNs-Naringin相比,CS@MSNs-柚皮苷更有效地抑制破骨细胞的形成和骨吸收活性。这种作用伴随着NF-κB和MAPK信号通路中关键因子的磷酸化减少,细胞凋亡水平增加,以及随后的破骨细胞特异性基因和蛋白质的产生减少。在体内,CS@MSNs-Naringin的表现优于Naringin和MSNs-Naringin,促进新骨形成,同时更大程度地抑制破骨细胞活性。
    我们的研究表明,CS@MSNs-Naringin在体外和体内表现出惊人的抗破骨细胞能力,而且促进颅骨缺损的骨再生。
    UNASSIGNED: It is well-established that osteoclast activity is significantly influenced by fluctuations in intracellular pH. Consequently, a pH-sensitive gated nano-drug delivery system represents a promising therapeutic approach to mitigate osteoclast overactivity. Our prior research indicated that naringin, a natural flavonoid, effectively mitigates osteoclast activity. However, naringin showed low oral availability and short half-life, which hinders its clinical application. We developed a drug delivery system wherein chitosan, as gatekeepers, coats mesoporous silica nanoparticles loaded with naringin (CS@MSNs-Naringin). However, the inhibitory effects of CS@MSNs-Naringin on osteoclasts and the underlying mechanisms remain unclear, warranting further research.
    UNASSIGNED: First, we synthesized CS@MSNs-Naringin and conducted a comprehensive characterization. We also measured drug release rates in a pH gradient solution and verified its biosafety. Subsequently, we investigated the impact of CS@MSNs-Naringin on osteoclasts induced by bone marrow-derived macrophages, focusing on differentiation and bone resorption activity while exploring potential mechanisms. Finally, we established a rat model of bilateral critical-sized calvarial bone defects, in which CS@MSNs-Naringin was dispersed in GelMA hydrogel to achieve in situ drug delivery. We observed the ability of CS@MSNs-Naringin to promote bone regeneration and inhibit osteoclast activity in vivo.
    UNASSIGNED: CS@MSNs-Naringin exhibited high uniformity and dispersity, low cytotoxicity (concentration≤120 μg/mL), and significant pH sensitivity. In vitro, compared to Naringin and MSNs-Naringin, CS@MSNs-Naringin more effectively inhibited the formation and bone resorption activity of osteoclasts. This effect was accompanied by decreased phosphorylation of key factors in the NF-κB and MAPK signaling pathways, increased apoptosis levels, and a subsequent reduction in the production of osteoclast-specific genes and proteins. In vivo, CS@MSNs-Naringin outperformed Naringin and MSNs-Naringin, promoting new bone formation while inhibiting osteoclast activity to a greater extent.
    UNASSIGNED: Our research suggested that CS@MSNs-Naringin exhibited the strikingly ability to anti-osteoclasts in vitro and in vivo, moreover promoted bone regeneration in the calvarial bone defect.
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  • 文章类型: Journal Article
    在这项工作中,合成了一种Z型异质结构的BiOCOOH/O-gC3N4材料,并将其固定在壳聚糖(CTS)上,获得了用于光催化降解盐酸土霉素(CTC)的BiOCOOH/O-gC3N4/CTS光催化材料。我们的研究结果表明,复合材料BiOCOOH/O-gC3N4,以及BiOCOOH/O-gC3N4/CTS复合膜,与单独使用BiOCOOH相比,CTC的光催化降解效率明显更高,由于吸附和光催化的协同作用。在四个使用周期之后,复合材料保留了其初始光催化降解活性的96%左右。在光催化材料中添加CTS解决了粉末材料通常遇到的聚集和难以回收等问题,从而促进光催化活性位点与CTC之间的有效碰撞。实验和理论计算证实了BiOCOOH和O-gC3N4的组合有效地提高了光吸收能力和光催化性能。此外,考察了pH值、阴离子等环境因素对光催化降解实验的影响,这为复合催化剂在废水处理中的应用提供了有价值的见解。
    In this work, a Z-scheme heterostructured BiOCOOH/O-gC3N4 material was synthesized and immobilized on chitosan (CTS) to obtain the BiOCOOH/O-gC3N4/CTS photocatalytic material for photocatalytic degradation of oxytetracycline hydrochloride (CTC).Our findings indicate that the composite material BiOCOOH/O-gC3N4, as well as the BiOCOOH/O-gC3N4/CTS composite membrane, displayed a significantly higher efficiency in photocatalytic degradation of CTC compared to BiOCOOH alone, owing to the synergistic effect of adsorption and photocatalysis. Following four cycles of use, the composite material retained around 96 % of its initial photocatalytic degradation activity. The addition of CTS in the photocatalytic material resolved issues such as aggregation and difficult recovery commonly encountered with powder materials, thereby facilitating effective collision between the photocatalytic active sites and CTC. Experimental and theoretical calculations provided confirmation that the combination of BiOCOOH and O-gC3N4 effectively enhanced the light absorption capacity and photocatalytic performance. Furthermore, we investigated the influence of environmental factors such as pH value and anions on the photocatalytic degradation experiment, which offers valuable insights for the application of composite catalysts in wastewater treatment.
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  • 文章类型: Journal Article
    在这项工作中,采用分步浸涂(SBS)方法,通过减少多层聚电解质的构造,有效改善了LBL的缺点。生物基阻燃剂,植酸(PA),和壳聚糖(CS)在经表氯醇改性芳纶纳米纤维(AEP)处理的棉织物表面进一步自组装,离子液体(IL),和铜离子。纯棉织物在每次浸渍液中只浸渍一次,提高防火安全性和抗菌性能。经处理的棉花在垂直可燃性测试中具有59毫米的炭长,极限氧指数(LOI)值从18.5%提高到38.5%。锥形量热仪测试(CCT)的结果表明,阻燃棉的火灾危险性明显下降(例如,峰值放热率(pHRR)和总放热率(THR)下降~44.1%和55.4%)。引人注目的是,处理后的棉花对大肠杆菌和金黄色葡萄球菌的活性有明显的抑制作用。经过阻燃整理的棉织物具有优异的防火安全性和抗菌性能。
    In this work, the step-by-step dip-coating (SBS) method was used to effectively improve the drawback of LBL by reducing the construction of a multilayer polyelectrolyte. Bio-based flame retardants, phytic acid (PA), and chitosan (CS) were further self-assembly on the surface of cotton fabric treated by epichlorohydrin-modified aramid nanofibers (AEP), ionic liquid (IL), and Cu ion. The pure cotton fabric was immersed in each dipping liquid only once, improving fire safety and antibacterial performance. The treated cotton self-extinguished with a 59 mm char length in the vertical flammability test, and the limiting oxygen index (LOI) value increased from 18.5 % to 38.5 %. The result of the cone calorimeter test (CCT) revealed that the fire hazard of flame-retardant cotton noteworthy declined (e.g., ~44.1 % and 55.4 % decline in peak heat release rate (pHRR) and total heat release rate (THR)). Conspicuously, the treated cotton exhibited a remarkably inhibiting effect on E. coli and S. aureus activity. The cotton fabric after flame-retardant finishing exhibited excellent fire safety and antibacterial performance.
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  • 文章类型: Journal Article
    通过将壳聚糖吸附的月桂酸酯酯化淀粉姜黄素Pickering乳液掺入淀粉膜基质中,制备了多功能活性智能生物质膜。纳米纤维素作为增强剂。薄膜的力学和功能性能进行了研究,这部电影被用来监测猪肉的新鲜度。结果证明姜黄素和Pickering乳液液滴在膜基质中相对均匀地分布。此外,加入姜黄素Pickering乳液对热稳定性的影响最小,同时薄膜的拉伸强度和拉伸应变增加,其疏水性和抗氧化性能均得到改善。自由基清除率达到56.01%,即使在8天后也具有持续的高抗氧化能力。此外,姜黄素的存在为薄膜提供了pH指示能力和延迟的猪肉腐败。因此,这项工作为建设绿色提供了一个有吸引力的策略,活跃,和用于肉类包装应用的智能生物质包装膜。
    The multifunctional active smart biomass film was prepared by incorporating chitosan-adsorbed laurate esterified starch curcumin Pickering emulsion into the starch film matrix, with nano-cellulose serving as reinforcing agents. The mechanical and functional properties of the film were studied, and the film was used to monitor the freshness of pork. The results demonstrated a relatively uniform distribution of curcumin and Pickering emulsion droplets within the film matrix. Furthermore, the thermal stability was minimally impacted by the introduction of curcumin Pickering emulsion, while the tensile strength and tensile strain of the film were increased, and both its hydrophobicity and antioxidant properties were improved. The free radical scavenging rate reached 56.01 %, with sustained high antioxidant capacity even after 8 days. Additionally, the presence of curcumin provided the film with pH indicating ability and delayed pork spoilage. Therefore, this work provides an attractive strategy for constructing green, active, and smart biomass packaging films for meat packaging applications.
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  • 文章类型: Journal Article
    这项研究的目的是开发新的废弃的enoki蘑菇根衍生的多功能无铬壳聚糖鞣剂,可用于生态皮革制造。在这项研究中,从金针菇中提取的壳聚糖制备了低聚壳聚糖(OCS),并使用活性染料R19和表氯醇(ECH)进行化学改性,以制备具有鞣制和染色功能的无铬鞣剂(OCS-R19-ECH)。FT-IR,XRD,和NMR(1H)证实了产物的成功合成。OCS-R19-ECH的分子量为6355g/mol,平均粒径为1249.37nm,环氧值为0.276mol/100g。OCS-R19-ECH用于在贝特羊皮上进行鞣制实验,结果表明,用OCS-R19-ECH鞣制的皮革不仅表现出优异的湿热稳定性(收缩温度=81℃),而且染色均匀性优越,耐干和湿磨损,机械强度(抗拉强度=12.4MPa,撕裂强度=57.3N/mm),和突出的抗菌性能。最重要的是,与传统鞣剂相比,OCS-R19-ECH具有较高的pH(9.0),鞣染一体化,非酸浸泡,在皮革制造中可以实现非碱化,这可以大大简化鞣制过程。这种新型多功能无铬壳聚糖基鞣剂促进了废弃资源的高价值利用。
    The aim of this study was to develop new discarded enoki mushroom root-derived multifunctional chrome-free chitosan-based tanning agents that can be used for eco-leather manufacturing. In this study, oligochitosan (OCS) was prepared from chitosan extracted from the enoki mushrooms and chemically modified using reactive dye R19 and epichlorohydrin (ECH) to prepare chromium-free tanning agent (OCS-R19-ECH) with both tanning and dyeing functions. FT-IR, XRD, and NMR (1H) confirmed the successful synthesis of the product. The molecular weight of OCS-R19-ECH is 6355 g/mol, with an average particle size of 1249.37 nm and an epoxy value of 0.276 mol/100 g. OCS-R19-ECH was used for tanning experiments on bated sheepskin, and the results showed that the leather tanned with OCS-R19-ECH not only exhibited excellent wet-heat stability (shrinkage temperature = 81 °C), but also superior dyeing uniformity, resistance to dry and wet abrasion, mechanical strength (tensile strength = 12.4 MPa, tear strength = 57.3 N/mm), and outstanding antimicrobial properties. Most importantly, compared with traditional tanning agents, OCS-R19-ECH has a higher pH (9.0), tanning-dyeing integration, non-acid soaking, and non-basifying can be achieved in leather making, which can greatly simplify the tanning processes. This new multifunctional chrome-free chitosan-based tanning agent facilitates high-value utilization of waste resources.
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