• 【硅灰石纳米纤维掺杂自凝磷酸钙生物活性水泥用于骨组织再生。】 复制标题 收藏 收藏
    DOI:10.2147/IJN.S32061 复制DOI
    作者列表:Guo H,Wei J,Song W,Zhang S,Yan Y,Liu C,Xiao T
    BACKGROUND & AIMS: :The purpose of this study was to synthesize a self-setting bioactive cement by incorporation of wollastonite nanofibers (WNFs) into calcium phosphate cement (CPC). The composition, morphology, setting time, compressive strength, hydrophilicity, and degradation of WNF-doped CPC (wnf-CPC) were investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and inductively coupled plasma atomic emission spectroscopy were utilized. Additionally, methyl-thiazolyl-tetrazolium bromide assay, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, and histological evaluation were used to study the cell and tissue responses to wnf-CPC, both in vitro and in vivo. The results confirmed that the addition of WNFs into CPC had no obvious effect on the setting time or the compressive strength of wnf-CPC, provided the WNF amount was not more than 10 wt%. However, the hydrophilicity and degradability of wnf-CPC were significantly improved by the addition of WNFs - this was because of the change of microstructure caused by the WNFs. The preferred dissolution of WNFs caused the formation of microporosity in wnf-CPC when soaked in tris hydrochloride solution. The microporosity enlarged the surface area of the wnf-CPC and so promoted degradation of the wnf-CPC when in contact with liquid. In addition, MG-63 cell attachment and proliferation on the wnf-CPC were superior to that on the CPC, indicating that incorporation of WNFs into CPC improved the biological properties for wnf-CPC. Following the implantation of wnf-CPC into bone defects of rabbits, histological evaluation showed that wnf-CPC enhanced the efficiency of new bone formation in comparison with CPC, indicating excellent biocompatibility and osteogenesis of wnf-CPC. In conclusion, wnf-CPC exhibited promising prospects in bone regeneration.
    背景与目标: : 这项研究的目的是通过将硅灰石纳米纤维 (WNFs) 掺入磷酸钙水泥 (CPC) 中来合成自固化的生物活性水泥。研究了WNF掺杂的CPC (wnf-CPC) 的组成,形态,凝固时间,抗压强度,亲水性和降解。利用扫描电子显微镜,傅立叶变换红外光谱,x射线衍射和电感耦合等离子体原子发射光谱。此外,还使用甲基-噻唑基-溴化四唑鎓测定,扫描电子显微镜,电感耦合等离子体原子发射光谱和组织学评估来研究细胞和组织对wnf-CPC的体外和体内反应。结果证实,在CPC中添加WNFs对wnf-CPC的凝结时间或抗压强度没有明显影响,前提是WNF含量不超过10 wt %。然而,通过添加WNFs,wnf-CPC的亲水性和可降解性得到了显着改善-这是由于WNFs引起的微观结构变化。当浸泡在tris盐酸盐溶液中时,WNFs的优选溶解导致wnf-CPC中形成微孔。微孔扩大了wnf-CPC的表面积,因此在与液体接触时促进了wnf-CPC的降解。此外,MG-63细胞在wnf-CPC上的附着和增殖优于CPC,表明将WNFs掺入CPC中改善了wnf-CPC的生物学特性。将wnf-CPC植入兔骨缺损后,组织学评估表明,与CPC相比,wnf-CPC增强了新骨形成的效率,表明wnf-CPC具有出色的生物相容性和成骨作用。总之,wnf-CPC在骨再生方面具有广阔的前景。
  • 【基于全纳米纤维、超灵敏、透气的机械声传感器,用于连续长期心脏监测。】 复制标题 收藏 收藏
    DOI:10.1073/pnas.1920911117 复制DOI
    作者列表:Nayeem MOG,Lee S,Jin H,Matsuhisa N,Jinno H,Miyamoto A,Yokota T,Someya T
    BACKGROUND & AIMS: :The prolonged and continuous monitoring of mechanoacoustic heart signals is essential for the early diagnosis of cardiovascular diseases. These bodily acoustics have low intensity and low frequency, and measuring them continuously for long periods requires ultrasensitive, lightweight, gas-permeable mechanoacoustic sensors. Here, we present an all-nanofiber mechanoacoustic sensor, which exhibits a sensitivity as high as 10,050.6 mV Pa-1 in the low-frequency region (<500 Hz). The high sensitivity is achieved by the use of durable and ultrathin (2.5 µm) nanofiber electrode layers enabling a large vibration of the sensor during the application of sound waves. The sensor is ultralightweight, and the overall weight is as small as 5 mg or less. The devices are mechanically robust against bending, and show no degradation in performance even after 1,000-cycle bending. Finally, we demonstrate a continuous long-term (10 h) measurement of heart signals with a signal-to-noise ratio as high as 40.9 decibels (dB).
    背景与目标: : 长期和连续监测机械声学心脏信号对于心血管疾病的早期诊断至关重要。这些身体声学具有低强度和低频,并且长时间连续测量它们需要超灵敏,轻巧,透气的机械声学传感器。在这里,我们提出了一种全纳米纤维机械声传感器,该传感器在低频区域 (<500Hz) 表现出高达10,050.6 mV Pa-1的灵敏度。通过使用耐用且超薄 (2.5 µ m) 的纳米纤维电极层来实现高灵敏度,从而在声波施加期间能够使传感器产生较大的振动。传感器是超轻的,总重量小到5毫克或更少。该装置在机械上是抗弯曲的,并且即使在1,000循环弯曲之后也不会显示性能下降。最后,我们证明了对心脏信号的连续长期 (10 h) 测量,其信噪比高达40.9分贝 (dB)。
  • 【用蒸气生长的碳纳米纤维对大鼠进行的90天吸入毒性研究。】 复制标题 收藏 收藏
    DOI:10.1093/toxsci/kfs172 复制DOI
    作者列表:Delorme MP,Muro Y,Arai T,Banas DA,Frame SR,Reed KL,Warheit DB
    BACKGROUND & AIMS: :A subchronic inhalation toxicity study of inhaled vapor grown carbon nanofibers (CNF) (VGCF-H) was conducted in male and female Sprague Dawley rats. The CNF test sample was composed of > 99.5% carbon with virtually no catalyst metals; Brunauer, Emmett, and Teller (BET) surface area measurements of 13.8 m2/g; and mean lengths and diameters of 5.8 µm and 158 nm, respectively.Four groups of rats per sex were exposed nose-only, 6 h/day, for 5 days/week to target concentrations of 0, 0.50, 2.5, or 25 mg/m3 VGCF-H over a 90-day period and evaluated 1 day later. Assessments included conventional clinical and histopathological methods, bronchoalveolar lavage fluid (BALF) analysis, and cell proliferation (CP) studies of the terminal bronchiole (TB), alveolar duct (AD), and subpleural regions of the respiratory tract. In addition, groups of 0 and 25 mg/m3 exposed rats were evaluated at 3 months postexposure (PE). Aerosol exposures of rats to 0.54 (4.9 f/cc), 2.5 (56 f/cc), and 25 (252 f/cc) mg/m(3) of VGCF-H CNFs produced concentration-related small, detectable accumulation of extrapulmonary fibers with no adverse tissue effects. At the two highest concentrations, inflammation of the TB and AD regions of the respiratory tract was noted wherein fiber-laden alveolar macrophages had accumulated. This finding was characterized by minimal infiltrates of inflammatory cells in rats exposed to 2.5mg/m(3) CNF, inflammation along with some thickening of interstitial walls, and hypertrophy/hyperplasia of type II epithelial cells, graded as slight for the 25mg/m(3) concentration. At 3 months PE, the inflammation in the high dose was reduced. No adverse effects were observed at 0.54mg/m(3). BALF and CP endpoint increases versus controls were noted at 25mg/m(3) VGCF-H but not different from control values at 0.54 or 2.5mg/m(3). After 90 days PE, BALF biomarkers were still increased at 25mg/m(3), indicating that the inflammatory response was not fully resolved. Greater than 90% of CNF-exposed, BALF-recovered alveolar macrophages from the 25 and 2.5mg/m(3) exposure groups contained nanofibers (> 60% for 0.5mg/m(3)). A nonspecific inflammatory response was also noted in the nasal passages. The no-observed-adverse-effect level for VGCF-H nanofibers was considered to be 0.54mg/m(3) (4.9 fibers/cc) for male and female rats, based on the minimal inflammation in the terminal bronchiole and alveolar duct areas of the lungs at 2.5mg/m(3) exposures. It is noteworthy that the histopathology observations at the 2.5mg/m(3) exposure level did not correlate with the CP or BALF data at that exposure concentration. In addition, the results with CNF are compared with published findings of 90-day inhalation studies in rats with carbon nanotubes, and hypotheses are presented for potency differences based on CNT physicochemical characteristics. Finally, the (lack of) relevance of CNF for the high aspect ratio nanomaterials/fiber paradigm is discussed.
    背景与目标: : 在雄性和雌性Sprague Dawley大鼠中进行了吸入蒸气生长的碳纳米纤维 (CNF) (vgcf-h) 的亚慢性吸入毒性研究。CNF测试样品由> 99.5% 碳组成,几乎没有催化剂金属; Brunauer,Emmett和Teller (BET) 的表面积测量值为13.8平方米/g; 平均长度和直径分别为5.8微米和158纳米。6 h/天,持续5天/周,在90天期间达到0、0.50、2.5或25 mg/m3 VGCF-H的目标浓度,并在1天后评估。评估包括常规的临床和组织病理学方法,支气管肺泡灌洗液 (BALF) 分析以及末端细支气管 (TB),肺泡管 (AD) 和呼吸道胸膜下区域的细胞增殖 (CP) 研究。此外,在暴露后3个月 (PE) 评估0和25 mg/m3暴露大鼠组。大鼠气溶胶暴露于0.54 (4.9 f/cc) 、2.5 (56 f/cc) 和25 (252 f/cc) mg/m(3) 的VGCF-H CNFs产生与浓度相关的小的可检测的肺外纤维蓄积,没有不良组织影响。在两个最高浓度下,注意到TB和AD呼吸道区域的炎症,其中富含纤维的肺泡巨噬细胞已经积累。该发现的特征是暴露于2.5 mg/m(3) CNF的大鼠中炎症细胞的最小浸润,炎症以及间质壁的一些增厚以及II型上皮细胞的肥大/增生,对于25 mg/m(3) 浓度而言是轻微的。在3个月的PE时,高剂量的炎症减少。在0.54 mg/m(3) 下未观察到不良反应。在25 mg/m(3) VGCF-H时,BALF和CP端点相对于对照增加,但与0.54或2.5 mg/m(3) 时的对照值没有差异。PE 90天后,BALF生物标志物仍在25 mg/m(3) 处增加,表明炎症反应尚未完全解决。来自25和2.5 mg/m(3) 暴露组的大于90% 的CNF暴露、BALF回收的肺泡巨噬细胞含有纳米纤维 (> 60% 0.5 mg/m(3))。在鼻腔中也发现了非特异性炎症反应。基于终末细支气管和肺泡管区域的最小炎症,对于雄性和雌性大鼠,VGCF-H纳米纤维的未观察到的不良反应水平被认为是0.54 mg/m(3) (4.9纤维/cc)。在2.5 mg/m(3) 暴露下的肺的区域。值得注意的是,在2.5mg/m(3) 暴露水平下的组织病理学观察与该暴露浓度下的CP或BALF数据不相关。此外,将CNF的结果与碳纳米管大鼠90天吸入研究的公开结果进行了比较,并提出了基于CNT理化特性的效力差异假设。最后,讨论了CNF与高纵横比纳米材料/纤维范例的 (缺乏) 相关性。
  • 【钼酸铋结合了功能化的碳纳米纤维,作为电催化工具,用于精确检测生命样品中的有机污染物。】 复制标题 收藏 收藏
    DOI:10.1016/j.ecoenv.2020.111828 复制DOI
    作者列表:Krishnapandi A,Muthukutty B,Chen SM,Arul KT,Shiuan HJ,Selvaganapathy M
    BACKGROUND & AIMS: :Herein, we fabricated a feasible and accurate sensing platform for the quantification of toxic organic pollutant 2-nitroaniline (2-NA) in water samples through electrocatalyst made up of bismuth molybdate (Bi2MoO6, BMO) functionalized carbon nanofiber (f-CNF) modified electrode. The preparation of BMO/f-CNF composite is of two methods, such as co-precipitation (C-BMO/f-CNF) and ultrasonication method (U-BMO/f-CNF). The physicochemical properties of the composites were characterized by XRD, FTIR, Raman, BET, FE-SEM, and HR-TEM techniques. At U-BMO/f-CNF, the charge transfer resistance was low (Rct = 12.47 Ω) compared to C-BMO/f-CNF because nanosized U-BMO particles correctly aim at the defective sites of the f-CNF surface wall. Further, the electrocatalytic activity of C&U-BMO/f-CNF composites was examined by cyclic voltammetry (CV) and differential pulse voltammetry techniques (DPV) for the electrochemical detection of 2-nitroaniline (2-NA). The U-BMO/f-CNF/GCE shows a higher cathodic current, wide dynamic linear range of 0.01-168.01 µM, and superior electrocatalytic activity with a low detection limit (0.0437 µM) and good sensitivity (0.6857 μA μM-1 cm-2). The excellent selectivity nature of U-BMO/f-CNF/GCE was observed in the presence of various organic pollutants and a few toxic metal cations. The practical applicability such as stability, repeatability towards 2-NA outcomes with accepted results. Besides, the practical viability of as proposed U-BMO/f-CNF sensor was investigated in soil and lake water samples delivers good recovery results. Hence from these analyses, we conclude that U-BMO/f-CNF/GCE potential for the determination of hazardous environmental pollutant 2-NA.
    背景与目标: : 在此,我们通过由钼酸铋 (Bi2MoO6,BMO) 功能化的碳纳米纤维 (f-cnf) 修饰电极组成的电催化剂,制造了一种可行且准确的传感平台,用于定量水样中的有毒有机污染物2-硝基苯胺 (2-NA)。BMO/f-cnf复合材料的制备有两种方法,如共沉淀法 (c-bmo/f-cnf) 和超声法 (U-BMO/f-cnf)。通过XRD,FTIR,Raman,BET,fe-sem和hr-tem技术对复合材料的理化性能进行了表征。在U-BMO/f-CNF处,与C-BMO/f-CNF相比,电荷转移电阻低 (Rct = 12.47 Ω),因为纳米尺寸的U-BMO颗粒正确地瞄准了f-cnf表面壁的缺陷部位。此外,通过循环伏安 (CV) 和差分脉冲伏安技术 (DPV) 检查了C & U-BMO/f-CNF复合材料的电催化活性,用于2-硝基苯胺 (2-NA) 的电化学检测。U-BMO/f-CNF/GCE显示出更高的阴极电流,0.01-168.01 µ m的宽动态线性范围以及优异的电催化活性,具有低检出限 (0.0437 µ m) 和良好的灵敏度 (0.6857 μ a μ m-1 cm-2)。在存在各种有机污染物和一些有毒金属阳离子的情况下,观察到U-BMO/f-CNF/GCE的优异选择性。实际适用性,如稳定性、对2-NA结果的可重复性和公认的结果。此外,还研究了所提出的U-BMO/f-CNF传感器在土壤和湖水样品中的实际可行性,并提供了良好的回收效果。因此,从这些分析中,我们得出结论,U-BMO/f-CNF/GCE在测定危险环境污染物2-NA方面的潜力。
  • 【对齐的纳米纤维导管在大鼠坐骨神经疼痛神经瘤管理中的作用。】 复制标题 收藏 收藏
    DOI:10.1097/SAP.0000000000000266 复制DOI
    作者列表:Yan H,Zhang F,Wang C,Xia Z,Mo X,Fan C
    BACKGROUND & AIMS: BACKGROUND:Capping techniques have been used as a treatment modality for the prevention of neuroma formation and the management of neuropathic pain. However, the results are inconsistent and unpredictable. We hypothesize that this situation may be attributable, in part, to the disparities in the type of materials used to manufacturing of the conduits. METHODS:In this study, a rat model was used and the sciatic nerve was selected for evaluation. In 1 capping group, a sciatic nerve stump was capped with a nonaligned nanofiber conduit (the nonaligned group), whereas in a second capping group, the conduit was made of aligned nanofibers (the aligned group). In another group, the sciatic nerve stump was not capped as a control (the control group). The results of autotomy behavior, extent of neuroma formation, histological changes in the neuroma, and the expression of c-fos as a pain marker in the fourth lumbar spinal cord were evaluated at 8 weeks postoperatively. RESULTS:The control group presented more neuroma-like features in all the observed parameters in comparison with the 2 capping groups; of the 2 capping groups, the aligned group achieved even better outcomes than the nonaligned group. CONCLUSIONS:Our findings indicate that the aligned nanofiber conduit is a promising biomaterial for the nerve capping technique, and new treatment strategies using aligned nanofiber conduits may be developed for the management of painful amputated neuromas.
    背景与目标:
  • 【纤维素纳米纤维背骨普鲁士蓝纳米粒子作为选择性消除放射性铯的强大吸附剂。】 复制标题 收藏 收藏
    DOI:10.1038/srep37009 复制DOI
    作者列表:Vipin AK,Fugetsu B,Sakata I,Isogai A,Endo M,Li M,Dresselhaus MS
    BACKGROUND & AIMS: :On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi's damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (106) order of magnitude distribution coefficient (Kd) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications.
    背景与目标: : 2011年3月11日,这是东北9级地震令人难忘的灾难的一天,随后又发生了毁灭性的海啸,福岛第一核电站受损的核反应堆中散布了可破坏的放射性核素。由于大量具有竞争性功能的共存离子,海水和土壤中分散的放射性核素的去污一直是最困难的。六氰铁酸铁,也称为普鲁士蓝 (PB),是选择性捕获放射性铯离子的最强大的材料; 但是,它在水中形成稳定胶体的高度趋势使PB无法用于露天放射性铯净化应用。如本研究中所述,纳米/纳米组合方法为PB的这种固有胶体形成困难提供了最终解决方案。纤维素纳米纤维 (CNF) 通过产生CNF背结的PB来固定PB。发现CNF背结PB (CNF/PB) 对水具有高度耐受性,此外,它具有139的  mg/g能力和百万 (106) 数量级的分布系数 (Kd) 吸收放射性铯离子。福岛土壤和海水净化的现场研究取得了令人满意的结果,证明了CNF/PB在实际应用中的强大能力。
  • 【评估结合Zataria multiflora精油作为潜在伤口敷料的电纺聚乙烯醇基纳米纤维垫。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijbiomac.2018.12.085 复制DOI
    作者列表:Ardekani NT,Khorram M,Zomorodian K,Yazdanpanah S,Veisi H,Veisi H
    BACKGROUND & AIMS: :Infections, especially those caused by multi-drug resistant pathogens, result in serious problems in wound healing process. In this study, Zataria multiflora (ZM) essential oil, as a strong natural antimicrobial agent, is incorporated into poly (vinyl alcohol)-based nanofiber mats to fabricate a novel wound dressing. Different amounts of ZM essential oil (0, 2, 5 and 10% (v/v)) were incorporated into chitosan/poly(vinyl alcohol)/gelatin (CS/PVA/Gel) solutions and then were successfully electrospun into beadless and uniform fibers with 95 ± 14, 154 ± 27, 187 ± 40 and 218 ± 58 nm in diameters, respectively. The produced nanofiber mats (CS/PVA/Gel/ZM) were chemically crosslinked by glutaraldehyde vapor. The chemical compositions of ZM essential oil and nanofiber mats were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. The antimicrobial activity of the CS/PVA/Gel/ZM nanofiber mats was determined by the AATCC100 method. The nanofiber mat loaded with 10% of ZM essential oil completely inhibited the growth of Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans after 24 h of incubation. Swelling investigations showed that the produced nanofibers have a substantial ability to take up water, in the range of 400-900%. Mechanical properties of the nanofiber mats were studied by tensile testing. Furthermore, they were found to be non-toxic by biocompatibility assays on mouse fibroblast (L929) cells. The obtained results have demonstrated that CS/PVA/Gel nanofiber mats, loaded with ZM essential oil, are promising alternatives to conventional wound dressings.
    背景与目标: : 感染,尤其是由多重耐药病原体引起的感染,导致伤口愈合过程中出现严重问题。在这项研究中,Zataria multiflora (ZM) 精油作为一种强天然抗菌剂,被掺入基于聚乙烯醇的纳米纤维垫中,以制造一种新型的伤口敷料。将不同量的ZM精油 (0、2、5和10% (v/v)) 掺入壳聚糖/聚乙烯醇/明胶 (CS/PVA/Gel) 溶液中,然后以95   ±   14成功地电纺丝成无珠均匀纤维,直径分别为154   ±   27、187   ±   40和218   ±   58  nm。所产生的纳米纤维垫 (CS/PVA/Gel/ZM) 通过戊二醛蒸气化学交联。分别使用气相色谱-质谱 (gc-ms) 和傅里叶变换红外光谱 (FTIR) 分析了ZM精油和纳米纤维毡的化学成分。通过AATCC100方法测定了CS/PVA/Gel/ZM纳米纤维垫的抗菌活性。10% ZM精油的纳米纤维垫在培养24小时后完全抑制金黄色葡萄球菌、铜绿假单胞菌和白色念珠菌的生长。溶胀研究表明,所产生的纳米纤维具有在400-900% 范围内吸收水的显著能力。通过拉伸测试研究了纳米纤维垫的机械性能。此外,通过对小鼠成纤维细胞 (L929) 细胞的生物相容性测定,发现它们是无毒的。获得的结果表明,装有ZM精油的CS/PVA/凝胶纳米纤维垫有望替代常规伤口敷料。
  • 【使用离子液体的溶剂焊接和压印纤维素纳米纤维薄膜。】 复制标题 收藏 收藏
    DOI:10.1021/acs.biomac.8b01554 复制DOI
    作者列表:Reyes G,Borghei M,King AWT,Lahti J,Rojas OJ
    BACKGROUND & AIMS: :Cellulose nanofiber films (CNFF) were treated via a welding process using ionic liquids (ILs). Acid-base-conjugated ILs derived from 1,5-diazabicyclo[4.3.0]non-5-ene [DBN] and 1-ethyl-3-methylimidazolium acetate ([emim][OAc]) were utilized. The removal efficiency of ILs from welded CNFF was assessed using liquid-state nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The mechanical and physical properties of CNFF indicated surface plasticization of CNFF, which improved transparency. Upon treatment, the average CNFF toughness increased by 27%, and the films reached a Young's modulus of ∼5.8 GPa. These first attempts for IL "welding" show promise to tune the surfaces of biobased films, expanding the scope of properties for the production of new biobased materials in a green chemistry context. The results of this work are highly relevant to the fabrication of CNFFs using ionic liquids and related solvents.
    背景与目标: : 使用离子液体 (ILs) 通过焊接工艺处理纤维素纳米纤维膜 (CNFF)。使用衍生自1,5-二氮杂双环 [4.3.0]non-5-ene [DBN] 和1-乙基-3-甲基咪唑鎓乙酸酯 ([emim][OAc]) 的酸碱共轭il。使用液态核磁共振 (NMR) 光谱和傅里叶变换红外光谱 (FTIR) 评估了焊接CNFF中ILs的去除效率。CNFF的机械和物理性能表明CNFF的表面塑化,从而提高了透明度。处理后,平均CNFF韧性增加27%,并且薄膜达到约5.8 GPa的杨氏模量。IL “焊接” 的这些首次尝试显示出有望调整生物基膜的表面,从而扩大了在绿色化学背景下生产新生物基材料的性能范围。这项工作的结果与使用离子液体和相关溶剂制造CNFFs高度相关。
  • 【用于控制释放的自组装肽纳米纤维支架受胶凝剂设计和客体尺寸的控制。】 复制标题 收藏 收藏
    DOI:10.1016/j.jconrel.2010.08.002 复制DOI
    作者列表:Zhao Y,Tanaka M,Kinoshita T,Higuchi M,Tan T
    BACKGROUND & AIMS: :The aim of this study was to develop controlled drug delivery by network scaffolds based on self-assembling peptide RADAFI and RADAFII. These two peptides self-assembled into interconnected nanofibrilar network structures with distinct physical morphologies. The hydrogels were also utilized for entrapment and release of some model guests, promising their future application as a drug delivery vehicle. Fickian diffusion controlled the release kinetics. Furthermore, the obtained release function was dependent on both rational design of the peptides used for hydrogel formation and choice of the entrapped molecules. On the basis of the striking different releases of these two peptide scaffolds, we suggested that guest size and lipophilicity influenced the release competitively. The release of RADAFI system was dominated by guest size, and the guest lipophilicity controlled the release behavior in RADAFII system. In a word, this work would potentially provide a spatially and temporally controlled delivery system for some functional drugs in the future.
    背景与目标: : 这项研究的目的是开发基于自组装肽RADAFI和RADAFI的网络支架的受控药物递送。这两种肽自组装成具有不同物理形态的相互连接的纳米纤维网络结构。水凝胶还用于捕获和释放某些模型来宾,并有望将其作为药物输送载体。Fickian扩散控制了释放动力学。此外,获得的释放功能取决于用于水凝胶形成的肽的合理设计和截留分子的选择。基于这两种肽支架的显着不同释放,我们建议客体大小和亲脂性竞争性地影响释放。RADAFI系统的释放主要由来宾大小主导,来宾亲脂性控制了RADAFI系统的释放行为。总之,这项工作可能会在将来为某些功能药物提供空间和时间控制的递送系统。
  • 【使用尼龙6,6纳米纤维膜处理微藻过滤中的膜污染。】 复制标题 收藏 收藏
    DOI:10.1016/j.jenvman.2018.06.007 复制DOI
    作者列表:Bilad MR,Azizo AS,Wirzal MDH,Jia Jia L,Putra ZA,Nordin NAHM,Mavukkandy MO,Jasni MJF,Yusoff ARM
    BACKGROUND & AIMS: :Microalgae technology, if managed properly, has promising roles in solving food-water-energy nexus. The Achilles' heel is, however, to lower the costs associated with cultivation and harvesting. As a favorable technique, application of membrane process is strongly limited by membrane fouling. This study evaluates performance of nylon 6,6 nanofiber membrane (NFM) to a conventional polyvinylidene fluoride phase inverted membrane (PVDF PIM) for filtration of Chlorella vulgaris. Results show that nylon 6,6 NFM is superhydrophilic, has higher size of pore opening (0.22 vs 0.18 μm) and higher surface pore density (23 vs 18 pores/μm2) leading to higher permeance (1018 vs 493 L/m2hbar) and better fouling resistant. Such advantages help to outperform the filterability of PVDF PIM by showing much higher steady-state permeance (286 vs 120 L/m2hbar), with comparable biomass retention. In addition, unlike for PVDF PIM, imposing longer relaxation cycles further enhances the performance of the NFM (i.e., 178 L/m2hbar for 0.5 min and 236 L/m2hbar for 5 min). Overall findings confirm the advantages of nylon 6,6 NFM over the PVDF PIM. Such advantages can help to reduce required membrane area and specific aeration demand by enabling higher flux and lowering aeration rate. Nevertheless, developments of nylon 6,6 NFM material with respect to its intrinsic properties, mechanical strength and operational conditions of the panel can still be explored to enhance its competitiveness as a promising fouling resistant membrane material for microalgae filtration.
    背景与目标: : 微藻技术,如果管理得当,在解决食物-水-能源关系方面具有广阔的作用。然而,致命弱点是为了降低与种植和收获相关的成本。作为一种有利的技术,膜工艺的应用受到膜污染的强烈限制。这项研究评估了尼龙6,6纳米纤维膜 (NFM) 在常规聚偏氟乙烯相倒置膜 (PVDF PIM) 上的性能,以过滤普通小球藻。结果表明,尼龙6,6 NFM是超亲水的,具有较高的孔开口尺寸 (0.22对0.18  μ m) 和较高的表面孔密度 (23对18孔/μ m2),导致更高的渗透率 (1018对493 L/m2hbar) 和更好的抗污垢性能。这些优点通过显示出高得多的稳态渗透率 (286相对于120 L/m2hbar),具有相当的生物量保留率,有助于优于PVDF PIM的过滤性。此外,与PVDF PIM不同,施加更长的弛豫周期进一步增强NFM的性能 (即,178  L/m2hbar为0.5  min,236  L/m2hbar为5  min)。总体发现证实了尼龙6,6 NFM优于PVDF PIM的优势。这些优点可以通过实现更高的通量和降低曝气速率来帮助减少所需的膜面积和特定的曝气需求。尽管如此,仍可以探索尼龙6,6 NFM材料在其固有性能、机械强度和面板操作条件方面的发展,以增强其作为用于微藻过滤的有希望的抗污染膜材料的竞争力。
  • 【基于实时厚度测量的均匀厚度电纺纳米纤维毡生产系统】 复制标题 收藏 收藏
    DOI:10.1038/s41598-020-77985-0 复制DOI
    作者列表:Ryu HI,Koo MS,Kim S,Kim S,Park YA,Park SM
    BACKGROUND & AIMS: :Electrospinning is a simple versatile process used to produce nanofibers and collect them as a nanofiber mat. However, due to bending instability, electrospinning often produces a nanofiber mat with non-uniform mat thickness. In this study, we developed a uniform-thickness electrospun nanofiber mat (UTEN) production system with a movable collector based on real-time thickness measurement and thickness feedback control. This system is compatible with a collector with void regions such as a mesh-type collector, two-parallel-metal-plate collector, and ring-type collector, which facilitates the measurement of light transmittance across the produced nanofiber mat during electrospinning. A real-time measurement system was developed to measure light transmittance and convert it to the thickness of the nanofiber mat in real time using the Beer-Lambert law. Thickness feedback control was achieved by repeating the following sequences: (1) finding an optimal position of the movable collector based on the measured thickness of the nanofiber mat, (2) shifting the collector to an optimal position, and (3) performing electrospinning for a given time step. We found that the suggested thickness feedback control algorithm could significantly decrease the non-uniformity of the nanofiber mat by reducing the standard deviation by more than 8 and 3 times for the numerical simulation and experiments, respectively, when compared with the conventional electrospinning. As a pioneering research, this study will contribute to the development of an electrospinning system to produce robust and reliable nanofiber mats in many research and industrial fields such as biomedicine, environment, and energy.
    背景与目标: : 静电纺丝是一种简单的通用工艺,用于生产纳米纤维并将其收集为纳米纤维垫。然而,由于弯曲不稳定性,静电纺丝通常会产生厚度不均匀的纳米纤维毡。在这项研究中,我们基于实时厚度测量和厚度反馈控制,开发了具有可移动收集器的均匀厚度电纺纳米纤维毡 (UTEN) 生产系统。该系统与具有空隙区域的收集器兼容,例如网状收集器,两个平行金属板收集器和环形收集器,这有助于在静电纺丝过程中测量整个纳米纤维毡的透光率。开发了一种实时测量系统,用于测量透光率并使用比尔-兰伯特定律将其实时转换为纳米纤维垫的厚度。通过重复以下顺序来实现厚度反馈控制 :( 1) 基于测量的纳米纤维垫的厚度找到可移动收集器的最佳位置,(2) 将收集器移动到最佳位置,以及 (3) 在给定的时间步长内进行静电纺丝。我们发现,与传统的静电纺丝相比,建议的厚度反馈控制算法通过将标准偏差分别降低8倍和3倍以上,可以显着降低纳米纤维毡的不均匀性。作为一项开创性的研究,这项研究将有助于开发一种静电纺丝系统,以在许多研究和工业领域 (例如生物医学,环境和能源) 中生产坚固可靠的纳米纤维毡。
  • 【马来酸酐电纺纳米纤维毡接枝聚对苯二甲酸乙二醇酯漆酶固定化的优化策略。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijbiomac.2020.10.244 复制DOI
    作者列表:Mohd Syukri MS,A Rahman R,Mohamad Z,Md Illias R,Nik Mahmood NA,Jaafar NR
    BACKGROUND & AIMS: :Enzyme immobilization has been known to be one of the methods to improve the stability and reusability of enzyme. In this study, a strategy to optimize laccase immobilization on polyethylene terephthalate grafted with maleic anhydride electrospun nanofiber mat (PET-g-MAH ENM) was developed. The development involves the screening and optimization processes of the crucial factors that influence the immobilization yield such as enzyme concentration, pH values, covalent bonding (CV) time, CV temperature, crosslinking (CL) time, CL temperature and glutaraldehyde concentration using two-level factorial design and Box-Behnken design (BBD), respectively. It was found that laccase concentration, pH values and glutaraldehyde concentration play important role in enhancing the immobilization yield of laccase on PET-g-MAH ENM in the screening process. Subsequently, the optimization result showed at 0.28 mg/ml laccase concentration, pH 3 and 0.45% (v/v) glutaraldehyde concentrations gave the highest immobilization yield at 87.64% which was 81.2% increment from the immobilization yield before optimization. Under the optimum condition, the immobilized laccase was able to oxidize 2, 2-azino-bis 3-ethylbenzothiazoline-6- sulfonic acid (ABTS) in a broad range of pH (pH 3-6) and temperature (20- 70 °C). Meanwhile, the kinetic parameters for Km and Vmax were 1.331 mM and 0.041 mM/min, respectively. It was concluded that the optimization of immobilized laccase on PET-g-MAH ENM enhance the performance of this biocatalyst.
    背景与目标: : 酶固定化已被认为是提高酶的稳定性和可重复使用性的方法之一。在这项研究中,开发了一种优化在马来酸酐电纺纳米纤维毡 (PET-g-MAH ENM) 接枝的聚对苯二甲酸乙二醇酯上固定漆酶的策略。该开发涉及影响固定化产率的关键因素的筛选和优化过程,例如酶浓度,ph值,共价键合 (CV) 时间,CV温度,交联 (CL) 时间,CL温度和戊二醛浓度分别采用二级析因设计和Box-Behnken设计 (BBD)。研究发现,在筛选过程中,漆酶浓度,ph值和戊二醛浓度对提高漆酶在PET-g-MAH ENM上的固定化率具有重要作用。随后,优化结果显示在0.28 mg/ml漆酶浓度下,pH 3和0.45% (v/v) 戊二醛浓度在87.64% 时给出了最高的固定化产率,比优化前的固定化产率增加了81.2%。在最佳条件下,固定化的漆酶能够在较宽的pH (pH 3-6) 和温度 (20- 70 °C) 范围内氧化2,2-氮杂-双3-乙基苯并噻唑啉-6-磺酸 (ABTS)。同时,Km和Vmax的动力学参数分别为1.331 mM和0.041 mM/min。结论是,在PET-g-MAH ENM上固定化漆酶的优化可增强该生物催化剂的性能。
  • 【用于组织再生的电纺大豆蛋白纳米纤维支架。】 复制标题 收藏 收藏
    DOI:10.1177/0885328214530765 复制DOI
    作者列表:Ramji K,Shah RN
    BACKGROUND & AIMS: :Electrospun fibers with an average fiber diameter in the nanometer range were prepared from soy protein isolate to develop scaffolds for tissue engineering applications. Poly(ethylene oxide) was added to facilitate fiber formation. The influence of processing parameters such as applied voltage, soy protein isolate and poly(ethylene oxide) concentrations, and poly(ethylene oxide) molecular weight on electrospun fiber morphology was investigated. Resulting soy protein isolate/poly(ethylene oxide) mats were carbodiimide crosslinked to increase construct robustness. Mechanical properties and in vitro biocompatibility of crosslinked electrospun scaffolds were evaluated. Soy protein isolate/poly(ethylene oxide) fiber diameters ranged between 50 and 270 nm depending on both electrospinning and solution parameters. The Young's modulus for 7% soy protein isolate/3% poly(ethylene oxide) and 12% soy protein isolate/3% poly(ethylene oxide) electrospun scaffolds were 75 and 252 kPa, respectively. Human mesenchymal stem cell studies showed successful cell adhesion and proliferation on the soy protein isolate/poly(ethylene oxide) fibers. The structural and biological properties of these soy protein isolate electrospun scaffolds suggest their potential applications in tissue engineering.
    背景与目标: : 从大豆分离蛋白制备平均纤维直径在纳米范围内的电纺纤维,以开发用于组织工程应用的支架。添加聚环氧乙烷以促进纤维形成。研究了加工参数 (例如施加电压,大豆分离蛋白和聚 (环氧乙烷) 浓度以及聚 (环氧乙烷) 分子量) 对电纺纤维形态的影响。所得的大豆分离蛋白/聚环氧乙烷垫被碳二亚胺交联以提高构建体的稳健性。评估了交联电纺支架的机械性能和体外生物相容性。大豆分离蛋白/聚环氧乙烷纤维的直径范围在50至270 nm nm之间,这取决于静电纺丝和溶液参数。7% 大豆分离蛋白/3% 聚环氧乙烷和12% 大豆分离蛋白/3% 聚环氧乙烷电纺支架的杨氏模量分别为75和252  kPa。人类间充质干细胞研究表明,大豆分离蛋白/聚环氧乙烷纤维上的细胞成功粘附和增殖。这些大豆分离蛋白电纺支架的结构和生物学特性表明了它们在组织工程中的潜在应用。
  • 【使用与纤维素纳米纤维混合的剥离膨润土的新型结构,促进不同类型的水污染物 (Cd2,番红染料和磷酸盐) 的去污。】 复制标题 收藏 收藏
    DOI:10.1016/j.jenvman.2020.111130 复制DOI
    作者列表:Abukhadra MR,Adlii A,El-Sherbeeny AM,Ahmed Soliman AT,Abd Elgawad AEE
    BACKGROUND & AIMS: :Exfoliated bentonite sheets admixed with nano-cellulose fibers (EXB/CF) were prepared as advanced bio-composite of enhanced decontamination properties for different species of water pollutants (Cd2+, safranin dye, and phosphate). The composite achieved promising adsorption capacities with experimental values of 206.8 mg/g (Cd2+), 336 mg/g (safranin), and 296 mg/g (phosphate); and predicted maximum capacities of 212.9 mg/g (Cd2+), 341 mg/g (safranin), and 305 mg/g (phosphate). The adsorption systems for the three species follow the Freundlich isotherm model and Pseudo-First order as kinetic model considering both the linear and nonlinear fitting demonstrating heterogeneous and multilayer uptake properties of physisorption type. The operation of physisorption mechanisms was supported by the obtained adsorption energies from D-R model that are less than 8 kJ/mol as well as the calculated free energies and enthalpies. The thermodynamic investigation revealed the nature of the adsorption reactions of the three pollutants by EXB/CF as exothermic, favorable, and spontaneous reactions. The EXB/CF composite also is of significant recyclability value and applied in five decontamination reusing runs for Cd2+, safranin dye, and phosphate achieving promising removal percentages.
    背景与目标: : 与纳米纤维素纤维 (EXB/CF) 混合的剥离膨润土片被制备为先进的生物复合材料,其对不同种类的水污染物 (Cd2,番红染料和磷酸盐) 具有增强的去污性能。该复合材料获得了有希望的吸附能力,实验值为206.8 mg/g (Cd2 +) 、336 mg/g (番红) 和296 mg/g (磷酸盐); 预测最大吸附能力为212.9 mg/g (Cd2 +) 、341 mg/g (番红),和305 mg/g (磷酸盐)。这三种物种的吸附系统遵循Freundlich等温线模型和伪一阶作为动力学模型,同时考虑了线性和非线性拟合,证明了物理吸附类型的异质和多层吸收特性。从d-r模型获得的小于8 kJ/mol的吸附能以及计算出的自由能和焓支持了物理吸附机制的运行。热力学研究揭示了EXB/CF对三种污染物的吸附反应的性质,它们是放热的,有利的和自发的反应。EXB/CF复合材料也具有显着的可回收性价值,可用于Cd2,番红染料和磷酸盐的五次去污再利用过程,从而实现了有希望的去除率。
  • 【GO/Bi2S3掺杂PVDF/TPU纳米纤维膜,具有增强的光热性能。】 复制标题 收藏 收藏
    DOI:10.3390/ijms21124224 复制DOI
    作者列表:Yang W,Li Y,Feng L,Hou Y,Wang S,Yang B,Hu X,Zhang W,Ramakrishna S
    BACKGROUND & AIMS: :Photothermal conversion materials have attracted wide attention due to their efficient utilization of light energy. In this study, a (GO)/Bi2S3-PVDF/TPU composite nanofiber membrane was systematically developed, comprising GO/Bi2S3 nanoparticles (NPs) as a photothermal conversion component and PVDF/TPU composite nanofibers as the substrate. The GO/Bi2S3 NPs were synthesized in a one-step way and the PVDF/TPU nanofibers were obtained from a uniformly mixed co-solution by electrospinning. GO nanoparticles with excellent solar harvesting endow the GO/Bi2S3-PVDF/TPU membrane with favorable photothermal conversion. In addition, the introduction of Bi2S3 NPs further enhances the broadband absorption and photothermal conversion properties of the GO/Bi2S3-PVDF/TPU composite membrane due to its perfect broadband absorption performance and coordination with GO. Finally, the results show that the GO/Bi2S3-PVDF/TPU composite membrane has the highest light absorption rate (about 95%) in the wavelength range of 400-2500 nm. In the 300 s irradiation process, the temperature changes in the GO/Bi2S3-PVDF/TPU composite membrane were the most significant and rapid, and the equilibrium temperature of the same irradiation time was 81 °C. Due to the presence of TPU, the mechanical strength of the composite film was enhanced, which is beneficial for its operational performance. Besides this, the morphology, composition, and thermal property of the membranes were evaluated by corresponding test methods.
    背景与目标: : 光热转换材料因其对光能的高效利用而受到广泛关注。在这项研究中,系统地开发了一种 (GO)/Bi2S3-PVDF/TPU复合纳米纤维膜,该膜包含GO/Bi2S3纳米颗粒 (NPs) 作为光热转换组分和PVDF/TPU复合纳米纤维作为基底。一步合成GO/Bi2S3 np,并通过静电纺丝从均匀混合的co溶液中获得PVDF/TPU纳米纤维。具有出色的太阳能收集的GO纳米颗粒赋予GO/Bi2S3-PVDF/TPU膜良好的光热转换。此外,Bi2S3 NPs的引入由于其完美的宽带吸收性能以及与GO的协调,进一步增强了GO/Bi2S3-PVDF/TPU复合膜的宽带吸收和光热转换性能。最后,结果表明GO/Bi2S3-PVDF/TPU复合膜在400-2500 nm波长范围内具有最高的光吸收率 (约95%)。在300 s辐照过程中,GO/Bi2S3-PVDF/TPU复合膜的温度变化最为显著和迅速,同一辐照时间的平衡温度为81 ℃。由于TPU的存在,复合膜的机械强度得到增强,这有利于其操作性能。除此之外,还通过相应的测试方法评估了膜的形态,组成和热性能。

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