负载活性组分的核壳结构纤维膜的制备及性能

采用同轴静电纺丝技术制备了用于伤口修复的核壳结构纳米纤维膜,将蛛丝蛋白(Ss)和美洲大蠊提取物(PAE)分别负载于纳米纤维的壳层与核层.采用SEM和TEM对纳米纤维膜的形貌进行了表征,结果显示,纤维具有明显的核壳结构,且随着Ss含量的增加,纤维直径从350 nm降至280 nm,核层直径由120 nm升至140 nm,壳层厚度由115 nm降至70 nm;FTIR结果证明Ss已成功负载到纤维膜中.纤维膜的物理性能测定实验表明,制备的纳米纤维膜拉伸强度可达4.3 MPa,溶胀率可达150％,水蒸气透过率可达1834 g/(m2·24 h),水接触角减小到32.7°.药物释放实验结果显示,7 d内药物释放可达77％;考察了纳米纤维膜的生物相容性,相较于未负载Ss的纳米纤维膜,Ss含量为20％的纤维膜的细胞增殖率提高了25％.     

载木犀草素纳米纤维膜的制备与性能

采用2种pH敏感材料(Eudragit S100和Eudragit RS100),通过同轴静电纺丝技术制备了壳/核结构载木犀草素纳米纤维膜,通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)等研究了壳/核结构载木犀草素纳米纤维膜的表面形貌、化学结构和药物释放性能。结果表明：壳/核结构载木犀草素纳米纤维膜表面整体较光滑,纳米纤维平均直径随木犀草素含量增加而增大。该纳米纤维膜具有良好的结肠靶向性和生物相容性。     

熔体法同轴电纺PP/(PLA+PEG)核壳超细纤维

摘要：采用自制的熔体同轴静电纺丝装置,通过控制壳层聚丙烯(PP)与核层聚乳酸(PLA)+聚乙二醇(PEG)的流量大小,制备不同直径、不同结构和不同热焓的核壳结构纤维。研究结果表明,在总流量不变的情况下,核层PLA+PEG流量增加,获得的纤维直径增大,1 g/h时平均直径为2.4 μm,5 g/h时为6 μm;PLA+PEG与PP流量相差越大,纤维直径越不均匀,内外层结构也越不均匀;PLA+PEG流量增大,制备的纤维热焓增大。为获得直径均匀、结构均匀、热焓较大的核壳结构超细纤维,PLA+PEG与PP流量比值控制在1～2倍较佳。     

同轴静电纺丝素蛋白纤维支架的制备及结构性能表征

以再生丝素蛋白水溶液为皮层纺丝液,去离子水为芯层纺丝液,探讨了同轴静电纺制备丝素蛋白组织工程支架材料的最佳工艺参数。结果表明,随着皮层纺丝液质量分数的提高,支架材料的表观形貌逐渐变好;当皮层纺丝液的质量分数为39%(w)、流速为1.2 m L/h,芯层纺丝液流速为0.3 m L/h时,可制备出表观形貌好、纤维粗细均匀且具有稳定皮芯结构的支架材料。文章探索得到的同轴静电纺丝工艺可用于载药组织工程支架材料的制备,并在组织工程修复领域具有良好的应用前景。     

新型核壳纤维增韧聚丙烯的研究

采用同轴静电纺丝技术制备聚碳酸酯为壳层,三元乙丙橡胶为核层的直径为300～600 nm的同轴纤维.将不同份数的核壳纤维与聚丙烯经过单螺杆混合,注塑后得到PP/核壳纤维复合材料.研究发现,核壳纤维用量在3份以下时,其在PP基体中的分散均匀,界面良好;核壳纤维的加入使PP的结晶速率提高,β晶含量先增大后减少;核壳纤维的用量为3份时,冲击性能较纯PP相比提高了22.17%.     

溶液参数对静电纺丝PAN@PS复合纳米纤维形貌及结构的影响

采用同轴静电纺丝技术,以聚丙烯腈(PAN)溶液为核层、聚苯乙烯(PS)溶液为壳层,制备了PAN@PS复合纳米纤维。研究了纺丝液浓度、溶剂种类对PAN@PS复合纳米纤维形貌和结构的影响。结果表明:PS/四氢呋喃(THF)作为壳层溶液的复合纳米纤维(PAN@PS/THF)可获得相界面清晰的同轴纤维。随PS纺丝液浓度的增加,纤维的直径先增大后有所减小,整体呈现递增的趋势,当PS/THF质量分数为20%时,纤维直径约为693 nm且表面光滑。而以质量分数为20%的PS/二甲基甲酰胺(DMF)为壳层溶液的复合纳米纤维(PAN@PS/DMF)直径有所增加且纤维表面凹凸不平,呈现双相连续的结构。因此,在静电纺丝过程中,可以通过改变纺丝液的参数来调节纤维的形貌和结构。     

同轴静电纺多级微纳米纤维膜的制备及其相变调温性能

为开发适宜人体温度的相变调温纺织品,采用同轴静电纺丝的方法将聚乙二醇(PEG)作为芯层封装在氮化硼(BN)增强的聚丙烯腈(PAN)壳层中,制备出氮化硼/聚丙烯腈/聚乙二醇(BN/PAN/PEG)复合相变纤维。研究了相变材料配比及BN浓度对纺丝膜形貌、热性能的影响,并对纤维膜进行热成像分析、热重分析表。结果表明:PEG1500与PEG1000-2在量比为6∶1时,复合相变材料的相变温度为36.4 ℃,满足人体温度舒适度要求;BN的质量分数为9%时,复合相变材料的热导响应性和储热效果最好。     

贵金属负载型核壳结构催化剂的制备及其催化性能

以十六烷基三甲基溴化铵(CTAB)为表面活性剂,尿素为碱源,正硅酸四乙酯(TEOS)为硅源,在环己烷和正戊醇组成的微乳体系中制备了以微孔ZSM-5分子筛为核,树枝状介孔SiO_2为壳的多级孔核壳结构分子筛。考察制备温度、时间、尿素添加量以及TEOS添加量等制备条件对制备催化剂所需载体的影响,并采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和N2吸附-脱附等手段对分子筛样品进行了表征。结果表明,制备温度为100~120℃,时间为4 h,尿素与TEOS物质的量之比为1和TEOS与ZSM-5物质的量之比为0.9~1.2时,得到的核壳结构分子筛呈现出优良的单分散性、完整性以及水热稳定性。最终在树枝状介孔SiO_2壳层负载高分散贵金属Pt,得到的双功能催化剂Pt/ZSM-5@MS在催化丙酮一锅法制备甲基异丁基酮(MIBK)反应中表现出较高的活性及良好的循环使用性能。     

壳聚糖/聚乙烯醇/壳寡糖抑菌纳米纤维膜的制备和性能研究

以壳聚糖(CS)为基材,使用静电纺丝的方法制备了搭载壳寡糖(CHOS)的CS/聚乙烯醇(PVA)/CHOS纳米纤维膜,并对纳米纤维膜的微观形貌、结构、抑菌性、亲水性以及溶解性能进行了研究.研究发现:CS/PVA/CHOS纳米纤维膜具备均匀密致的微观形貌;FT-IR测试表明,CHOS以物理混合的形式分散在CS/PVA/C...     

二氧化钛基核壳结构纳米材料制备进展

二氧化钛有着较高的光催化性能,因此在光电转换、光催化等领域上有着广泛的应用,但其催化效率却不是很高,近年来,越来越多的人研究以二氧化钛为基的核壳结构纳米材料。文章根据不同的制备方法,从表征方法、结构特征和催化活性等方面介绍了近年来一些以二氧化钛为基的核壳结构纳米材料的制备进展并展望了二氧化钛基核壳结构纳米材料的发展前景。     

Dual Drug Release Electrospun Core-Shell Nanofibers with Tunable Dose in the Second Phase

This study reports a new type of drug-loaded core-shell nanofibers capable of providing dual controlled release with tunable dose in the second phase. The core-shell nanofibers were fabricated through a modified coaxial electrospinning using a Teflon-coated concentric spinneret. Poly(vinyl pyrrolidone) and ethyl cellulose were used as the shell and core polymer matrices respectively, and the content of active ingredient acetaminophen (APAP) in the core was programmed. The Teflon-coated concentric spinneret may facilitate the efficacious and stable preparation of core-shell nanofibers through the modified coaxial electrospinning, where the core fluids were electrospinnable and the shell fluid had no electrospinnability. The resultant nanofibers had linear morphologies and clear core-shell structures, as observed by the scanning and transmission electron microscopic images. APAP was amorphously distributed in the shell and core polymer matrices due to the favorite second-order interactions, as indicated by the X-ray diffraction and FTIR spectroscopic tests. The results from the in vitro dissolution tests demonstrated that the core-shell nanofibers were able to furnish the desired dual drug controlled-release profiles with a tunable drug release amount in the second phase. The modified coaxial electrospinning is a useful tool to generate nanostructures with a tailored components and compositions in their different parts, and thus to realize the desired functional performances.     

海藻酸钠/脲醛树脂复合微胶囊的缓释动力学特性

采用两步法制备海藻酸钠/脲醛树脂复合微胶囊。在树脂化阶段引入海藻酸钠(SA)参与脲醛树脂(UF)的缩聚反应形成复合壳层,制备了阿维菌素复合微胶囊。通过FTIR、TG、SEM、粒度分析等表征微胶囊的结构特征、组成成分、表观形貌、粒度分布。结果表明,SA的引入可有效改善脲醛树脂微胶囊的团聚现象,提高药物的包覆率至60%以上。释放性能研究显示,复合微胶囊的缓释能力较脲醛树脂微胶囊提高,72 d累计释放率由27.5%增至44.5%,且释放速率受pH、温度的影响,25℃下酸性介质中27d累计释放率超过50%。释放行为均可用Korsmeyer-Pappas动力学模型进行描述。     

核壳型多孔富硒缓释性肥料研究及制备

采用废旧玻璃、富硒矿粉和高岭土掺杂一定量的硼酸在最高温度860℃条件下制备核壳结构富硒缓释性玻璃肥料。本研究创新性地利用核壳结构来制备富硒肥,并掺杂一定量的硼酸来改善富硒玻璃肥料的缓释性的能力。通过EDS,XRD和SEM对制备完成的核壳结构富硒缓释性玻璃肥料元素组成和表面形貌进行表征,并通过原子荧光光度计测试制备的玻璃肥缓释性及硒析出效果。结果表明,在最佳优化比配方和最佳工艺条件下可使玻璃肥缓释性达到实验设计要求,核壳结构富硒缓释性肥料的缓释时间大于90天,在1 L水中1 kg缓释性肥料对硒元素释放量维持在0.13 mg,核壳结构中壳内的气孔大小适中,分布均匀,缓释效果优良。     

Exploring the backbone dynamics of native spider silk proteins in Black Widow silk glands with solution-state NMR spectroscopy

Spider dragline silk is an outstanding biopolymer with a strength that exceeds steel by weight and a toughness greater than high-performance fibers like Kevlar. For this reason, understanding how a spider converts the gel-like, aqueous protein spinning dope within the major ampullate (MA) gland into a super fiber is of great importance for developing future biomaterials based on spider silk. In this work, the initial state of the silk proteins within Black Widow MA glands was probed with solution-state NMR spectroscopy. ¹⁵N relaxation parameters, T₁, T₂ and ¹⁵N-{¹H} steady-state NOE were measured for twelve backbone environments at two spectrometer frequencies, 500 and 800 MHz. The NMR relaxation parameters extracted for all twelve environments are consistent with MA silk protein backbone dynamics on the fast sub-nanosecond timescale. Therefore, it is concluded that the repetitive core of spider MA proteins are in an unfolded, highly flexible state in the MA gland.     

Production of silk sericin/silk fibroin blend nanofibers

Silk sericin (SS)/silk fibroin (SF) blend nanofibers have been produced by electrospinning in a binary SS/SF trifluoroacetic acid (TFA) solution system, which was prepared by mixing 20 wt.% SS TFA solution and 10 wt.% SF TFA solution to give different compositions. The diameters of the SS/SF nanofibers ranged from 33 to 837 nm, and they showed a round cross section. The surface of the SS/SF nanofibers was smooth, and the fibers possessed a bead-free structure. The average diameters of the SS/SF (75/25, 50/50, and 25/75) blend nanofibers were much thicker than that of SS and SF nanofibers. The SS/SF (100/0, 75/25, and 50/50) blend nanofibers were easily dissolved in water, while the SS/SF (25/75 and 0/100) blend nanofibers could not be completely dissolved in water. The SS/SF blend nanofibers could not be completely dissolved in methanol. The SS/SF blend nanofibers were characterized by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry, and differential thermal analysis. FTIR showed that the SS/SF blend nanofibers possessed a random coil conformation and ß-sheet structure.     

载药聚乳酸纤维膜的制备及释药性能研究

将药物——消炎痛和聚乳酸(PLA)同时溶解在三氯甲烷∶丙酮(体积比2∶1)的混合溶液中,制得均匀的纺丝液,通过静电纺丝制备载药PLA纤维膜。通过扫描电镜(SEM)观察其形貌结构;通过紫外分光光度计检测其释放在磷酸缓冲溶液(PBS)中药物的吸光度,并计算其释药速率。结果表明:纤维的平均直径随着含药量的增加而减小,随着PLA质量分数的增加而增加;释药速率随着纤维直径的减小而加快;与纯药粉的释药速率相比,载药PLA纤维膜有明显的缓释性,提高了药物的利用率及安全性。