乳液静电纺丝PLA/PEG微纳纤维膜的可控制备及负载亲疏水性药物的释放

采用低能相反转法,以聚乳酸(PLA)、疏水性药物喜树碱(CPT)溶液为油(O)相,以明胶水溶液、亲水性药物黄芪多糖(APS)为水(W)相,制备水包油(O/W)初乳液.通过控制聚乙二醇(PEG)的浓度和分子量制备O/W纺丝液,经乳液静电纺丝获得PLA/PEG微纳纤维膜.采用粒径分布、光学显微镜(OM)、扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)、接触角测试和细胞毒性实验对初乳液和PLA/PEG微纳纤维膜进行表征,并通过激光共聚焦显微镜(CLSM)观察药物的分布情况.结果表明,通过乳液静电纺丝可成功制备亲水性良好的不同微纳结构的PLA/PEG微纳纤维膜.PLA/PEG微纳纤维膜形貌不同,亲水性存在差异,无细胞毒性.体外药物释放结果表明,与pH=6.8和7.4的释放介质相比,在pH=5.8的释放介质中,药物累积释放率较高,表明载药PLA/PEG微纳纤维膜能够有效减缓CPT的释放,而APS释放速率较快,可实现亲疏水性药物的差别性释放.     

离子液体中纤维素/纳米层状ZnO复合抗菌纤维的制备及性能

以表面活性剂十二烷基磺酸钠(SDS)为模板,Zn(NO_3)_2·6H_2O和NaOH为锌源和沉淀剂,通过改进的模板法在温和条件下制得纳米层状ZnO.以离子液体1-烯丙基-3-甲基咪唑氯盐([Amim]Cl)为溶剂,木浆纤维素和纳米层状ZnO为原料,采用溶液共混方法,通过干湿法纺丝制备了ZnO质量分数分别为3%,5%,7%及9%的纤维素/ZnO纳米复合纤维.采用X射线衍射(XRD)、X射线光电子能谱(XPS)、透射电子显微镜(TEM)、场发射扫描电子显微镜(SEM)及热重分析(TG)等方法对纳米层状ZnO及纤维素/ZnO复合纤维进行了表征,并探讨了ZnO的加入对复合体系流变性的影响,同时对复合纤维进行了力学和抗菌性能测试.研究结果表明,所制备氧化锌纯度高,且呈现出重复周期为3.58 nm的层状结构,抗菌性能优异.纳米层状ZnO的加入提高了纤维素纤维的热稳定性和机械强度,同时赋予纤维对金黄色葡萄球菌和大肠杆菌的抑菌性.ZnO片层被纤维素链剥离,并均匀分散于纤维素/ZnO复合物中.ZnO的加入增大了纤维素溶液的黏度,当ZnO含量达到5%以上时,在整个频率范围内,弹性模量大于损耗模量,纳米粒子可稳定悬浮.     

多次交替浸渍法构筑簇状ZnO的PAN复合纳米纤维膜及其光催化性能

以聚丙烯腈(PAN)与氯化锌(ZnCl2)作为前驱物,采用静电纺丝工艺制备PAN/ZnCl_2复合纳米纤维膜,分别采用多次冷热交替浸渍法和单次冷热静置浸渍法得到簇状PAN/ZnO-1和PAN/ZnO-2复合纳米纤维膜。利用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、X射线能量色散光谱(XPS)和热重分析仪(TG)对复合纳米纤维膜的表面形貌和微结构进行了表征,并以亚甲基蓝(MB)为污染物模型,评价其光催化降解性能。结果表明:经冷热交替浸渍后,纳米ZnO粒子均匀地附着在PAN纤维表面,尤其在PAN/ZnO-1复合纳米纤维膜表面还出现了花状ZnO粒子;相比单次冷热静置浸渍法处理的PAN/ZnO-2复合纳米纤维膜,经多次冷热交替浸渍的PAN/ZnO-1复合纳米纤维膜循环使用3次后对MB的降解率仍可达到90%以上,具有更好的光催化活性和循环使用性能。同时,MB溶液的初始质量浓度、催化剂用量和染料溶液的pH等因素对样品的的光催化降解率有一定影响。     

阿司匹林/淀粉/聚乙烯醇纳米纤维膜的制备及其缓控释性能研究

采用静电纺丝技术制备了阿司匹林(AS)/玉米淀粉(ST)/聚乙烯醇(PVA)复合纳米纤维膜.利用扫描电镜观察到纳米纤维成连续三维立体网状结构;红外光谱分析表明,AS,PVA和ST三者之间能够通过氢键相互作用;X-射线衍射分析结果表明,药物基本被包裹于纤维之中,但AS的含量对纤维表面形态有一定影响;体外溶出实验结果表明,通过调整AS的载入量及压片压力,可以调控药物的缓释时间;同时,改变PVA与ST比例,可以调控药物的释放速率.     

丁香酚/改性聚乙烯醇抗菌复合膜的制备与性能

活性包装可通过释放功能性物质而提高食品的防腐保鲜性能，以延长食品的货架期。聚乙烯醇(PVA)由于其优异的综合性能在包装领域备受关注，但其强亲水性使其存在耐水性差、机械性能弱等问题。据此，本研究选用纤维素纳米纤维(CNF)复合PVA，进而通过柠檬酸(CA)交联，制备PVA-CC成膜基材；再将天然植物精油丁香酚(EUG)作为抗菌模板分子载入到PVA-CC聚合物网络中，制备了具有抗菌活性的复合膜PVA-CCE。通过对复合膜的结构和性能进行一系列的表征与测试发现，该复合膜具有良好的机械性能、耐水性、热稳定性和抗菌性。经过CA交联后的复合膜PVA-CCE在水中的溶胀率可从原来的495.74%降低至72.00%，耐水性得到了显著提升；并且与纯的PVA膜相比，该复合膜的熔融温度降低了11℃，分解温度提高了20℃，这说明经过CA共价交联后PVA的加工性能得到改善。同时，复合膜中存在游离的CA能够降低分子间的作用力而起到增塑作用，并可以与EUG协同抗菌增强复合膜的抗菌效果。这些实验结果表明，复合膜PVA-CCE在活性包装领域具有十分广泛的应用前景。     

纳米纤维素/聚乳酸全绿色纳米复合材料的制备及性能

制备得到纳米纤维素(NC),其为横向尺寸20~40 nm、长度400~2000 nm的纳米丝.对NC进行醋酸酯化疏水改性得到醋酸酯化纳米纤维素(ANC).分别将NC和ANC与聚乳酸(PLA)复合制备纳米复合材料,研究了NC添加量、疏水改性及与PLA的复合方式对PLA力学性能和结晶性能的影响规律.结果表明,采用溶液浇铸法制备纳米复合膜时,ANC在PLA基体中的分散性优于NC,但是对于复合膜拉伸性能的改善不明显.DSC等温结晶结果表明,ANC可以提高PLA的结晶度和结晶速率;采用熔融复合法制备的NC/PLA纳米复合材料,不仅保持了PLA的高强度、高模量和较高的热稳定性,而且显著改善了其韧性,当NC添加量为3.5%(质量分数)时,断裂伸长率比纯PLA提高了12.1倍.     

基于静电纺丝技术的PET/PVA复合超滤膜制备条件的探索

采用多喷头静电纺丝技术制备了复合超滤膜,该复合超滤膜是以聚对苯二甲酸乙二酯(PET)无纺布为支撑层,PET/PVA复合纳米纤维膜为分离层,再用丙酮和水的混合溶剂处理得到致密分离层.采用扫描电镜法(SEM)、红外光谱法(FTIR)对复合膜表面进行表征,测试了复合超滤膜的抗水解性能.SEM结果表明,复合膜表面的PET纳米纤维的直径为960 nm,PVA纳米纤维的直径为320 nm,用不同比例的混合溶剂对复合超滤膜进行处理会产生不同的表面形貌,最佳的比例是w(丙酮)/w(水)=30/70.抗水解性能实验结果显示比较适宜的交联剂加入量为2 wt%,用该含量对复合膜进行交联,复合膜具有较好的抗水解性能,其中重量损失率为2.12%,溶胀度为3.62%.红外光谱分析表明,交联处理后,复合膜表面的—OH量大大减少,耐水性能提高,交联前后膜表面在—C O和C—O—C处的吸收峰有很大的区别.     

低压近场静电纺丝ZnO/PVDF复合微米纤维阵列的制备及压力传感性

利用低压近场静电纺丝技术制备了ZnO/PVDF(聚二偏氟乙烯)微米纤维平行阵列, 通过光学显微镜、扫描电子显微镜(SEM)和X射线能量色散光谱(EDS)对ZnO/PVDF微米纤维进行了表征. 该复合纤维的平均直径约为40 μm. EDS分析测试证明ZnO纳米颗粒已经掺杂进入了平行微米纤维中. 压电性能和电学性能测试结果表明, ZnO/PVDF微米纤维阵列的压电性能增强. 研究结果表明, 近场电纺丝ZnO/PVDF复合微米纤维阵列在压电型压力传感器和纳米发电机领域具有潜在的应用价值.     

聚乳酸/氧化锌柱撑皂石纳米复合材料制备与性能及结构表征

通过微波水解法制备了ZnO柱撑皂石,并以其为加工助剂制备了聚乳酸(PLA)/ZnO柱撑皂石纳米复合材料.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、对ZnO柱撑皂石及PLA/ZnO柱撑皂石纳米复合材料的结构进行了表征,并对其力学性能和热稳定性能进行了测试.微观结构分析表明,ZnO柱撑皂石呈现剥离状,并均匀分散在PLA基质中.力学性能研究表明0.3%ZnO柱撑皂石的加入有助于改善PLA复合材料的断裂伸长率.SEM分析表明PLA复合材料的断面发生明显改变,表现良好韧性;DSC结果显示纳米ZnO柱撑皂石可以降低复合材料的玻璃化转变温度、结晶温度,有助于提高PLA复合材料的结晶度,与XRD分析相吻合;热重分析表明ZnO柱撑皂石可以提高PLA复合材料的热稳定性.测试结果表明,ZnO柱撑皂石在PLA基质中起到了异相成核的作用,促进了PLA基质的结晶.     

静电纺丝复合反渗透膜的改性制备与脱盐性能

利用静电纺丝技术在无纺布上制备PET纳米纤维膜, 并用交联壳聚糖对其进行改性得到壳聚糖改性纳米纤维复合膜. 以间苯二胺(MPD)和均苯三甲酰氯(TMC)为单体, 采用界面聚合法在壳聚糖改性纳米纤维复合膜的表面制备聚酰胺分离层, 得到新型静电纺丝纳米纤维基复合反渗透膜. 新型复合反渗透膜具有典型的聚酰胺复合反渗透膜的表面脊-谷结构. 从膜的表面形貌、 亲水性、 分离性能等3个方面对水相MPD溶液中阴离子表面活性剂十二烷基苯磺酸钠(SDBS)的含量对膜结构和性能的影响进行了系统研究. 结果表明, SDBS的含量对膜形态结构的均匀性和亲水性有一定影响, 且随着SDBS含量的增加, 膜的脱盐率先增大后减小, 而通量小幅度上升后, 先减小后增大, 呈现规律性变化.     

Controlled release of antibiotics from poly‐ε‐caprolactone/polyethylene glycol wound dressing fabricated by direct‐writing melt electrospinning

Wound dressing, which can release anti‐infectives in a controlled way, is taking an important role in the treatment and recovery of the open wound. An adequate release of antibiotics can prevent infections from microorganisms effectively. Among the new candidates of fabricating base materials for wound dressing, electrospinning fiber mats are attracting numerous attentions for their excellent performance in controlled drug delivery. The drug release behavior of electrospinning fiber mats can be tuned by changing the chemical components and the geometric structures of the mats. In this study, fiber mats with different geometric structures, which composed of poly‐ε‐caprolactone (PCL), polyethylene glycol (PEG), and ciprofloxacin (Cip) with different blending ratios, were successfully fabricated by direct‐writing melt electrospinning, and the release behavior of Cip were subsequently investigated in vitro. The results showed that the addition of PEG improved the hydrophilicity of the mats, which in turn affected the manner of drug release. The presence of PEG changed the releasing mechanism from a non‐Fickian diffusion into Fickian diffusion, which indicated that the diffusion of Cip from the composite fiber mats became the main factor of drug release instead of polymer degradation. Besides, with the same composition but different geometric structures, the drug release behavior is of significant difference. Therefore, all the Cip‐loaded composite fiber mats showed antibacterial activities but with different efficiency. In summary, the release of the drug could be controlled by adding PEG and changing the geometric structures according to the different requirement of wound dressings.     

Synthesis,Morphological Structures,and Material Characterization of Electrospun PLA:PCL/Magnetic Nanoparticle Composites for Drug Delivery

The effects of pure and impure magnetic nanoparticles (MPs) with three different concentrations (0.01, 0.1, and 1 wt %/v) on the morphological structure, crystallinity level, thermal properties and constituent interactions of electrospun poly(lactic acid) (PLA): poly(ε‐caprolactone) (PCL)‐based composites were investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and drug release tests using UV–vis spectrophotometry. Tetracycline hydrochloride (TCH), as a typical therapeutic compound, was loaded into these composite fibrous structures to study their application for drug delivery. The infrared spectra of composite nanofibers confirm the successful embedding of MPs into the fibrous networks. The addition of pure MPs increased the solution viscosity and thus promoted the MP dispersion inside the electrospun composite fiber mats. Impure MPs led to considerably lower average fiber diameters, and could generate unique cell structures that were reported for the first time in this study. The accelerated release of TCH was found by adding pure MPs to PLA:PCL blends. This characteristic was reflected in the parameters of Ritger‐Peppas and Zeng models, which were well fitted to our experimental drug release data. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1607–1617     

Synthesis,characterization, and hydrolytic degradation of polylactide/poly(ϵ-caprolactone)/nano-silica composites

Poly(lactic acid) (PLA)/poly(?-caprolactone) (PCL)/nano-silica composite degradable films were prepared by a solvent casting method. SEM results showed that the nano-silica particles were dispersed uniformly in the PLA/PCL matrix. TGA results indicated that the thermal decomposition temperature rose with the increase of nano-silica content. The tensile strength of the composites was enhanced with the increase of nano-silica content up to 2%. The tensile strength increased with the silica content and reached its maximum (22.51 Mpa). The improvement in the water uptake ratio in the PLA/PCL/silica nanocomposites may be attributable to the presence of silica nanoparticles in the PLA/PCL matrix. After 15 weeks total processing time for the solution of alkaline and phosphate buffer, the performances of 16.23% and 3.65% for degradation.     

Construction of crosslinking network structures by adding ZnO and ADR in intumescent flame retardant PLA composites

Different proportion of nano zinc oxide (nano ZnO) and chain extender (ADR) were combined with the intumescent flame retardant and then added into the PLA matrix. The thermal stability, flame retardant performance, and mechanical properties were studied. The gel content results showed that crosslinking structures were obtained after the addition of nano ZnO and ADR, which were generated by the catalytic chain scission effect of nano ZnO and chain extension effect of ADR. With addition of 1% nano ZnO and 1.6% ADR, the gel content of flame retardant PLA composite reached the highest value (14.2%). Meanwhile, the corresponding flame retardant PLA composite with 1% nano ZnO and 1.6% ADR, named FRPLA/ZnO/ADR-1, exhibited an overall improved properties including the flame retardant properties and mechanical performance, which passed the UL94 V-0 level with a limiting oxygen index value of 40.1%. Compared to FRPLA (flame retardant PLA without ZnO and ADR), the peak heat release rate and the total smoke production of FRPLA/ZnO/ADR-1were reduced by 60% and 67% respectively, and the final mass improved from 12% to 38%. In addition, the tensile strength and elongation at break of FRPLA/ZnO/ADR-1 increased by 25%, 14% compared with that of FRPLA. The impact strength was 15.1 kJ/m², which is similar to the pure PLA (15.6 kJ/m²). It indicated that the addition of nano ZnO and ADR could balance the flame retardant performance and the mechanical properties of the flame retardant PLA.     

磷钼酸/聚苯乙烯/聚乙烯醇电纺纤维膜的制备及性能

采用静电纺丝法制备了磷钼酸/聚苯乙烯(PS)/聚乙烯醇(PVA)复合纤维,并将其模压成膜.利用红外光谱(IR)、扫描电子显微镜(SEM)及X射线能谱(EDX)等对复合纤维及其膜的结构与形貌进行表征,并对复合纤维膜的光催化性能、力学性能及在水中稳定性进行测试.结果表明,在复合纤维中磷钼酸的Keggin结构得到保持.PS与PVA质量比为1∶1时,复合纤维形貌最佳,表面光滑,直径较小且分布均匀,复合纤维的直径随着磷钼酸含量的增加而减小.将磷钼酸固载于复合纤维膜上比直接使用具有更高的光催化活性,光照25 min后接近98%的甲基橙降解;复合纤维膜易于回收再利用,5次重复使用后,复合纤维膜没有破损,磷钼酸损失较少,光催化性能无明显下降.复合纤维膜的强度随磷钼酸含量的增加先增大后减小,韧性随PVA含量的增加而增大,随磷钼酸含量的增加而减小.     

Preparation and Characterization of Aligned PLLA/PCL/HA Composite Fibrous Membranes

Aligned poly(L-lactide) (PLLA)/poly(?-caprolactone) (PCL)/hydroxyapaite (HA) composite fibrous membranes were fabricated by electrospinning. Their morphology, thermal stability, mechanical properties, hydrophilic properties and biocompatibility were investigated. The electrospun fibers are highly aligned and the HA are oriented along the fiber axis. When HA are incorporated, the PLLA/PCL/HA composite fibers become thinner due to the increased conductivity. In addition, the aligned HA reinforce the electrospun fibrous membranes. The larger porosity and higher hydrophilic properties induced by HA in the electrospun fibers have improved the degradation of the PLLA/PCL/HA fibrous membranes which have no toxic effect on proliferation of adipose-derived stem cells.     

基于多巴胺自聚合与表面接枝PHGH制备抗菌纳滤膜

在水溶液中将聚六亚甲基单胍盐酸盐(PHGH)共价接枝在经多巴胺自聚合改性的聚砜膜表面, 制备具有抗菌性能的纳滤膜. 采用全反射红外光谱(ATR-FTIR)、 扫描电子显微镜(SEM)和接触角测试考察膜表面的结构、 形貌和亲水性变化. 探讨PHGH含量对膜的接枝度及分离性能的影响, 并对膜的抗菌性能进行了评价. 结果表明, 经过多巴胺的自聚合和表面接枝PHGH后, 聚砜膜表面形成了具有纳滤分离性能的活性层, 并且膜表面亲水性得到改善. 随着PHGH含量的增大, 膜的纯水通量降低, 而对无机盐和染料的截留性能提高. 接枝后的复合膜具有较高的抗菌性能, 当PHGH含量为3%(质量分数)时, 抗菌率可达98.5%.     

聚ε-己内酯/聚吡咯电纺膜的制备与性能

以吡咯(Py)和聚ε-己内酯(PCL)为原料、氯仿为溶剂,并掺杂一定量的十二烷基硫酸钠制备电纺膜,利用三氯化铁的氧化作用原位生成聚吡咯(PPy).对所得到的PCL/PPy电纺膜用红外光谱进行表征,在扫描电镜和透射电镜下观察纤维形貌,并测定力学性能和体积电阻率.结果表明,所生成的PPy以纳米粒子形式附着在电纺纤维表面,随着Py相对于PCL的质量百分含量由0增加到20%,PCL/PPy电纺膜的纤维直径从(730±341)nm逐渐下降至(325±84)nm;膜的拉伸模量和拉伸强度由不含Py的(25.7±0.8)MPa和(2.48±0.14)MPa分别增加至含有20%Py的(48.4±7.6)MPa和(5.05±0.59)MPa,断裂伸长率由(129±27)%下降至(86.2±9.1)%;体积电阻率降低了2～3个数量级.该PCL/PPy电纺纤维膜以期可作为电活性材料用于功能或生物医用领域.     

In vitro bioactivity of titanium implants coated with bicomponent hybrid biodegradable polymers

In order to improve the bioactivity and biocompatibility of titanium (Ti) implants, we designed a novel biodegradable hybrid (polycaprolactone/polylactic acid, PCL/PLA) membrane to coat Ti surfaces. The bicomponent PCL/PLA membrane was applied to a Ti substrate starting with the coating of Ti samples with a porous PLA film layer using a dip-coating technique. This was followed by deposition of electrospun PCL nanofibers onto the Ti substrate, resulting in a PCL/PLA bicomponent hybrid coating layer. The cytocompatibility, bioactivity and corrosion performance of PCL/PLA-coated Ti samples was compared to PLA-coated Ti samples and untreated Ti samples. When placed in Hanks’ solution, apatite formed on the treated Ti samples but not on untreated Ti samples. When assessing Ti cytocompatibility and MC3T3-E1 osteoblast adherence, proliferation, and survival, our results showed superior performance by polymer-treated Ti samples compared to untreated Ti samples, and maximal osteoblast cell viability was achieved with the bicomponent PCL/PLA hybrid coating layer. Furthermore, during the potentiodynamic polarization test in simulated body fluid, the polymer-coated Ti samples showed corrosion resistance. Therefore, the approach described herein may serve as a basis for the development of polymer-coated Ti surfaces that can be used in dental or orthopedic implants.     

聚乳酸-乙醇酸/纳米氧化锌复合电纺纤维装载亲疏水药物的控释及体外细胞毒性

利用静电纺丝技术制备了负载亲水性药物阿霉素(DOX)以及疏水性药物喜树碱(CPT)的复合纳米纤维. 先用巯基封端的普朗尼克(F127)修饰纳米氧化锌(FZnO), 再将FZnO负载盐酸阿霉素(DOX@FZnO), 最后将DOX@FZnO与CPT一起纺入聚乳酸-乙醇酸(PLGA)纤维中. 体外药物释放结果表明, 复合纳米纤维能够减小亲水性药物的突释, 减缓药物释放速率, 延长药物释放时间. 体外细胞活性结果表明, 双载药复合纤维比单载药复合纤维具有更强的细胞毒性, 能够有效抑制癌细胞生长.