利用静电纺丝技术制备纳米黏土/聚乳酸复合纳米纤维与其表征

利用静电纺丝技术制备了纳米黏土/聚乳酸(PLA)复合纳米纤维,并将该复合纳米纤维收集成无纺布薄膜,采用SEM和TEM观察了复合纳米纤维的微观形貌和结构,分别利用XRD和TGA测试了复合纳米纤维的结晶行为及热学行为,并分析了复合纳米纤维薄膜的拉伸力学性能随纳米黏土含量的变化关系。结果表明:当PLA含量为10wt%、纳米黏土含量为1wt%、CHCl3与DMF体积比为3∶1溶剂条件下,所制备的纳米黏土/PLA复合纳米纤维的细度和均匀性均得到改善;XRD测试结果表明,纳米黏土成功附着在PLA中。TGA和力学测试结果表明,纳米黏土/PLA复合纳米纤维的热稳定性和力学性能相对于纯PLA纤维有较大幅度提高,当纳米黏土含量为1wt%时,其初始分解温度提高了60℃,拉伸强度、断裂伸长率和弹性模量分别提高了111.3%、74.9%和20.0%。     

预处理剂对陶瓷膜表面性质及渗透通量的影响

考察了不同预处理剂对陶瓷膜表面性质及渗透通量的影响,结果表明:表面活性剂的加入,使陶瓷膜表面的负电性以及亲水性得到提高,膜渗透通量从100L/(m2·h)提高到200L/(m2·h);碱式氯化铝中Al3+在膜表面的吸附,导致膜表面呈现正电位,相应的膜渗透通量只有50L/(m2·h);吸附剂对渗透通量的影响主要体现其在乳化废水中表面电位的不同,呈负电性的二氧化硅有利于渗透通量的提高,而呈正电性的氧化铝会导致膜通量的下降.     

膜结晶技术研究进展及应用前景

对一种新的分离技术——膜结晶进行了综述．介绍了膜结晶技术的产生、原理和优点，以及膜结晶的过程及膜结晶器的类型．概述了膜结晶在国内外的发展和应用状况，重点介绍了膜结晶在盐溶液结晶和生物高分子溶液结晶两个方面的研究与应用，并对膜结晶技术的前景作了展望．     

Effect of nerodilol and carvone on in vitro permeation of nicorandil across rat epidermal membrane

The objective of the study was to investigate the effect of nerodilol and carvone on the in vitro transdermal delivery of nicorandil so as to fabricate a membrane-moderated transdermal therapeutic system. The in vitro permeation studies were carried across the rat epidermal membrane from the hydroxypropyl methylcellulose (HPMC) gels (prepared with 70:30 v/v ethanol-water) containing selected concentrations of a terpene such as nerodilol (0% w/w, 4% w/w, 8% w/w, 10% w/w, or 12% w/w) or carvone (0% w/w, 4% w/w, 8% w/w, 12% w/w, or 16% w/w). The amount of nicorandil permeated (Q₂₄) from HPMC gel drug reservoir without a terpene was 3424.6 ± 51.4 μg/cm², and the corresponding flux of the drug was 145.5 ± 2.2 μg/cm²· h. The flux of nicorandil increased with an increase in terpene concentration in HPMC gel. It was increased ranging from 254.9 ± 3.1 to 375.7 ± 3.2 μg/cm²·h or 207.6 ± 4.7 to 356.7 ± 15.3 μg/cm²· h from HPMC gels containing nerodilol (4% w/w to 12% w/w) or carvone (4% w/w to 16% w/w), respectively. Nerodilol increased the flux of nicorandil by about 2.62-folds whereas carvone increased the flux of the drug by about 2.49-folds across the rat epidermal membrane. The results of the Fourier Transform Infrared (FT-IR) study indicated that the enhanced in vitro transdermal delivery of nicorandil might be due to the partial extraction of stratum corneum lipids by nerodilol or carvone. It was concluded that the terpenes, nerodilol and carvone, produced a marked penetration enhancing effect on the transdermal delivery of nicorandil that could be used in the fabrication of membrane-moderated transdermal therapeutic systems.     

GKSS渗透汽化和蒸气渗透技术

介绍了德国GKSS研究中心高性能渗透汽化膜的开发、膜组件及系统设计．分析了GKSS渗透汽化和蒸气渗透技术的工业应用现状．     

熔体微分电纺PLA/OMMT可降解纳米纤维膜制备及污染处理

采用无溶剂的熔体静电纺丝技术制备可降解聚乳酸(PLA)纳米纤维,是一种很有前景和挑战性的绿色制备技术。其制备的纳米纤维膜孔隙率高、吸附能力强,可高效地处理环境污染问题。借助自制的熔体微分电纺装置,在PLA中引入了有机改性蒙脱土(OMMT),在260℃下制备了PLA/OMMT纳米纤维膜。探究了OMMT含量对PLA纤维形貌、吸油性能、空气过滤性能及降解性能的影响,并获得了最佳的OMMT配比含量。研究表明:加入OMMT后PLA热稳定性提高,结晶度大幅降低。OMMT质量分数为2%时制备的纤维,其直径为450nm。该纤维膜吸油倍率为133.5g/g,是市售PP无纺布的4~5倍,保油倍率为84.2g/g,具有良好的重复使用性能。针对粒径≥0.3μm尘埃粒子的空气过滤效率为99.31%,达到欧标H11过滤等级。且相比于纯PLA纤维膜降解性能提高,减少了二次污染,符合工业化绿色环保要求。     

质子传导膜制备方法放大与膜性能表征

为了满足新能源电池对质子选择性导电膜的需要,提出一种质子传导膜的新型制备工艺,并进行质子传导膜的制备工艺放大.以聚偏氟乙烯(PVDF)和烯丙基磺酸钠(SAS)为原料,成功制备长1 000mm、宽800mm的质子传导膜.膜性能测试结果显示,质子传导膜电导率随SAS质量分数变化显著.当SAS质量分数为20%时,膜电导率3.0×10-2 S/cm;膜化学稳定性良好,使用Fenton试剂氧化法测得膜剩余质量分数97.5%;屈服强度23N/mm2,膜爆破强度为2MPa;TGA分析膜分解温度高于400℃.该膜应用于全钒液流电池,自放电实验测得开路电压下降速率为1.41×10-3 V/h,库伦效率93%.结果表明,膜材料综合性能良好,有望在全钒液流电池产业化过程中得到大规模应用.     

电纺制备聚丙烯腈/聚偏氟乙烯复合纤维膜及其空气过滤性能

以聚偏氟乙烯(PVDF)为芯层,聚丙烯腈(PAN)为皮层,通过同轴法静电纺丝技术制备PAN/PVDF纳米复合纤维膜。通过向纤维膜的皮层中加入纳米硅粉、气相白炭黑、硅溶胶三种不同的纳米粒子和改变皮芯层溶液挤出速度对PAN/PVDF纳米纤维膜进行结构优化。同时,采用BET、SEM、水接触角、纤维强度仪等对纤维膜的孔结构参数、表面形貌、亲水性、力学性能等进行研究。结果表明:在皮层中加入硅溶胶后的溶液导电能力达到32.90 μL/cm,PAN/PVDF纤维膜力学性能最好,纵向断裂强度达到13.02 MPa。含有硅溶胶的口罩布的品质因子达到0.0236,远大于纯聚丙烯(PP)无纺布的品质因子(0.0127),过滤性显著提高。      

静电纺丝制备纳米海藻酸钠/魔芋葡甘聚糖-菊糖纤维膜

采用静电纺丝技术制备纳米海藻酸钠/魔芋葡甘聚糖-菊糖（SA/KGM-INU）纤维膜。采用流变仪分析研究了加入不同量SA对SA/KGM-INU溶胶流变特性的影响,利用SEM、DSC、FTIR和TGA研究了不同量SA对纳米SA/KGM-INU纤维膜结构和性能的影响。结果表明,纳米SA/KGM-INU复合纤维膜表面粗糙程度随SA含量增加而减小,黏度随SA含量的增加而增大,热稳定性随SA含量的增加而增强。纳米SA/KGM-INU纤维膜的制备,旨在为其它天然高分子基复合材料的研究开发提供一定的实验数据及理论基础。     

渗透汽化和蒸汽渗透技术的研究、应用现状及发展

综述了渗透蒸发技术和蒸汽渗透技术的研究和应用现状，并介绍了清华大学化工系的渗透汽化产业化开发工作．     

Improved oral bioavailability of fexofenadine hydrochloride using lipid surfactants: ex vivo,in situ and in vivo studies

The aim of the present study was to improve the dissolution, permeability and therefore oral bioavailability of the fexofenadine hydrochloride (FEX), by preparing lipid surfactant based dispersions using self-emulsifying carriers, i.e. Gelucire 44/14 (GLC) and d-α-tocopheryl polyethylene glycol 1000 succinate (Vitamin E TPGS or TPGS). The reprecipitation studies were conducted using these carriers to evaluate inhibition of reprecipitation by maintaining super saturation state. The aqueous solubility of the FEX was increased linearly with increasing GLC, TPGS concentrations as verified by the phase solubility studies. The dispersions of FEX were prepared in different drug/GLC (GD) and drug/TPGS (TD) ratios by melt method and evaluated. The prepared dispersions showed improved dissolution rate in distilled water as dissolution media and highest dissolution rate was achieved with dispersions prepared using TPGS. The solid state characterization was carried by differential scanning calorimetry and scanning electron microscopy indicated reduced crystallinity of the drug. Fourier transform infrared spectroscopy revealed the compatibility of drug with carriers. The ex vivo permeation studies conducted using intestinal gut sac technique, resulted in reduced efflux of the drug by inhibiting intestinal P-glycoprotein from the dispersions. The in situ perfusion studies and in vivo pharmacokinetic studies in male wistar rats showed improved absorption and oral bioavailability from the prepared dispersions as compared to pure drug.     

Development and in vitro/in vivo evaluation of dihydroergotamine mesylate loaded maltodextrin-pullulan sublingual films

Dihydroergotamine mesylate (DHE), ergotamine derivative, has been offered for clinical use to stop or treat symptoms of an emerging migraine as injection for more than a half century. It is shown that bioavailability of DHE greatly changes between the subjects and up to 99% of the orally absorbed dose may be cleared by first pass metabolism. The aim of this study was to design and optimize DHE fast-dissolving sublingual films for migraine treatment. For this purpose pullulan and maltodextrin was chosen as film-forming polymers and propylene glycol as plasticizer. For optimization process Box Behnken design was used. The formed films were free from air bubbles, cuttings, or cracks. Disintegration, mechanical strength and dissolution of films were compared. It is found that pullulan and maltodextrin formed films with the most desired properties at the concentration of 1.5% and 2%. The application of optimum formulation to rabbits showed that bioavailability of formulation is about 23.35% with a t_max 20?min. Due to this fast onset of action and higher bioavailability than oral administration, it is suggested that the polymer combinations of pullulan and maltodextrin formed successful films and were considered as an alternative dosage form for DHE in migraine therapy.     

静电纺丝运动轨迹的建模与仿真研究

静电纺丝作为一种简单而有效的方法,广泛应用于纳米纤维的制备.本文以静电纺丝过程中带电溶液为对象,将带电溶液模拟成多个离散化的带电粒子,对带电粒子进行受力分析,建立带电粒子的分子动力学模型.基于Runge-Kutta算法,对带电粒珠的运动轨迹进行了数值计算,并利用MATLAB软件进行了仿真.改变静电纺丝工艺参数,得到了带电粒珠的不同运动轨迹的仿真图像.在相同的工艺条件下进行了纺丝实验,实验所制备的纳米纤维轨迹与仿真图像相一致.分析结果表明,静电纺丝过程中,改变工艺参数可以实现纳米纤维的运动轨迹的可控.     

Novel small self-assembled resveratrol-bearing cubosomes and hexosomes: preparation,charachterization, and ex vivo permeation

Abstract

The study aims to elaborate novel self-assembled liquid crystalline nanoparticles (LCNPs) of resveratrol which has neuro-protective, anti-aging, and anticancer activity. Resveratrol loaded LCNPs fabrication and optimization for transdermal delivery was assessed via a quality by design approach based on 2³ full factorial designs. The cubic phase of LCNPs was successfully prepared using GMO (glyceryl monooleate) via the emulsification technique. Based on the factorial design, the independent operating variables significantly affected the five dependent responses. The cubosomes and hexosomes hydrodynamic diameters were in the nanometer range (135–256?nm) with narrow particle size distribution, high negative zeta potential ≥ ?27.9?mV, and entrapment efficiency ≥73.5%. The LCNPs succeeded in sustaining resveratrol release for almost 24?h, following a non-fickian transport of drug diffusion mechanism. Ex-vivo study revealed a significant enhancement up to six folds in the transdermal permeation of resveratrol-loaded LCNPs compared to its suspension. The selected LCNPs exhibited a high physical stability while retaining the cubic structure for at least 3 months. Quality by design approach successfully accomplished a predictable mathematical model permitting the development of novel LCNPs for sustained transdermal delivery of resveratrol.     

支撑液膜分离过程应用研究新进展

简要回顾液膜分离过程的发展史;介绍支撑液膜法的基本原理.在分析支撑液膜所存在问题的基础上重点论述近10年来支撑液膜的应用和发展.     

Influence of omega fatty acids on skin permeation of a coenzyme Q10 nanoemulsion cream formulation: characterization,in silico and ex vivo determination

Objective: The aim of this study was to develop a coenzyme Q10 nanoemulsion cream, characterize and to determine the influence of omega fatty acids on the delivery of coenzyme Q10 across model skin membrane via ex vivo and in silico techniques.

Methods: Coenzyme Q10 nanoemulsion creams were prepared using natural edible oils such as linseed, evening primrose, and olive oil. Their mechanical features and ability to deliver CoQ10 across rat skin were characterized. Computational docking analysis was performed for in silico evaluation of CoQ10 and omega fatty acid interactions.

Results: Linseed, evening primrose, and olive oils each produced nano-sized emulsion creams (343.93–409.86?nm) and exhibited excellent rheological features. The computerized docking studies showed favorable interactions between CoQ10 and omega fatty acids that could improve skin permeation. The three edible-oil nanoemulsion creams displayed higher ex vivo skin permeation and drug flux compared to the liquid-paraffin control cream. The linseed oil formulation displayed the highest skin permeation (3.97?±?0.91?mg/cm²) and drug flux (0.19?±?0.05?mg/cm²/h).

Conclusion: CoQ10 loaded-linseed oil nanoemulsion cream displayed the highest skin permeation. The highest permeation showed by linseed oil nanoemulsion cream may be due to the presence of omega-3, -6, and -9 fatty acids which might serve as permeation enhancers. This indicated that the edible oil nanoemulsion creams have potential as drug vehicles that enhance CoQ10 delivery across skin.     

Development and characterization of a mucoadhesive sublingual formulation for pain control: extemporaneous oxycodone films in personalized therapy

Objective: The aim of this work was the development of mucoadhesive sublingual films, prepared using a casting method, for the administration of oxycodone.

Materials and methods: A solvent casting method was employed to prepare the mucoadhesive films. A calibrated pipette was used to deposit single aliquots of different polymeric solutions on a polystyrene plate lid. Among the various tested polymers, hydroxypropylcellulose at low and medium molecular weight (HPC) and pectin at two different degrees of esterification (PC) were chosen for preparing solutions with good casting properties, capable of producing films suitable for mucosal application.

Results and discussion: The obtained films showed excellent drug content uniformity and stability and rapid drug release, which, at 8?min, ranged from 60% to 80%. All films presented satisfactory mucoadhesive and mechanical properties, also confirmed by a test on healthy volunteers, who did not experience irritation or mucosa damages. Pectin films based on pectin at lower degrees of esterification have been further evaluated to study the influence of two different amounts of drug on the physicochemical properties of the formulation. A slight reduction in elasticity has been observed in films containing a higher drug dose; nevertheless, the formulation maintained satisfactory flexibility and resistance to elongation.

Conclusions: HPC and PC sublingual films, obtained by a simple casting method, could be proposed to realize personalized hospital pharmacy preparations on a small scale.     

膜技术在有机蒸气回收中的工业应用

介绍了有机蒸气分离膜的分离原理，并分别介绍了有机蒸气分离膜在石油化工、聚氯乙烯行业中的应用．     

A novel approach via combination of electrospinning and FDM for tri-leaflet heart valve scaffold fabrication

In this paper, a novel combination method of electrospinning and rapid prototyping (RP) fused deposition modeling (FDM) is proposed for the fabrication of a tissue engineering heart valve (TEHV) scaffold. The scaffold preparation consisted of two steps: tri-leaflet scaffold fabrication and heart valve ring fabrication. With the purpose of mimicking the anisotropic mechanical properties of the natural heart valve leaflet, electrospun thermoplastic polyurethane (ES-TPU) was introduced as the tri-leaflet scaffold material. ES-TPU scaffolds can be fabricated to have a well-aligned fiber network, which is important for applications involving mechanically anisotropic soft tissues. We developed ES-TPU scaffolds as heart valve leaflet materials under variable speed conditions and measured fiber alignment by fast Fourier transform (FFT). By using FFT to assign relative alignment values to an electrospun matrix, it is possible to systematically evaluate how different processing variables affect the structure and material properties of a scaffold. TPU was suspended at certain concentrations and electrospun from 1,1,1,3,3,3-hexafluoro-2-propanol onto rotating mandrels (200―3000 rpm). The scaffold morphological property and mechanical anisotropic property are discussed in the paper as a function of fiber diameter and mandrel RPM. The induction of varying degrees of anisotropy imparted distinctive material properties to the electrospun scaffolds. A dynamic optimum design of the heart valve ring graft was constructed by FDM. Fabrication of a 3D heart valve ring was constructed using pro-engineer based on optimum hemodynamic analysis and was converted to an STL file format. The model was then created from PCL which was sewed and glued with electrospun nanofibrous leaflets. This proposed method was proven as a promising fabrication process in fabricating a specially designed graft with the correct physical and mechanical properties.     

A simple and sensitive method for determination of vitamins D3 and K1 in rat plasma: application for an in vivo pharmacokinetic study

Purpose: To develop and to validate a simple but sensitive method for determination of vitamins D₃ and K₁ in rat plasma.

Methods: The sample treatment included protein precipitation by cold acetonitrile, evaporation, reconstitution with methanol and filtration. The chromatography conditions included Xterra RP18 3.5?µm 4.6?×?100?mm column at ambient temperature and mobile phase consisting of methanol/water (93/7, v/v) at 0.5?mL/min flow rate. Vitamin D₃ and probucol were detected at 265?nm and vitamin K₁ at 239?nm. Rats were administered intravenously by 0.1?mg/kg of vitamin D₃ or K₁ and the blood samples were withdrawn pre-administration and at pre-determined time points post-administration. The pharmacokinetic analysis was performed using a non-compartmental approach.

Results: The calibration curves in rat plasma were linear up to 5000?ng/mL for both vitamins. The limit of quantification (LOQ) was 20?ng/mL for vitamin D₃ and 40?ng/mL for K₁. Inter- and intra-day precision and accuracy were below 15%. The pharmacokinetic parameters of vitamin D₃ following intravenous administration were: AUC_0?∞?=?11323?±?1081?h?×?ng/mL, V_d?=?218?±?80?mL/kg, CL?=?8.9?±?0.8?mL/h/kg, t_1/2?=?16.8?±?5?h; and of vitamin K₁: AUC_0?∞?=?2495?±?297?h?×?ng/mL, V_d?=?60?±24?mL/kg, CL?=?40.5?±?5.1?mL/h/kg, t_1/2?=?1.1?±0.5?h.

Conclusion: The developed HPLC–UV assay is a simple and sensitive method for the determination of vitamins D₃ and K₁ in rat plasma. A higher dose of vitamin K₁ should be used in future studies for accurate estimation of pharmacokinetic parameters. The data show the suitability of the assay for pharmacokinetic studies in rats.