响应曲面法优化再生丝素蛋白/多壁碳纳米管共混水溶液静电纺丝工艺

再生丝素蛋白/多壁碳纳米管共混水溶液静电纺纤维毡可应用于组织工程支架。提高纤维毡的孔隙率即减小纤维的横截面尺寸有利于细胞的粘附和增殖,从而提高材料的应用性能。该文采用响应曲面法(RSM)优化再生丝素蛋白/多壁碳纳米管共混水溶液静电纺丝工艺,以减小纤维横截面尺寸。     

静电纺丝素纳米纤维在生物医学组织工程领域的研究进展

利用静电纺丝技术以丝素蛋白为主要原料制备直径与天然细胞外基质(ECMs)结构相近的纳米纤维,使丝素蛋白支架能够较好地仿生人体内ECMs结构,让种子细胞可在支架多孔三维网络状结构上很好地黏附、增殖,并提供细胞基质、维持细胞生长并保持分化功能,满足组织修复和重建的要求,是目前生物技术应用医学领域的研究热点。本文主要综述了近年来国内外静电纺丝制备丝素蛋白纳米纤维材料在组织工程领域应用的研究现状,并对静电纺SF纳米纤维未来应用的发展作了展望。     

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。     

静电纺再生丝素纳米纤维的结构与性能

静电纺丝获得的丝素纳米级纤维可作为细胞培养支架,用于纺丝工艺及后处理能改变丝素微细结构,影响其水溶性和力学性能。本文采用XRD、FTIR、固态13CNMR和DSC研究了不同工艺下丝素纳米纤维及经甲醇处理后的微细结构,比较了不同微细结构下的水溶性和力学性能。结果表明,电纺丝的微细结构受纺丝工艺影响,高电压、纺丝液中丝素质量分数大时纺得的电纺丝结晶度高,经甲醇处理后,β化程度提高;w(丝素)=11%、15%时制备的电纺丝断裂强度分别为8.5、11.9 cN/mm;w(丝素)=11%、19%,水溶性由51.2%下降到43.3%;w(丝素)=19%、电压32 kV制得的电纺丝甲醇处理前后水溶性从43.3%下降到6.6%,说明丝素纳米纤维结晶度提高,强度增加、水溶性下降,满足了细胞支架的要求。     

静电纺丝SF/PLGA纤维支架用于血管组织工程的研究

将丝素蛋白（SF）和乳酸-羟基乙酸共聚物（PLGA）溶解在六氟异丙醇中配制成溶液,采用静电纺丝技术制备了SF/PLGA纳米纤维支架,使用扫描电子显微镜（SEM）对纤维支架进行表征,研究了聚合物溶液浓度、纺丝电压、接收距离以及体积流率对纳米纤维形态的影响,从而得到纺丝的最适宜工艺参数。考察了纤维支架表面对HUVECs细胞的相容性。结果表明：HUVECs可以在SF/PLGA纤维支架表面很好的黏附和增殖,支架具有良好的细胞相容性,在组织工程领域有良好的应用前景。     

聚氨酯的静电纺丝

简述了聚氨酯(PU)的特性;分析了PU静电纺丝的可纺性影响因素;论述了静电纺丝PU纤维的特性及应用领域。指出PU具有较好的可纺性,PU纤维具有优异的力学性能,应用前景广阔。建议PU静电纺丝应从静电纺丝工艺参数、利用静电纺丝制备组织工程支架、纤维抗菌功能改性等方面进行更深入的研究。     

静电纺丝法制备丝素蛋白/季铵盐壳聚糖复合纤维支架

将丝素蛋白(SF)水溶液和季铵盐壳聚糖(HACC)水溶液以100∶0、99∶1、98∶2和97∶3的溶质比共混作为纺丝液,测试了其质量分数为30%时的表面张力和电导率,并通过应力控制流变仪对其静态剪切和动态剪切作用下的流变性能进行了分析。采用静电纺丝技术制备出静电纺SF/HACC复合纤维支架,通过扫描电子显微镜对其表面形貌进行表征。结果表明,随着HACC含量的增加,纺丝液的黏度和电导率逐步提升;HACC能促进纺丝液的凝胶化;得到的静电纺纤维支架有着较均一的形貌,纤维较扁平,在组织工程修复领域具有良好的应用前景。     

再生丝素蛋白-羟丙基壳聚糖静电纺纤维毡的研究

采用静电纺丝方法制备了再生丝素蛋白-羟丙基壳聚糖初生纤维毡并对其进行了乙醇后处理。通过扫描电镜、拉曼光谱、X射线衍射及各种性能分析手段研究了初生纤维毡和（或）后处理纤维毡的结构与性能。研究发现：随着羟丙基壳聚糖含量的增多,初生纤维毡中的纤维直径总体有减小的趋势,形貌由圆柱形纤维居多逐渐变成扁带状纤维居多,但仍以无规卷曲/α-螺旋构象和无定形结构为主,而后处理纤维毡的β-折叠构象含量、结晶度和力学性能均呈现先提高后下降的趋势,细胞增殖活性则逐渐增大,生物相容性随之提高。     

微观结构与组织工程丝素支架研究进展

丝素蛋白因其具有良好的生物相容性、生物可降解性以及卓越的力学性能而被广泛应用于组织工程。为了促进丝素支架更利于细胞的黏附和增殖、促进新的细胞外基质生成、组织向内生长以及利于营养物质及代谢产物的运输等,丝素支架微观结构的构建仍是组织工程的一个重大挑战。本文着重围绕丝素支架的微观结构展开,介绍了多孔结构、纤维结构、多孔-纤维结构和水凝胶结构近年来在组织工程中的应用,从不同支架结构制备方法及功能方面并结合作者实验相关工作对比分析了不同支架结构的优势和存在的问题以及对细胞的影响,指出应从分子水平及原子水平上研究天然组织的结构来精准、有效地体外模拟构建组织工程丝素支架。     

丝素蛋白在骨组织工程中的应用研究进展

简述了骨组织工程的重要性及其对组织工程支架的要求,介绍了丝素蛋白的特性,着重介绍了5种形态的丝素蛋白材料在骨组织工程中的应用,并总结了丝素蛋白复合支架的特点以及其对骨修复的影响,提出了丝素蛋白支架存在的主要问题并展望了其未来的研究方向。     

In vitro biocompatibility of electrospun silk fibroin mats with Schwann cells

In this study, electrospinning was used to fabricate silk‐fibroin (SF)‐based mats, which served as substrates for the culturing of rat Schwann cells. Microscopic observation and physical parameter measurements revealed that the electrospun SF mats had a nanofibrous structure with favorable physical properties. Fourier transform infrared analysis provided chemical characterization of the molecular confirmation of the SF proteins in the mats. The morphology and immunocytochemistry showed that the mats supported the survival and growth of the cultured Schwann cells, and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide analysis indicated that the electrospun SF mat extract had no cytotoxic effects on Schwann cell proliferation. Collectively, all of the results suggest that the electrospun SF mats might become a candidate scaffold for tissue‐engineered nerve grafts to promote peripheral nerve regeneration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Magnetic silk fibroin composite nanofibers for biomedical applications: Fabrication and evaluation of the chemical,thermal, mechanical,and in vitro biological properties

Magnetically responsive polymer composites have great potential for use in diverse biomedical applications. In this study, composite biomaterials consisting of silk fibroin (SF) and superparamagnetic iron oxide nanoparticles (SPIONs) were fabricated by the electrospinning method. Two different methods were employed to incorporate the SPIONs into the SF nanofibers. In the first encapsulation method (M1), SPIONs (1.0, 3.0, and 5.0 wt%) were initially included in the electrospinning solution. In the second dip-coating method (M2), electrospun SF nanofiber mats were immersed in the aqueous suspensions of SPIONs (10, 30 and 50% v/v). Then, the pure and composite silk fibroin composite mats were comparatively evaluated for their morphological, chemical, magnetic, mechanical and in vitro biological properties, by using a number of methods including SEM, TEM, FTIR, XRD, EDS, VSM, TGA, mechanical tensile tests, as well as by indirect in vitro cytotoxicity and in vitro hemocompatibility analyses. Overall findings suggested that, while M1 nanofiber mats could be a suitable candidate for use in tissue engineering as a magnetically responsive cytocompatible scaffold, the M2 nanofiber mats perhaps could be more appropriate as an interface for triggering the in vitro stem cell differentiation and/or biosensor applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48040.     

Poly(l-lactide-co-?-caprolactone) electrospun nanofibers for encapsulating and sustained releasing proteins

The aim of this study was to investigate coaxial electrospun poly(l-lactide-co-?-caprolactone) [PLLACL] nanofibers for the application in nerve tissue engineering. The hypothesis was that the nanofibrous mats fabricated by coaxial electrospun PLLACL could be effective scaffolds for releasing proteins, such as Bovine Serum Albumin (BSA) or/and Nerve Growth Factor (NGF), in a sustained manner. To test the hypothesis, the coaxial electrospun nanofibers with PLLACL as the shell and BSA/NGF as the core were characterized. Morphologies and mechanical properties of nanofibrous mats were examined. BSA released behavior was studied. The results demonstrated that BSA could be sustainedly released from coaxial electrospun PLLACL nanofibers, however, BSA released from mix electrospun nanofibers present the burst release behavior. Bioactivity of released NGF from coaxial electrospun nanofibers was verified by testing the differentiation of rat pheochromocytoma cells (PC12).     

Effect of organic solvent on morphology and mechanical properties of electrospun syndiotactic polypropylene nanofibers

We study the stress–strain behaviors of the electrospun sPP single nanofibers as well as nonwoven mats, which were electrospun from sPP solutions using two different solvents (decalin and cyclohexane) by electrospinning. The effects of organic solvents were explored on the morphologies and the mechanical properties of the corresponding electrospun sPP single nanofibers and nonwoven mats. It was found that the nature of organic solvents dramatically affected the surface morphologies, the circular and looping deposition of the electrospun sPP fibers, and the mechanical properties. The tensile strength of both electrospun sPP single nanofibers and nonwoven mats prepared from decalin-base solution was stronger than that of cyclohexane-base solution.     

PLGA/SF blend scaffolds modified with plasmid complexes for enhancing proliferation of endothelial cells

Biomimetic scaffolds have been investigated for vascular tissue engineering for many years. However, the design of an ideal biodegradable vascular scaffold is still in progress. The optimization of poly(lactide-co-glycolide)/silk fibroin (PLGA/SF) blend composition was performed to provide the designed scaffolds with adequate mechanical properties and favorable biocompatibility for the intended application. By systematically varying the weight ratio of PLGA and SF, we could control fiber diameter and hydrophilicity as well as mechanical properties of the fibrous scaffolds. These scaffolds with a weight ratio of PLGA/SF at 70/30 exhibited excellent performance, such as tensile strength of 1.5 ± 0.1 MPa, and elongation at break of 77.4 ± 6.4%. Therefore, PLGA/SF scaffold with a weight ratio of 70/30 was chose as the matrix because it matches at best the mechanical demands for application in vascular tissue engineering. In order to promote the endothelialization of electrospun scaffolds, we used pEGFP-ZNF580 plasmid (pZNF580) complexes to modify the electrospun scaffolds by electrospraying technique. pZNF580 complexes were prepared from pZNF580 and microparticles (MPs) of amphiphilic copolymer methoxy-poly(ethylene glycol)-block-poly(3(S)-methyl-2,5-morpholinedione-co-glycolide)-graft-polyethyleneimine. Negatively charged PLGA/SF fibers adsorbed the positively charged MPs via physical deposition and electrostatic force. Scanning electron microscope image indicated the forming of composite scaffold and MPs did not change fiber’s shape and 3-D structure. Cell culture experiments demonstrated that the scaffolds modified with MPs/pZNF580 complexes could promote human umbilical vein endothelial cell growth and inhibit human umbilical artery smooth muscle cell proliferation. Our results indicated that the composite scaffolds with MPs/pZNF580 complexes could be used as a potential scaffold for vascular tissue engineering.     

Coloration of cellulose nanofibres with pigments

Electrospun nanofibrous mats are popular for their wide technological applications as medical, filtration, sensing and high performance textiles. The potential for coloration of electrospun nanofibrous mats for aesthetic purposes has also been explored recently, and the pigment coloration of cellulose electrospun nanofibrous mats is reported for the first time in this paper. Cellulose acetate electrospun nanofibrous mats were fabricated using electrospinning followed by treatment with sodium hydroxide to synthesise regenerated cellulose electrospun nanofibrous mats. Then the cellulose mats were coloured with commercially available pigments by a pad‐dry‐bake method. Excellent K/S and colour fastness to both washing and light were produced with the application of three commercial pigments. The pH and total dissolved solids content of the coloration wastewater, as well as the mechanical properties of the electrospun nanofibrous mats, were also tested. Attenuated total reflection‐Fourier Transform infrared spectroscopy and scanning electron microscopy analysis were used for characterisation.     

Fabrication of patterned PDLLA/PCL composite scaffold by electrospinning

Fabricating fibrous electrospun scaffolds with controllable fiber‐arrangement have gained an increasing attention in the field of tissue engineering. In this study, the composite patterned D,L ‐poly(lactic acid)/poly(ε‐caprolactone) (PDLLA/PCL) scaffolds were fabricated via electrospinning for the first time, and the order degree and contractibility of patterned composite scaffolds with different PDLLA/PCL ratios were further investigated. The results showed that the order degree of the pattern and in vitro shrinkage behaviors of PDLLA/PCL electrospun mats could be finely tuned by controlling blending ratios. The PDLLA/PCL electrospun mats with the ratio 50/50 showed the most balanced properties with controllable pattern structure and appropriate dimensional stability, and they might be a suitable candidate for tissue engineering application. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Mechanical property enhancement of non‐bonding electrospun mats via adhesive

In the present study, the effect of adhesive on the morphology of different electrospun polymeric mats was investigated. The modification of two polymers, poly(methyl methacrylate) and poly(vinyl chloride), was carried out by blending the polymers with different amounts of poly(butyl acrylate) (PBA) adhesive to investigate the effect of different amounts of adhesive with heat hardener in hybrid mats. The introduction of various concentrations of PBA into different polymer solutions led to the formation of point‐bonded electrospun fibrous mats. Scanning electron microscopy images indicated that point‐bonded polymer/adhesive fibers were uniformly distributed throughout the mats. Fourier transform infrared spectrometry, contact angle measurements and thermogravimetric analysis were used to study the different properties of the hybrid mats. The tensile strength of the blended fibrous electrospun mats was increased effectively. This enhancement of the mechanical properties of the mats due to the presence of adhesive increases the number of potential applications of the electrospun mats, especially for mechanically weak polymers. Copyright © 2012 Society of Chemical Industry     

Crosslinked,electrospun chitosan–poly(ethylene oxide) nanofiber mats

Mechanical characterization of nanofiber mats is an underexplored area in biomaterial engineering. In this study, a chitosan–poly(ethylene oxide) copolymer blend was electrospun and crosslinked with glutaraldehyde (GA) for various time periods. The tensile and compressive mechanical integrity of the nanofibers was analyzed with increasing exposure to vapor crosslinking. Solubility, scanning electron microscopy characterization, Fourier transform infrared, uniaxial tensile tests, and nanoindentation analyses were used to identify these trends. The mechanical studies confirmed that the GA vapor crosslinking increased the stiffness and decreased the ductility of the electrospun mats. Increased exposure time to crosslinking led to changes in the mat surface color and resistance to dissolution. Scanning electron microscopy fiber counts verified that exposure to GA vapor crosslinking increased the average fiber diameter. By the use of vapor phase deposition, mechanical properties continued to change throughout the study. The crosslinking exposure time could be chosen to accommodate in vivo mechanical loading. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mechanical and tribological properties of electrospun PA 6(3)T fiber mats

The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a large number of applications. Although some mechanical properties of these mats have been reported previously, reports of their tribological properties are essentially nonexistent. In this work, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) with average fiber diameter of 463 ± 64 nm are characterized mechanically and tribologically. Post-spin thermal annealing was used to modify the properties of the fiber mats. Morphological changes, in-plane tensile response, friction coefficient and wear rate were characterized as functions of the annealing temperature. The Young's moduli, yield stresses and toughnesses of the nonwoven mats improved by two- to ten-fold when annealed slightly above the glass transition temperature, but at the expense of mat porosity. The coefficient of friction and the wear rate decrease by factors of two and ten, respectively, under the same conditions. The wear rate correlates with the yield properties of the mat, in accord with a modified Ratner–Lancaster model. The variation in mechanical and tribological properties of the mats with increasing annealing temperature is consistent with the formation of fiber-to-fiber junctions and a mechanism of abrasive wear that involves the breakage of fibers between junctions.