静电纺丝素蛋白组织工程支架的增强改性研究进展

常规静电纺丝法制得的丝素蛋白纤维毡的力学性能较差,不能很好地满足人体对生物组织工程支架的要求。为了提高丝素蛋白组织工程支架的力学性能,对丝素蛋白纤维毡进行增强改性是目前研究的热点。文章简要介绍了丝素蛋白的结构和性能及其在组织工程领域的应用研究,重点总结了提高静电纺丝素蛋白纤维毡力学性能的3种方法,即后处理、添加增强组分以及制备取向纳米纤维。     

超临界二氧化碳相转化技术制备组织工程支架研究进展

组织工程支架是组织工程研究的关键要素之一。然而,传统制备方法存在操作条件复杂或有机溶剂残留量高等问题。本文基于超临界二氧化碳相转化技术操作条件温和、可以将相分离与干燥过程合二为一、有效地去除有机溶剂等优点,简要介绍了超临界二氧化碳相转化技术中应用的组织工程支架材料,具体阐述了制备出具有致密无孔结构、孔洞结构以及三维纳米纤维结构的组织工程支架的研究进展。随后对其目前存在的不足,如该项技术缺少系统的理论研究、部分制备出的支架不利于传质、负载生长因子和细胞粘附等问题提出了可能的解决方案。最后对超临界二氧化碳相转化技术制备具有类似细胞外基质结构和功能、孔洞相互贯通、微观粗糙纳米纤维表面的组织工程支架进行了展望。     

三维打印材料在骨组织工程中的研究进展

骨科手术的需求很大程度上促进了骨组织工程技术的进步。生产用于创伤修复手术的支架材料是一个骨组织工程研究中值得关注和正在进行的研究课题。在支架生产领域,3D打印在微观和宏观结构构建方面具有前所未有的精度,它可以被用来构建各种不同骨及软骨组织修复的生物工程材料支架。本文旨在寻找3DP的各种方法、所用的材料、功能和设计元素,以及改进3DP支架的生物力学性能与生物活性。     

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。     

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。     

定向冷冻明胶支架的原位细菌纤维素培养及支架中的细胞行为

本文以明胶(G)为原料,采用定向冷冻干燥法制备出定向明胶支架,通过原位培养技术在支架引入细菌纤维素(BC)纳米纤维网络,构筑出兼具微米多孔和纳米纤维结构的BC基定向微/纳支架,并使用场发射扫描电镜(FE-SEM)、激光共聚焦显微镜(CLSM)等对支架的微观结构生物学性能进行了表征。结果表明:与非定向支架的多孔结构相比,定向支架具有径向多孔和轴向通道结构,呈现各向异性,这种通道结构有利于氧气和营养物质的输送,能有效促进细胞生长。     

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。     

蚕丝蛋白在生物样本保存领域应用的研究进展

蚕丝是一种天然的高分子材料,由60%~80%的丝素、15%~35%的丝胶及约5%的石蜡、色素、糖类等杂质组成。丝素具有良好的生物相容性和降解性,在药物缓释、促进伤口愈合、组织工程支架等生物医药领域及降血糖、抑菌等医疗保健方面均具有广泛应用;丝胶包裹在丝素纤维外层,对丝素起保护作用,其不仅是非常有用的生物材料,还具有许多生物活性和药理作用,如抗氧化性、抗肿瘤活性、物理胃肠功能等作用。近年,蚕丝蛋白在生物样本保存领域的应用备受研究者关注,本文对蚕丝蛋白在生物样本低温保存和常温保存方面的应用和成果、存在的问题及未来的研究方向作一综述,以期为蚕丝蛋白在生物样本保存领域的应用提供参考。     

组织工程支架材料的研究进展

组织工程支架材料在组织工程研究中起中心作用，它不仅为特定的细胞提供结构支撑怍用，而且还起到模板作用，引导组织再生和控制组织结构。因此，寻找一种既有良好生物相容性和生物降解性又具有特定形状和连通三维多孔结构的支架材料是组织工程的一个重要方面。本文主要对组织工程中常用支架材料的研究进展进行了综述．并对组织工程支架材料目前存在的问题作了分析以及对其发展趋势进行了展望。     

组织工程支架材料研究进展

组织工程支架材料在组织工程研究中起中心作用，不仅为特定的细胞提供结构支撑作用，而且还起到模板作用，引导组织再生和控制组织结构。寻找一种既有良好生物相容性和生物降解性又具有特定形状和连通三维多孔结构的支架材料是组织工程的重要方面。本文概述了几种常用的组织工程支架材料，并对组织工程支架材料目前存在的问题作了分析、对其发展趋势进行了展望。     

Development of a novel glucosamine/silk fibroin–chitosan blend porous scaffold for cartilage tissue engineering applications

Silk fibroin–chitosan blend is reported to be an attractive scaffold material for tissue engineering applications. In our earlier study, we developed a scaffold having an optimal silk fibroin–chitosan blend ratio of 80:20 and proved its potentiality for cartilage tissue engineering applications. Glucosamine is one of the major structural components of cartilage tissue. The present work investigates the effect of glucosamine components on the physicochemical and biocompatibility properties of this scaffold. To this end, varied amounts of glucosamine were added to silk fibroin–chitosan blend with the aim of improving various scaffold properties. The addition of glucosamine components did not show any significant change in physicochemical properties of silk fibroin–chitosan blend scaffolds. The composite scaffold showed an open pore structure with desired pore size and porosity. However, cell culture study using human mesenchymal stem cells derived from umbilical cord blood revealed an overall increase in cell supportive properties of glucosamine-added scaffolds. Cell viability, cell proliferation and glycosaminoglycan assays confirmed enhanced cell viability and proliferation of mesenchymal stem cells. Thus, this study demonstrated the beneficial effect of glucosamine on improving the cell supportive property of silk fibroin–chitosan blend scaffolds making it more potential for cartilage tissue regeneration. To the best of our knowledge, this is the first report on the study of glucosamine-added silk fibroin–chitosan blend porous scaffolds seeded with mesenchymal stem cells derived from umbilical cord blood.     

Comparative study on eri silk and mulberry silk fibroin scaffolds for biomedical applications

Mulberry silk fibroin is being used as biomaterial for tissue engineering applications. In the present work, comparisons are made between mulberry and eri silk fibroin scaffolds prepared by electrospinning method. The scaffolds are treated with ethanol to improve their dimensional stability, and the physical and chemical properties of the scaffolds are assessed using thermogravimetric analyzer (TGA), differential scanning calorimetry, Fourier transform infrared spectroscopy and X-ray diffractometry. The FTIR spectra confirm the structural change of silk fibroin from α-helical to β-sheet structure when mulberry and eri silk scaffolds are treated with ethanol. The thermal stability of the eri silk scaffold is found to be better than that of mulberry silk. Ethanol-treated eri silk displays higher tensile stress than the ethanol-treated mulberry silk. The hemolysis percentages of eri silk and mulberry silk scaffolds are found to be 1 and 3 %, respectively. While the platelet adhesion on eri silk fibroin scaffold is found to be lower than that of mulberry silk fibroin scaffold, the cell attachment, binding and spreading of L6 fibroblast cells on the eri silk scaffold are better than those on the mulberry silk fibroin, and the cell viability is found to be better on eri silk fibroin scaffold.     

Silk fibroin/chitosan/heparin scaffold: preparation,antithrombogenicity and culture with hepatocytes

Antithrombogenicity is very important for tissue engineering scaffolds used in situations involving contact with blood. A silk fibroin/chitosan (SFCS) scaffold has been developed for liver tissue engineering with porous structure, suitable mechanical properties and biocompatibility. Because the interaction between silk fibroin and blood coagulation factors can lead to blood coagulation, the anticoagulant property of the SFCS scaffold should be improved. Heparin was added into SFCS scaffold under mild conditions. The effects of heparin on the morphology, swelling properties, structure, porosity, mechanical properties, antithrombogenicity and cytocompatibility of the SFCS scaffold were studied. SFCS scaffold containing heparin maintains the porous structure and good mechanical properties of the fibroin‐based scaffold; moreover, it is not cytotoxic. Addition of heparin leads to the SFCS scaffold being blood‐compatible and an effective heparin‐delivering system. The anticoagulant property of the SFCS scaffold can be improved by the addition of heparin, which may be helpful for scaffolds used in situations involving contact with blood. Copyright © 2009 Society of Chemical Industry     

三种不同溶剂静电纺丝素纳米纤维的研究进展

静电纺丝素纳米纤维支架材料在组织工程领域具有广阔的应用前景。本文综述了三种不同溶剂静电纺丝素纳米纤维支架材料及其在组织工程领域的研究进展。     

Structures,mechanical properties and applications of silk fibroin materials

For centuries, Bombyx mori silkworm silk fibroin has been used as a high-end textile fiber. Beyond textiles, silk fibroin has also been used as a surgical suture material for decades, and is being further developed for various emerging biomedical applications. The facile and versatile processability of silk fibroin in native and regenerated forms makes it appealing in a range of applications that require a mechanically superior, biocompatible, biodegradable, and functionalizable material. In this review, we describe the current understandings of the constituents, structures, and mechanical properties of silk fibroin. Following that, we summarize the strategies to bring its mechanical performance closer to that of spider dragline silk. Next, we discuss how functionalization endows silk fibroin with desired functionalities and also the effects of functionalization on its mechanical properties. Finally, from the mechanical point of view, we discuss various matrices/morphologies of silk fibroin, and their respective applications in term of functionalities, mechanical properties and performance.     

Preparation of non-woven mats from all-aqueous silk fibroin solution with electrospinning method

In the present study, we successfully prepared non-woven mats from stable regenerated silk fibroin aqueous solution at high concentration. Scanning electronic microscope (SEM) was used to observe the morphology of the fibers. The structure of the fibers was characterized using Fourier transform infrared (FTIR), wide-angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). The mechanical tests were also performed. In the as-spun fibers, silk fibroin was present in a random coil conformation, the stress and strain at break were 0.82 MPa and 0.76%, respectively, while after methanol treatment, the silk fibroin was transformed into a β-sheet-containing structure, the stress and strain at break increased to 1.49 MPa and 1.63%, respectively. This study provided an option for the electrospinning of silk fibroin without using organic solvent or blending with any other polymers, which may be important in tissue engineering scaffold preparation.     

新型丝素复合膜的微结构表征及热稳定性

基于丝素的高分子复合材料可以广泛地应用于组织工程、生物医药和半导体材料等领域。通过物理-共混技术制备了一种新型生物高分子丝素/聚乳酸复合膜。利用扫描电镜、傅里叶红外光谱、拉曼光谱、X射线衍射和热分析技术对其形貌、结构和相态组分以及热稳定性进行了表征,探究了不同比例复合膜的微结构、相互作用机理和热稳定性。结果表明：随着丝素含量的增加,复合膜中的β-折叠含量增多,α-螺旋和无规卷曲含量减少,玻璃化转变温度提高;由于丝素与聚乳酸间的相互作用,提高了复合膜的热稳定性。     

Fabrication and characterization of silk/forsterite composites for tissue engineering applications

In this research, novel composite scaffolds consisting of silk fibroin and forsterite powder were prepared by a freeze-drying method. In addition, the effects of forsterite powder contents on the structure of the scaffolds were investigated to provide an appropriate composite for bone tissue engineering applications. The morphology studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques showed that the forsterite ceramic was well distributed throughout the structures of SF/forsterite scaffolds. Furthermore, the forsterite powder (up to 40 wt%) was homogenously distributed within the silk fibroin as a matrix.     

A novel silk fibroin/sodium alginate hybrid scaffolds

Porous silk fibroin/sodium alginate hybrid scaffolds were prepared through lyophilization method. Hybrid scaffolds were characterized for morphological and functional properties related to different mixture ratios between silk fibroin and sodium alginate. The silk fibroin/sodium alginate hybrid scaffolds showed a thin‐layer structure and much more irregular rod‐like structure appeared at the layer surface after adding 50% sodium alginate. The results of wide‐angle X‐ray diffraction and Fourier transform infrared analysis confirmed that the crystal structure of silk fibroin was not influenced by adding the different contents of sodium alginate, exhibiting the random coil structure in the hybrid scaffolds. The thermal behavior of the hybrid scaffolds exhibited major change with containing 30% sodium alginate or more. The porosity of the scaffolds varied between 92 and 94% with a favorable compressive modulus and stress. The mechanical properties results depicted the hybrid scaffolds containing 10% sodium alginate, with a porosity of 94.0 ± 0.10%, attained the highest compressive modulus and stress for 41 ± 6 and 44 ± 3 kPa, respectively. In addition, mineralization results showed hydroxyapatite crystal growing on the surface of the scaffold. This hybrid biomaterial should offer new and important options to the needs related to biomineralization and tissue engineering, in general. POLYM. ENG. SCI., 54:129–136, 2014. © 2013 Society of Plastics Engineers