Nanoscale control of silks for regular hydroxyapatite formation

The control of nanoparticle shape is still a challenge for different hydroxyapatite (HA) preparation ways.In the present study,silk fibroin with regular nanostructures was firstly prepared and then emp...     

Examination of Subunit Composition of Bombyx Mori Silk Fibroin

Main subunits of the silk fibroin were separated by GFC(gel filtration chromatography)technigue.The nativesilk fibroin and α,c subunits were measured by gel elec-trophoresis.The aminoacid compositions of the nativesilk fibroin and α,c subunits were analyzed by means ofaminoacid measurement.Some properties of silk was inter-preted in view of subunit composition of silk fibroin.     

Biological and mechanical investigation of novel flax/silk protein-based nanofibrous scaffold for bone regeneration

The process of bone tissue regeneration involves an intricate network of a biological macromolecules that includes proteins and peptides to support stimulation and healing response. Here, we have fabricated a novel flaxseed/silk fibroin based (dual protein) composite nanofibers using β-TCP to improve the biological properties and promote cartilage tissue regeneration along with a controllable rate of biodegradation. The physiochemical properties of PVA/β-TCP/FP:SF were characterized by FTIR, XRD, SEM, porosity, contact angle measurements and mechanical evaluation etc. This study demonstrates the biological performance of the developed nanofibers by using hemocompatibility, biodegradation ability, and apatite deposition in stimulated body fluid. Moreover, the cell viability assay was performed on MG-63 osteoblast cells and long-term antibacterial rate against E. coli and S. aureus was analysed. Docking results of flax protein and silk fibroin protein further confirmed the stable modes of intramolecular bonding and the most stable electrostatic values using theoretical calculations. Taken together, the experimental results proved that the dual protein-based fibrous scaffold was found to be up-regulated in terms of biological activity with enhanced cell adhesion and proliferation.     

多孔柞蚕丝素支架的制备及其在药物缓释中的应用

采用冷冻干燥法制备了多孔柞蚕丝素支架,分析了丝素溶液浓度与支架孔径、孔隙率之间的关系,并研究了多孔柞蚕丝素支架负载5-氟尿嘧啶的缓释性能.研究表明,当丝素浓度较低时,支架中的孔洞分布较为均匀,孔径和孔隙率也较大,而随着丝素溶液浓度增大,支架的孔径和孔隙率逐渐减小;支架的药物释放过程可分为快速释放和缓慢释放两个阶段.     

天然丝素制备三维多孔支架

研究盐沥滤法制备三维多孔丝素支架,在丝素多孔支架上培养人成骨肉瘤细胞、成纤维细胞及肝细胞.研究材料的细胞相容性,发现多种动物细胞在盐沥滤法所制备的丝素多孔支架材料上能够很好地黏附和增殖.通过调整丝素水溶液的浓度、溶解丝素溶剂体系、NaCl添加量和NaCl粒径,制备出结构和性质可以调控的三维支架.该结果为丝素多孔支架材料的制备提供了新的研究思路和方法.     

明胶/丝素共混多孔膜的制备

采用冷冻干燥法制备明胶与家蚕丝素的共混多孔蛋白膜，探讨了交联剂用量，共混比例及冷冻温度对膜结构和性能的影响，指出戊二醛对共混多膜具有明显的交联作用，膜内丝素与明胶的相容性较好，蛋白质的结构以无定形为主，通过与明胶共混，能够改善多孔丝素膜的拉伸性能。     

Fine Structure of Regenerated Silk Fibroin Solids

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丝素在NMMO·H2O中的溶解及溶液流变性能的研究

探讨了丝素在N-甲基吗啉-N-氧化物一水合物(NMMO.H2O)中的溶解行为,结果发现:天然蚕丝纤维脱胶后得到的丝纤维可以直接溶解在NMMO.H2O中,但是很难得到高于10%浓度的溶液,因而无法用于纺丝.而由再生丝素水溶液制得的再生丝素膜则易于溶解在NMMO.H2O中,并可以得到浓度高达25%的再生丝素/NMMO.H2O溶液,在上述研究的基础上,本文还对再生丝素/NMMO.H2O的流变行为进行了初步研究.     

高含量再生丝素蛋白水溶液的热性能研究

用差示扫描量热仪(DSC),对不同含量的再生丝素蛋白水溶液(质量分数为12%~42%),以及同一含量不同剪切速率(1 000 s-1和2 000 s-1)下溶液热性能的变化进行了对比研究。结果表明,随着含量的增大,再生丝素蛋白水溶液发生相转变的温度逐渐降低;同样,经剪切后的溶液发生相转变的温度均向低温漂移,且随着剪切作用的加强,向低温的漂移越明显。试验表明,丝素水溶液含量的增加和剪切作用可加速溶液从无规线团或α-螺旋向β-折叠构象的转变速度,且随着剪切速率的提高,构象转变的速度也加快。     

Preparation and Characterization of Silk Fibroin Aerogel

Silk protein fibroin,as a biomedical material,has good biocompatibility,biodegradability,regulation and excellent physical and chemical properties. In this work,a low density porous silk fibroin material is prepared from fibroin solution by high-speed shearing with impeller. By adjusting shear rate of the stirrer,silk fibroin aerogel with different sizes of the aperture is prepared. In general, this aerogel has small porosity, uniform pores, good mechanical properties and slow rate of degradation. It is observed that increasing the shear rate results in higher porosity of aerogel,while the diameter of the aerogel becomes smaller. This silk aerogel may offer a new option as biomaterial for the tissue engineering application based on the information on the structural behaviors.     

Preparation of insoluble fibroin films and its tensile property

Silk fibroin is becoming a promising biomate-rial because of its excellent biocompatibility. However, theregenerated fibroin is usually soluble in water and its me-chanical properties should be improved. Although manymethods, such as adding other polymers or treating withmethanol, can ameliorate the mechanical properties andinsolubility, the biocompatibility of fibroin is usually dam-aged in these processes. In this article, it is first reported thatthe insoluble fibroin films are directly prepared withoutmethanol treatment. According to the results of Fouriertransform infrared spectroscope (FTIR) and the X-ray dif-fraction (XRD), the amount of IS-sheet conformation in-creased with the increasing of concentration. When fibroinfilms are dried from 15 wt% at 60℃, the films become in-soluble in water. More importantly, The tensile strength andelongation of the insoluble fibroin films dried from 15% so-lution at 60℃ reached 15.9 MPa and 49.4% respectively in the wet state, which is distinctly superior to the fibroin films treated with methanol.     

Preparation of 3-D porous fibroin scaffolds by freeze drying with treatment of methanol solutions

In this study, silk scaffolds with appropriate porous structures were prepared by adjusting solution concentrations and providing treatment with methanol solutions in the way of freeze drying. The effects of the preparation conditions on the microstructures and properties of the scaffolds were discussed. Fibroin solutions with different concentrations of 4, 6, 8, 10 wt% were used respectively to prepare the scaffolds. The effects of the addition of 20 vol% methanol before or after freeze drying to the 4 wt% fibroin solution were investigated. As demonstrated by Scanning Electron Microscope (SEM), the fib-roin scaffolds prepared without methanol had porous microstructures composed of thin sheets, and the sizes of the pores decreased with the increase of the fibroin solution concentrations, while the scaffolds prepared in the presence of methanol showed porous microstructures formed by fine-particle aggregates. The porosities and mechanical properties of the prepared fibroin scaffolds under different conditions were tested. The crystalline structures and conformations of the fibroin scaffolds were detected by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).     

家蚕丝素溶液的粘弹性研究

采用Coucttc流变仪对家蚕丝素溶液的粘弹性进行研究。对于生丝丝素溶液,当丝素浓度较稀时(如4w/v％),溶液表现出牛顿流动行为;当丝素浓度较高时(如25W/V％),溶液表现出复杂的非牛顿流动行为。成烈的家蚕丝腺中的丝素,在剪切速率大于0.25s~1时,能引起纤维化。     

丝素在生物医学领域中的应用

讨论了丝素（silk fibroin,SF)与生物医学领域应用相关的基本性质，以及在生物分析及药物缓释载体，人工器官及组织工程支撑体材料中的应用现状，结论认为：丝素具有固化结晶方式的多样化。易于保持高度生物亲和性以及形成特殊的多孔性网状结构。丝素还具有优良的成膜特性，并且通过与其它一些天然高分子材料的复合与化学改性，可以进一步改善其物理性能，从而适宜于构建新型药物载体与人工器官，同时，针对丝素蛋白在体的生物相容性，在体降解特性方面存在的问题，认为其在体变化机制不仅取决于与之接触体液的化学构成，也与温度，力学环境等生物物理因素有关，因此其在体变化机制是生物力学与生物流变学的因素与生物化学因素协同控制的。     

丝素蛋白在组织工程中的应用

丝素蛋白作为一种具有优良生物相容性的天然高分子材料在生物医用领域有着广泛的应用，着重阐述了丝素蛋白在组织工程领域中应用研究的最新进展。     

Physico-Chemical Properties of a Water-Insoluble Silk Fibroin Film

The conventional silk fibroin(SF)films obtained by casting from SF aqueous solution are amorphous,and easily dissolved in water.This defect limits the practical use of SF films in biomedical field.A new water-insoluble silk fibroin film(an SF-FA film)could be simply prepared by casting from SF formic acid solution.The physical properties and moisture permeability of SF-FA films were examined.The results show that the SF-FA film swollen in water exhibits outstanding pliability.The weight loss of SF-FA films ...     

IMPROVEMENT OF WET-CREASE RECOVERY PROPERTIES OF SILK FABRICS TREATED WITH EPOXIDES

Silk fabrics is finished with epoxide TDEA or TDEB. By the determination of washing fastness, DSC, IR spectrum and amino acid contents tests, TDEA or TDEB is confirmed to react with silk fibroin. By means of tests of silk fibroin swelling and solubility in some solvents, crosslinking reactions between TDEA or TDEB and silk fibroin arc further proved, which is obviously responsible to the increase of wet-crease recovery of silk fabrics finished with epoxide TDEA or TDEB.     

TDEA、TDEB 提高丝绸湿弹性机理的研究

采用自制的整理剂 TDEA 和 TDEB 对丝绸进行整理。通过耐洗率度,DSC、红外光谱和氨基酸分析测试证明 TDEA、TDEB 与丝素发生了化学反应;并通过丝素的溶胀试验、溶解度试验进一步证明TDEA、TDEB 与丝素发生了共价交联反应,从而可以认为 TDEA、TDEB 与丝素间发生共价交联作用是使丝绸湿弹性获得显著提高的主要原因。     

稀土固着丝胶增重真丝纤维的结构变化

用稀土金属离子通过形成配位结合来固着丝胶，制备了不同增重率的丝纤维，研究了增重丝纤维结构变化。与未增重丝纤维相比，增重丝纤维的纵向形态和截面形态发生了变化，增重丝纤维中氮元素和碳元素的含量呈下降趋势，增重丝纤维中极性氨基酸含量增加，增重丝纤维的结晶度随着增重率的增加而下降，增重丝纤维热分解峰顶温度变化不明显。     

Structure and Property of Silk Fibroin ／ Cellulose Blend Film

Silk fibroin/cellulose blend films were prepared using Nmethylmorpholine-N-oxide (NMMO) as solvent. The effects of different proportions and solid contents on properties of blend films were discussed. The mechanical properties showed that the blend films had preferable moisture permeability and a high strength. The structures of the blend films were investigated by infrared spectrum and X-ray diffraction. The results indicated the occurrence of hydrogen bonds between hydroxyl groups of cellulose and amido groups of fibroin.