酸解家蚕丝的光谱性质及其抑菌试验初步探究

用磷酸水解蚕丝得到丝素肽,对金黄色葡萄球菌和大肠杆菌进行抑菌试验。结果表明,丝素肽的结构是无定形的,不同浓度的丝素肽对这两种细菌均有不同程度的抑制作用,可作为食品与化妆品的防腐剂使用。     

纳米氧化石墨烯添食育蚕制备高强度蚕丝

本文采用添食育蚕法,向五龄期家蚕喂食纳米氧化石墨烯(GO)改性的人工饲料制备改性蚕丝。利用扫描电子显微镜、红外光谱、广角X射线衍射等技术对改性前后蚕丝的结构及性能进行表征。结果表明,GO被成功导入丝素蛋白,未明显影响蚕丝表面形貌,但限制了丝素蛋白二级结构转变及结晶,明显提升了蚕丝的力学性能。     

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。     

丝素肽的制备及其润肤保湿成效

本文以天然蚕丝为原料,经盐解制得分子量约为14500的丝素肽,在经碱性蛋白酶水解成分子量约为1500的丝素短肽。体外透皮实验表明,24 h内丝素肽的透皮率为7.1%,丝素短肽的透皮率为47.8%。研究润肤保湿成效表明,擦涂含丝素肽的膏霜,在8 h内皮肤角质层的水分增加13.1%以上,4 h内皮肤经皮水分流失减少26.6%以上;擦涂含丝素短肽的膏霜,在8 h内皮肤角质层的水分增加17.5%以上,4 h内皮肤经皮水分流失减少19.3%以上。     

蚕丝蛋白聚氯乙烯混合膜的制备及性质研究

对聚氯乙烯树脂与家蚕丝素蛋白共混膜的吸湿、热力学和染色等性能进行了研究。混合膜的酶降解特性、水分吸收和热稳定性比丝素单一膜有了较大的改进。该膜染色的外观和天然丝素膜一样透明,但其力学性能随着家蚕丝素蛋白比率的增加而下降明显。研究表明丝素蛋白粉可作为塑料的生物崩解过程的催化剂。     

废蚕丝中丝素蛋白的琥珀酰化改性研究

文章研究采用琥珀酰酐对废蚕丝丝素蛋白进行化学改性,研究丝素蛋白浓度、琥珀酰酐用量、反应温度、反应时间对丝素蛋白琥珀酰化程度的影响。通过正交实验确定丝素蛋白琥珀酰化的适宜条件为:丝素蛋白浓度2%、琥珀酰酐用量15%、温度40℃、反应时间30 min。丝素蛋白经琥珀酰化修饰后,起泡特性与乳化特性与原来相比均有不同程度的改善。     

紫外荧光蚕丝的添食育蚕法制备及结构性能研究

本文以蚕腺体为生物反应器,通过喂食法将稀土紫外长波长荧光粉(BAM)引入蚕丝。利用扫描电子显微镜、荧光显微镜、红外光谱仪、广角X射线衍射及材料试验机等对纤维的形貌、结构及性能进行了表征。结果表明,BAM进入了蚕丝,纤维在紫外光激发下发蓝色荧光;BAM的导入影响了蚕丝的表面形貌,限制了丝素蛋白的结晶,降低了蚕丝的力学性能。     

蚕丝不同溶解方法的研究

以不同的溶解体系来溶解蚕丝,根据凝胶化时间和粘度法等手段来分析各溶解体系的不同,并用傅里叶红外光谱法(FT IR)对不同的体系进行表征.结果表明:不同溶解体系来溶解蚕丝,所得出的丝素溶液的稳定性,特性粘度和二级结构都是不同的,从而得出蚕丝不同溶解体系的应用范围.     

天然丝素在化妆品中的护肤特性及应用

天然丝素是世界上最受欢迎的天然型营养化妆品添加剂之一。蚕丝经处理、加工可制成丝素粉、丝肽液、丝胶冻及丝素氨基酸等,本文详细阐述了这几种产品的加工、性能及作用机理,并提供了详细的应用配方。     

蚕丝蛋白水解工艺及作为化妆品添加剂的应用研究

蚕丝蛋白是一种新型化妆品添加剂,含有多种氨基酸和蛋白质,无毒、副作用,具有很广泛的应用价值。研究了蚕丝水解液的制备工艺及水解过程中pH、温度、反应时间对水解程度的影响。结果表明,pH越高,蚕丝蛋白水解程度越大,收率越高。较高的温度可使蚕丝蛋白水解速度加快,但水解液颜色较深,较低的温度,水解速度较慢。反应时间越长,蚕丝蛋白水解程度越大。并介绍蚕丝水解液在化妆品中的添加方法及如何解决试验过程中存在的实际问题。     

Sulfation of silk fibroin by sulfuric acid and anticoagulant activity

Silk fibroin (Bombyx mori) was sulfated with an aqueous sulfuric acid solution. The sulfated fibroin was characterized by Fourier transform infrared spectroscopy (FTIR), amino acid analysis, and gel filtration chromatography (GFC). Maximum yield was obtained at around 2–4 h, and it decreased at 6 h and more. The molecular size decreased and dispersed with sulfation, and the molecular weight was estimated at around 10,000 by GFC using protein standards. The amino acid composition indicated that the crystal region of the fibroin molecule remained in sulfated fibroin until a sulfation reaction time of 4 h. The incorporation of sulfate groups was confirmed by FTIR and the amount of sulfate groups introduced for 4 h sulfation was estimated in 0.3 mmol/g by acidimetric titration. The efficiency of sulfation was calculated at 15.7%. Blood coagulation was prevented by 20 mg of sulfated fibroin in 1 mL of blood, while original fibroin did not show the effect. This result indicates that sulfate group introduction results in addition of anticoagulant function to silk fibroin. Although a variety of polymer backbones have been used for synthesis of sulfated polymers as anticoagulant materials, no reports are available concerning a sulfated polymer based on a protein backbone. Sulfated fibroin is a new type of anticoagulant material having a protein backbone. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2377–2382, 2003     

Effects of superfine silk protein powders on mechanical properties of wet‐spun polyurethane fibers

Mechanical measurements were employed to investigate the effects of three types of superfine silk protein powder on tensile strength, elongation, and elasticity of wet‐spun Pellethane^® 2363‐80AE polyurethane (PU) fiber. These superfine silk protein powders included undegummed silk (with both native silk fibroin and sericin, water insoluble), native silk fibroin (with native silk fibroin only, water insoluble), and regenerated silk fibroin (with regenerated silk fibroin only, water soluble) in powder form. Experimental data derived from the mechanical measurements illustrated that the miscibility between the PU and regenerated silk fibroin were superior to that between PU and the other two silk proteins. This may be attributed to the similar chemical structure and microphase separation of PU and regenerated silk fibroin with lower molecular weight than native silk fibroin. This preliminary work may provide some information for biomimetic processing of silk‐inspired PU biofibers, which combine elasticity of synthetic PU with biofunction of natural silk fibroin for special biomedical applications. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Dyeing properties of silk produced by silkworms reared on artificial and mulberry leaf diets

The dyeing properties were investigated for silk proteins produced by silkworms reared entirely on an artificial diet (A) and a mulberry leaf diet (M). The dyeing experiments were carried out with CI acid orange 7 at pH 3.9 and 60°C. The sericin contents of the A and the M raw silk samples were determined to be 26.0% and 23.7%, respectively. The equilibrium dye uptake and the dyeing rate of the A silk fibroin were almost the same as those of the M silk fibroin. The equilibrium dye uptake on each silk sericin was 3–4 times higher than that of the silk fibroin. On the other hand, the equilibrium dye uptake of the A silk sericin was higher than that of the M silk sericin, but the dyeing rate of the former was slower than that of the latter.     

Electroactive Silk Fibroin Films for Electrochemically Enhanced Delivery of Drugs

Biomaterials capable of controlling the delivery of drugs have the potential to treat a variety of conditions. Herein, the preparation of electrically conductive silk fibroin film‐based drug delivery devices is described. Casting aqueous solutions of Bombyx mori silk fibroin, followed by drying and annealing to impart β‐sheets to the silk fibroin, assure that the materials are stable for further processing in water; and the silk fibroin films are rendered conductive by generating an interpenetrating network of a copolymer of pyrrole and 3‐amino‐4‐hydroxybenzenesulfonic acid in the silk fibroin matrix (characterized by a variety of techniques including circular dichroism, Fourier‐transform infrared spectroscopy, nuclear magnetic resonance, Raman spectroscopy, resistance measurements, scanning electron microscopy‐energy dispersive X‐ray spectroscopy, thermogravimetric analysis, X‐ray diffraction, and X‐ray photoelectron spectroscopy). Fibroblasts adhere on the surface of the biomaterials (viability assessed using an (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and visualized using a confocal microscope), and a fluorescently labeled drug (Texas‐Red Gentamicin) can be loaded electrochemically and released (µg cm^?2 quantities) in response to the application of an electrical stimulus.     

纤维素与透明质酸、肝素、丝素、甲壳素湿纺复合生物纤维的制备与性能研究

室温下,将再生纤维素与透明质酸(HA)、肝素(Hep)、丝素(SF)、甲壳素(N-ACS)等的复合纤维的纺丝液溶于NaOH溶液中,通过喷丝头(孔径0.1mm)喷入含有40%~43%硫酸铵的10%硫酸溶液中,得到产率为75%~98%的新型白色、柔韧性较好的复合生物纤维。FT-IR结果显示,复合纤维组分间存在物理吸附和氢键相互作用;少量的HA、Hep、SF和N-ACS等纤维的添加可增加复合纤维的韧能,其中纤维素-SF复合纤维在SF含量为10%时纤度为9.9旦,韧度值为1.08g/旦,伸长率为35.0%,机械性能相对最好。SEM图像中可以看出复合纤维表面呈现条纹、鳞状、填充和均匀包覆的结构,复合纤维间存在一定的相容性;复合纤维直径为19~55μm,密度为0.1~0.36旦/μm。     

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.     

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.     

丝素蛋白在离子液体中的溶解特性研究

文章以离子液体为溶剂,研究了丝素蛋白在离子液体中的溶解特性。首先研究了丝素蛋白在不同结构的离子液体1-烯丙基-3-甲基咪唑氯化物（[AMIM]C1）和1-丁基-3_-甲基咪唑氯化物（[BMIM]c1）中的溶解速率和溶解度。结果发现,相同条件下,丝素蛋白在[AMIM]cl中具有较快的溶解速率和较大的溶解度;随温度的升高,溶解速度加快,合适的温度为95～105℃;随着丝素蛋白浓度的增大,相同条件下丝素蛋白在离子液体中的溶解速度减慢。XRD结果表明,丝素蛋白的非晶相部分首先被溶解,晶相部分结构被破坏后与溶剂作用逐渐被溶解。采用粘度法测定了丝素蛋白分子质量随溶解时间和温度的变化,结果表明：随加热时间增加和温度升高,蛋白质分子质量减小。为保证丝素蛋白的稳定性和溶解速率,温度一般控制在100℃以下,溶解时间小于5h。     

丝素蛋白/聚丙烯酸共混膜仿生合成羟基磷灰石

将丝素蛋白(SF)与聚丙烯酸(PAA)共混,制备丝素蛋白/聚丙烯酸(SF/PAA)共混膜;然后将此共混膜进行改性及矿化处理后,放置于(37±0.5)℃人体仿生液中24h,诱导合成丝素蛋白/羟基磷灰石(SF/HA)复合材料.利用傅里叶红外(FTIR)、X-射线衍射(XRD)、环境扫描电镜(ESEM)以及X射线能谱(EDX...     

Reactive dyeing of silk using commercial acid dyes based on a three‐component Mannich‐type reaction

Acid dyes are employed for commercially dyeing silk, which results in ionic bonds between the silk fibroin and the dye. This generally leads to low wet fastness properties for dyed silk fabrics. In this work, three commercial acid dyes with aromatic primary amine structures were selected to dye silk using a Mannich‐type reaction, resulting in improved wet fastness of dyed silk by forming covalent bonds between silk fibroin and dye. The Mannich‐type reactive dyeing was applied to silk fabrics at both 30 and 90°C in trials. Dyeing at 90°C can shorten the dyeing time compared with dyeing at 30°C, even although dye exhaustion and relative fixation at 90°C were a little lower. The dyeing process was optimised when the dyeing temperature was 90°C, dyebath pH 4, dye‐to‐formaldehyde ratio 1:30 and holding dyeing time 60 minutes. The results showed that the dye exhaustion on silk fabrics for the three aromatic primary amine‐containing acid dyes exceeded 94% and their relative fixation was over 80%. Their washing and rubbing fastness reached grade 4 or higher. Hence, the colour fastness properties of dyed silk fabrics using the Mannich‐type reactive dyeing method is superior to the conventional acid dyeing method using the same aromatic primary amine‐containing acid dyes. The Mannich‐type reactive dyeing for silk fabrics at 90°C can be developed into a novel and rapid reactive dyeing method, promising an effective dyeing process with excellent colour fastness.