同轴静电纺再生丝素/丝胶蛋白纤维的制备及其形态结构表征

模仿蚕丝的组成和结构,利用同轴静电纺丝法制备了以再生丝素蛋白（RSF）为＂芯＂、丝胶蛋白（SS）为＂皮＂的双组分静电纺纤维。通过扫描电镜和透射电镜研究了内层纺丝液流速（Qc）、电压（U）、接收距离（D）以及场强（E）等参数对同轴静电纺RSF/SS纤维形态结构的影响。研究结果表明纤维的平均直径在1400～2100nm左右,皮-芯层结构清晰;Qc对纤维皮-芯层结构的影响较大,过大的内层纺丝液流速会因外层丝胶对内层丝素的包裹不均匀而导致偏芯现象;随E的增加（U增加或D减小）,纤维的直径及其分布显著减小,皮-芯层结构清晰;相同E下,高电压、长距离利于纤维的细化,使直径变细且分布均匀,皮-芯层结构明显。     

Fabrication of novel biofibers by coating silk fibroin with chitosan impregnated with silver nanoparticles

Nanoparticle based agents often applied as coatings on biomaterials have shown promise in delivering the improved sterility against variety of microbes. In the present study, silk fibers (SF) were coated with chitosan impregnated with silver nanoparticles (Ag–C–SF). These Ag–C–SF fibers were characterized using scanning electron microscopy (SEM) with energy dispersive X-ray analysis, atomic force microscopy (AFM), Infra Red spectroscopy, Thermogravimetric Analysis and Microbiological assay techniques. AFM studies have confirmed the nano sized silver particles in chitosan solution; SEM pictures have exhibited the coating of chitosan along with silver nanoparticles on the silk fibroin. The modified fibers have also shown anti-microbial activity and improved thermal stability. The Ag–C–SF fibers may be explored as wound dressing and tendon reconstruction material in future.     

丝胶组分和高湿后处理对静电纺丝素纤维结构与性能的影响

利用静电纺丝法制备了再生丝素和再生丝素/丝胶蛋白纤维,并对所得纤维进行了高湿后处理。采用扫描电镜分析了丝胶蛋白和高湿后处理对静电纺再生丝素蛋白纤维形貌的影响,采用拉曼光谱、X射线衍射和热失重分析研究了所得纤维微细结构及热性能。研究结果表明,添加丝胶蛋白有利于降低静电纺再生丝素蛋白纤维的直径及其分布,而高湿后处理对纤维的形貌没有明显影响;添加丝胶蛋白和/或高湿后处理有利于促进丝素发生向β-折叠构象的转变,并使纤维的结晶结构得到改善,从而进一步提高纤维的热稳定性。     

Fabrication and Fibroblast Attachment Property of Regenerated Silk Fibroin/Tetramethoxysilane Nanofibrous Biocomposites

In this study, regenerated silk fibroin (RSF)/tetramethoxysilane (TMOS) composite electrospun fibers with improved hydrophilicity were successfully prepared by electrospinning method, which was superior for fibroblast attachment. The electrospinning process caused adjacent fibers to “weld” at contact points, as confirmed by scanning electron microscope (SEM) analysis. Fourier transform infrared spectroscopy (FTIR) showed that TMOS has been well incorporated into the silk fibroin electrospun fibers. Thermogravimetric analysis (TGA) was carried out to quantify the water content in RSF/TMOS composite electrospun fibers. The cytotoxicity and L929 adhesion of three‐dimensional RSF/TMOS fibrous biocompoaites were investigated and compared to pure RSF membrane. The water contact angle of RSF/TMOS nanofibrous composites showed a sharp decrease compared to the pure RSF electrospun fibers, which has a great effect on the early stage of cell attachment behavior due to an relatively enhanced hydrophilicity.     

Preparation of regenerated silk sericin/silk fibroin blend microparticles by emulsification–diffusion method for controlled release drug delivery

This study reports drug-loaded silk sericin (SS)/silk fibroin (SF) blend microparticles being fabricated by the water-in-oil emulsion solvent diffusion of a SS/SF aqueous blend solution. Blue dextran was used as the water-soluble drug model. The influence of the SS/SF blend ratio on the characteristics and drug release behavior of the blend microparticles was investigated. The blend microparticles were analyzed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and UV-vis spectroscopy. The blend microparticles were nearly spherical in shape as determined from SEM micrographs. The FTIR and TG results demonstrated that interactions between SS and SF molecules had occurred. The blend microparticles showed very high drug loading efficiency (94–98%) for all blend ratios. The in vitro drug release significantly decreased with decreasing SS blend ratio. The results demonstrated that the SS/SF blend microparticles could be used as biocompatible and biodegradable microparticles for controlled release drug delivery applications.     

Electrospun ultra-fine silk fibroin fibers from aqueous solutions

By using electrospinning technique, beaded, cylinder shaped and ribbon like ultra-fine silk fibroin (SF) fibers were obtained from its concentrated aqueous solution under different processing conditions. These fibers had an average diameter of 700 nm and were characterized by scanning electron microscopy (SEM), Wide-angle X-ray diffraction (WAXD) and Raman spectroscopy. It was found that the morphology and the secondary structure of the as-spun SF fibers were strongly influenced by the solution concentration, as well as the processing voltage. By adjusting these technological parameters, β-sheet conformation and silk II crystal structure of the SF fibers can be formed without any post-treatment.     

以LiBr/C2H5OH/H2O为溶剂的PVA/SF共混体系的相容性

采用LiBr/C2H5OH混合溶剂制备丝素(SF)溶液,与聚乙烯醇(PVA)水溶液进行溶液共混后得到PVA/SF共混膜,采用扫描电镜,差示扫描量热分析,红外光谱,X射线衍射等方法对共混膜进行了形态和结构表征。研究表明,相对于将PVA水溶液与SF水溶液共混得到的共混体系,此方法制备的体系中两组分的相容性得到了一定程度的提高。在SF含量较小的情况下,共混体系中几乎观察不到两相结构的存在。证明在PVA/SF体系中,SF的溶剂选择及SF的含量影响两种组分的相容性。     

静电纺丝法制备金纳米粒子/PVP复合纳米纤维

采用水合肼还原一定浓度氯金酸溶液的方法,在聚乙烯吡咯烷酮(PVP)作保护剂的乙醇/水溶液中,成功制备出粒度较小,且高度分散的金溶胶,紫外吸收光谱证实了溶液中金纳米粒子的存在.采用静电纺丝技术制备了AuNs/PVP复合纳米纤维.采用扫描电镜(SEM)和X射线衍射(XRD)等分析手段对纤维的表面形貌等进行了表征.由扫描电镜...     

三种不同功能蛛丝的超微结构与拉伸力学行为

蜘蛛丝是一种具有优良机械性能的天然动物蛋白纤维,是自然界极具应用潜力的生物材料,但它特有的结构和机械性能与其生物学功能密切相关。为此,本文采用扫描电镜和单纤强力仪对两种结圆网蜘蛛的卵袋框丝和内层丝与圆网铆钉丝三种不同功能蛛丝的超微结构、拉伸力学性能以及断裂能在应力应变曲线的弹性区、屈服区和加强区的分配进行了研究,结果表明不同生物学功能的蛛丝表现出不同的力学行为,并呈现一定的机械性能策略,主要表现为：断裂能在应力应变曲线的弹性区、屈服区和加强区的权衡;不同力学性能参数之间的权衡,如伸长和荷载、断裂强度和延展性等参数之间的权衡,以适应不同的功能要求。这对人们进行新型防护材料的仿生设计具有重要指导意义。     

Green synthesis of gold nanoparticles: Its effect on cocoon and silk traits of mulberry silkworm (Bombyx mori L.)

In the present century the small particles are unique phenomenon which can be developed by bottom-up and top-down processes. These small particles may be considered as nanoparticles which help to build up a technology called nanotechnology. Nanomaterials are those materials which possess the length scales below 100 nm and quite often they make a comparison with a human hair, which is about 80,000 nm wide. We have introduced this technology, specially the green synthesis of gold (Au) nanoparticles in silkworm (Bombyx mori L.). The gold nanoparticles clearly indicate that they have a tremendous effect on enhancement of silk proteins and thus the enhancement of the cocoon weight in silkworms. Gold nanoparticles were prepared from onion, Allium cepa L. The extracted green gold nanomaterials from A. cepa were confirmed by UV-Vis spectrophotometer, XRD, FTIR, SEM, TEM and AFM. The function of green gold nanomaterials extracted from A. cepa was tested on silkworm physiology. We have used UV for judgment of the nature of particles and spectrum peak wavelength showed an absorption peak at 535 nm and indicated the wavelength of the surface plasmon resonance in gold nanoparticles (Au NPs). In blank solutions no such absorption peak was observed at 535 nm. Moreover, the gold (Au) XRD spectrum is supposed to and does demonstrate (111), (200), (220), and (311) peaks in the assortment of superimpose on the background. The process includes the (002) trace graphite peaks, where the (111) peak appears to be exceptionally sharp and strong which helps to propose that it is gold in nature. The FTIR shows that the examined particles are gold in nature. In SEM where electrons interact with atoms in the sample, producing various signals that can be detected and that hold information about the sample's surface topography and composition. The electron beam in SEM is generally scanned in a raster scan pattern, and therefore the beam's position is combined and detects the signal to produce an image. SEM can attain a resolution better than 1 nanometer size. The transmission electron microscope helps to accelerate the electrons as a source of elucidation. The AFM measurement is made in three dimensions process and thus it may be measured as horizontal to X-Y plane. Therefore, decree (magnification) measured at Z–direction, which is normally higher than X-Y. The said repulsive force is major one in AFM. Thus the tip and sample may considered to be the specific force in AFM which may measured at Z–direction. The effect of green gold nanoparticles on mulberry silkworm (Bombyx mori L) can exaggerated the silkworm physiological function. Larvae at 50, 100, 200, and 300 ppm doses were studied right from 1st stage to 5th instar stage. Gold nano treatment resulted in significant alterations in the percentage of fibroin and sericin proteins in the 5th instar as compared to that of control. At a 300 ppm dose of green nano gold the percentage of fibroin was 78.07, while sericin decreased from 39.46 (control) to 21.92. It was observed that the green gold nanomaterials have the ability to not only alter the fibroin protein but also enhance the cocoon and silk traits. The aim of this study was to investigate the effect of extra foliation of mulberry leaves with G-GNPs extracted from A. cepa on larval duration, mature silk gland weight, pupal weight, cocoon weight, cocoon shell weight, fibroin and sericins contents, etc. Moreover, the enhanced production of fibroin will explore a new venture in bioengineering and also in biomedical field.     

再生丝素蛋白水溶液静电纺丝性能的研究

运用静电纺丝方法,从再生蚕丝素蛋白水溶液中制得了念珠状的、圆形的或扁平状的超细再生丝,纤维的直径在100～900nm之间,平均为700nm.溶液浓度和电压强度对静电纺丝性能的影响很大,当纺丝液浓度为28%（质量分数）,电压为20kV,喷射距离为 11cm时,可制得具有光滑表面的圆形再生丝.大角X衍射（WAXD）测试结果认为,静电纺再生丝中含有α螺旋和β-折叠结构,但其结构既不同于无定型丝素膜,也不同于天然蚕丝纤维,介于二者之间.     

纳米羟基磷灰石/丝素蛋白/聚己内酯复合超细纤维的制备及表征

通过静电纺丝法制备出纳米羟基磷灰石/丝素蛋白/聚己内酯复合超细纤维,利用扫描电镜、红外光谱仪、X射线衍射仪对纳米羟基磷灰石/丝素蛋白/聚己内酯复合超细纤维形貌和结构进行表征,并进行了拉伸测试。结果表明,随着超细纤维中羟基磷灰石含量的增加,纤维的直径逐渐降低,纤维中聚己内酯的结晶逐渐变差。相比于丝素蛋白/聚己内酯超细纤维,含有质量比为30%羟基磷灰石的复合超细纤维仍具有较好的力学性能。体外小鼠成纤维细胞(L929)培养表明,纳米羟基磷灰石/丝素蛋白/聚己内酯复合超细纤维对细胞没有毒性。     

Silver nanoparticles incorporated electrospun silk fibers

We present a simple and mass-producible method of incorporating silver nanoparticles on the surface of electrospun silk non-woven membranes for the fabrication of antimicrobial wound dressings. Nanofibrous silk membranes with fiber diameters of 460 +/- 40 nm were electrospun from an aqueous Bombyx mori fibroin solution. The electrospun membranes incorporating silver nanoparticles were prepared by dipping the membranes in aqueous silver nitrate (AgNO3) solution (0.5 or 1.0 wt%) followed by photoreduction. Field emission scanning and transmission electron microscopy showed that silver nanoparticles were generated on the electrospun silk fibroin nanofibers as well as inside them. The interaction between the silver nanoparticles and amide groups in the silk fibroin molecules was characterized using X-ray photoelectron spectroscopy.     

Polyacrylonitrile-based carbonized fibers and metal-carbonized fiber nanocomposites for thermal transport

This work examines the fabrication and thermal analysis of metal-carbon composite fibers prepared via an electrospinning process. The metal-carbon composite fibers of silver, copper, gold, and nickel were prepared by electrospinning of a composite solution of polyacrylonitrile (PAN) and metal precursor followed by heat treatment in air, nitrogen to 1000 degrees C and in 6% H2, respectively. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy dispersive spectroscopy (EDS) and Scanning thermal microscopy (SThM) were applied to characterize the metal-carbon fibers. TEM analysis showed a relatively uniform, contact-free distribution of the nanoparticles on the surface of the carbon fibers with size range of 3 nm-10 nm. Thermal analysis data showed an enhancement in the thermal conductivity of the nanomaterials when compared with the model PAN-based carbonized fibers. This was attributed to the incorporation of metal nanoparticles in the fiber matrix and on the surface.     

再生丝素/聚乙烯醇共混纳米纤维的制备及表征

以三氟乙酸、二氯甲烷和水为溶剂,采用静电纺丝的方法制备再生丝素/聚乙烯醇共混纳米纤维。分析了共混配比对相容性及静电纺丝的影响,采用扫描电镜、X射线衍射仪、红外光谱仪等对所得纤维的形态与结构进行了表征,测试了纳米纤维的力学性能,结果表明:丝素分子和聚乙烯醇分子间发生了某种程度的相互作用,相容性得到改善,添加聚乙烯醇的丝素纳米纤维的力学性能有明显改善。     

柞蚕丝素水溶液静电纺纳米纤维的制备

柞蚕丝素具有优良的生物相容性、低的生物免疫反应、细胞亲和性等特性,是一种性能优越的潜在生物医学材料。本文以我国特有的柞蚕丝为原料,以水作为溶剂,通过静电纺丝技术制备了柞蚕丝素纳米纤维。并利用SEM、XRD、DSC、核磁共振等测试手段研究了柞蚕丝素水溶液静电纺纳米纤维的形貌、构象、结晶结构等。研究表明:柞蚕丝素水溶液静电纺丝的最佳浓度为29%～31%(w/w)、所得纤维的直径范围在217～717nm之间,构象以无规卷曲和α-螺旋为主,水蒸气处理后,纤维构象由α-螺旋向β-折叠转变。     

Antibacterial activity of hybrid chitosan–cupric oxide nanoparticles on cotton fabric

In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X‐ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle‐containing (hybrid) solutions by sonication method followed by pad‐dry‐cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR‐attenuated total reflectance, and SEM analyses, respectively. The hybrid‐coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO‐coated fabric > CS‐coated fabric.Inspec keywords: cotton fabrics, nanoparticles, antibacterial activity, transmission electron microscopy, Fourier transform spectroscopy, infrared spectroscopy, scanning electron microscopy, copper compoundsOther keywords: antibacterial activity, hybrid chitosan‐cupric oxide nanoparticles, cotton fabric, cupric oxide nanoparticles, sonochemical method, X‐ray diffraction, XRD pattern, Fourier transform infrared spectroscopy, FTIR spectroscopy, scanning electron microscopy, SEM, transmission electron microscopy, TEM methods, colloidal chitosan solution, ultrasound irradiation method, colloidal solution, TEM images, cotton fabrics, nanoparticle‐containing solutions, sonication method, pad‐dry‐cure method, morphological analyses, structural analyses, functional analyses, FTIR‐attenuated total reflectance, SEM analyses, hybrid‐coated cotton fabrics, Staphylococcus aureus, Escherichia coli, bioactivity performance, CuO     

Preparation and characterization of nanostructured copper bismuth diselenide thin films from a chemical route

Thin films of copper bismuth diselenide were prepared by chemical bath deposition technique ontoglass substrate below 60°C. The deposition parameters such as time, temperature of deposition and pH of the solution, were optimized. The set of films having different elemental compositions was prepared by varying Cu/Bi ratio from 0·13–1·74. Studies on structure, composition, morphology, optical absorption and electrical conductivity of the films were carried out and discussed. Characterization includes X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDAX), absorption spectroscopy, and electrical conductivity. The results are discussed and interpreted.     

Electrospinning of reconstituted silk fiber from aqueous silk fibroin solution

Silk nanofibers were successfully prepared by electrospinning an aqueous solution of regenerated silk fibroin (RSF, from Bombyx mori) with higher molecular weight. Many factors, such as concentration, electrical conductivity of the fibroin solution and applied electric field were found to influence the morphology of these nanofibers. The conformation of RSF nanofibers was transformed from random coil/helical to β-sheet after the post treatment with pure ethanol. Under optimal conditions, the as-spun non-woven mats achieved good mechanical properties. The apparent stress and strain at break were 11.1 ± 0.7 MPa and 10.2 ± 1.6%, respectively, which is important for the application of such a unique fibrous protein.     

{H3[PMo12O40]/Pt/PAMAM}复合膜的制备及对甲醇的电催化氧化

采用循环伏安法在玻碳电极上制备了{H3[PMo12O40]/Pt/PAMAM}复合膜,用X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、电子能谱技术(EDS)、原子力显微镜(AFM)和循环伏安法(CV)研究了膜的组成、形貌及其对甲醇的电催化氧化活性。结果表明,Pt纳米粒子在PAMAM基底上分散均匀;最外层沉积H3[PMo12O40]后,与相同条件下制备的Pt/PAMAM膜相比,{H3[PMo12O40]/Pt/PAMAM}复合膜修饰电极对甲醇的氧化有更强的电催化活性。