Silk proteins for biomedical applications: Bioengineering perspectives

Biomaterials of either natural or synthetic origin are used to fabricate implantable devices, as carriers for bioactive molecules or as substrates to facilitate tissue regeneration. For the design of medical devices it is fundamental to use materials characterized by non-immunogenicity, biocompatibility, slow and/or controllable biodegradability, non-toxicity, and structural integrity. The success of biomaterial-derived biodevices tends to be based on the biomimetic architecture of the materials. Recently, proteins from natural precursors that are essentially structural and functional polymers, have gained popularity as biomaterials. The silks produced by silkworms or spiders are of particular interest as versatile protein polymers. These form the basis for diverse biomedical applications that exploit their unique biochemical nature, biocompatibility and high mechanical strength. This review discusses and summarizes the latest advances in the engineering of silk-based biomaterials, focusing specifically on the fabrication of diverse bio-mimetic structures such as films, hydrogels, scaffolds, nanofibers and nanoparticles; their functionalization and potential for biomedical applications.     

Drug Delivery: Bio‐inspired Heterostructured Bead‐on‐String Fibers That Respond to Environmental Wetting (Adv. Funct. Mater. 8/2011)

Inspired by the geometric structure of ecribellate spider capture silk and its spinning characteristics, we propose a one‐step electrohydrodynamic method to fabricate bead‐on‐string heterostructured fibers (BSHFs). By combining electrospinning and electrospraying strategies using a sprayable outer fluid with low viscosity and a spinnable inner fluid with high viscosity in a coaxial jetting process, hydrophilic poly(ethylene glycol) beads are successfully imprinted on a hydrophobic polystyrene string. It is demonstrated that the BSHFs are capable of intelligently responding to environmental change. With a change in relative humidity, the fibers show a segmented swelling and shrinking behavior in the “bead” parts whereas the “string” parts remain the same. The elastic BSHFs with alternating hydrophilic and hydrophobic surface characteristics represent a type of mesoscale analogues that block copolymers and may bring about new properties and applications. Moreover, the combined electrohydrodynamic approach developed herein should open new routes to multifunctional one‐dimensional heterostructured materials.     

丝网波纹规整填料塔设计软件开发

选取适用于丝网波纹规整填料塔的设计计算模型,通过研究分析大量资料提出了新的规整填料塔负荷性能图的绘制方法,并编写了SPSDS计算源程序,实现了负荷性能图的自动绘制和输出。考核验证了本软件的准确合理。     

Parametric Regionalism

Philip Yuan , Founding Director of Shanghai-based firm Archi-Union Architects, applies parametric techniques to his design and research in China. Here he explains how Parametricism can provide a highly adaptive and open approach to architectural knowledge and spatial organisation, accommodating regional variations in culture and environment, through an emphasis on local climate, materials and craft traditions.     

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.     

“Silk Thread Martyrs”: Palestinian Embroidery

Abstract

Having been introduced to OmarJoseph when a piece of his fashion collection was being considered for inclusion in the British Museum's collection, this interview about his further reflections on that exhibition, Palestinian embroidery techniques, and his subsequent debates about this embroidery in the contemporary context, was undertaken in London.     

ZMD—202型真丝针织平幅溢流练染机的结构与特性

针对目前厚重真丝织物的练染问题，介绍了“ＺＭＤ－２０２型真丝针织平幅溢流练染机”，分析了其主要结构特点、电控系统、工艺技术和特性，并给出了相应的技术规格和指标。     

Discussion on the determination of sail residue in silk fibroin solution with a water quality testing pen北大核心CSCD

the salt residue is one of the quality indexes of silk fibroin products.The products with low salt residue are not only healthier for human body, hut also more stable in exterior qualities, such as color and smell.Instrumental analysis and chemical analysis are currently methods to accurately determine salt residues in silk fibroin products, but they still need to be supplemented by real-time and quick detection methods in practical production.This paper discusses the determination method with a water quality testing pen and investigates the response of the water quality pen to the changes in the concentration of a variety of solutions, and associates with application examples.The results show that the TDS measured by the water quality pen is highly linearly correlated with the changes in the concentrations of CaCU , NaCl, and fibroin-CaCU solutions.The principle and method of the TDS water quality testing pen have an application prospect in the field of real-time and rapid approximate evaluation of salt residue in silk fibroin solution. © 2021 China Silk Association. All rights reserved.     

Genipin-cross-linked silk fibroin microspheres prepared by the simple water-in-oil emulsion solvent diffusion method

This work describes for the first time the preparation of cross-linked and non-cross-linked silk fibroin (SF) microspheres using the simple water-in-oil emulsion solvent diffusion method. Aqueous SF solution and ethyl acetate were used as water and oil phases, respectively. Span80, oil-soluble emulsifier was found to induce the formation of SF microparticles that are completely spherical in shape and smooth in surface. SF microsphere sizes were found to depend upon various process parameters. The SF microsphere matrices showed predominantly random coil conformation. It was possible to fabricate genipin-cross-linked SF microspheres by cross-linking SF solution with genipin before microsphere formation. Both non-cross-linked and genipin-cross-linked SF microspheres contained porous structures. Percentage of dissolution in water decreased and density values of the SF microspheres increased when increasing the genipin ratio and cross-linking time. The genipin cross-linking induced SF conformational transition from random coil to β-sheet form but the size and shape of the SF microparticles did not change. It is suggested that these SF microspheres might be suitable microcarriers for hydrophilic drug delivery.     

肌理在丝绸手绘中的艺术表现

以丝绸手绘肌理为研究对象,通过对肌理本体特性的研究和丝绸手绘技法的总结,将丝绸手绘的肌理艺术表现方法分为直接手绘、防染手绘、印绘结合、助剂染绘多种绘法综合运用等。结合相关的实例,对肌理应用于丝绸手绘的艺术表现手法进行探索,拓宽了丝绸手绘的设计空间。对丝绸手绘肌理的研究与探讨,不仅可以增加丝绸手绘的艺术魅力,给丝绸产品的创新提供了一些新思路。