丝素蛋白对胶原膜性能改善的研究

天然高分子由于其良好的生物相容性而受到广泛的关注。本研究用酶法自制了具有一定水溶性的猪皮胶原。尝试利用丝素和胶原蛋白各自的优点。用简单的溶液浇铸法制备了胶原-丝素共混膜。并通过FTIR、TGA、SEM等手段对其结构进行了表征。结果表明。由于共混膜中俩组份间存在的分子间作用力，加入小于50％的丝素的胶原膜经乙醇处理后与纯胶原膜相比。其力学性能及热稳定性有所的改善。通过改变丝素比例可以调整共混膜的吸水性。由于两组分良好的生物相容性，预料该共混膜可用作生物材料。     

多糖类天然高分子/PVA可生物降解共混膜的研究进展

目的综述天然高分子(淀粉、羧甲基纤维素、壳聚糖、海藻酸钠和木质素)与聚乙烯醇(PVA)复合制备可生物降解共混膜的方法及性能的研究进展。方法分类讨论淀粉、羧甲基纤维素、壳聚糖、海藻酸钠、木质素分别与PVA进行共混制备共混膜的方法及应用。结果总结了多糖类天然高分子/PVA共混膜的研究与应用进展,并指出了该类共混膜今后发展的方向。结论多糖类天然高分子/PVA可生物降解共混膜的研究是目前科研的热点之一,该共混膜对降低环境污染和节约能源具有重要的意义,具有广阔的应用前景。     

丝素-壳聚糖共混膜的制备及其金属离子渗透行为的研究

采用壳聚糖(CS)对天然高分子丝素(SB)进行改性,制备了丝素-壳聚糖(SB-CS)共混膜.FTIR、TGA、SEM的分析表明,该共混膜中SB和CS具有良好的相容性,壳聚糖改善了丝素膜的吸水性和机械性能.通过渗透实验发现不同的金属离子在共混膜中的渗透速率有很大的差异,一些常见的金属离子渗透速率的大小顺序为:K+>Ca2+>Cd2+>Pb2+>Cu2+>Ni2+.     

两亲高分子对超微滤膜的高性能化改性及应用

为提高分子超微滤膜材料的亲水性、抗污染性能、通量和寿命,降低膜材料制造成本,提出两亲高分子共混改性聚偏氟乙烯、聚氯乙烯、聚醚砜膜材料的基础与应用技术研究。研究中,从分子结构设计出发,采用多种活性聚合法合成了一系列具有不同组成和序列结构的两亲高分子,研究了不同组成与序列结构的两亲高分子在成膜过程中的表面富集的规律、两亲高分子在共混膜中的稳定化机制等基础问题;从成膜热力学和动力学出发实现了共混膜多层次微结构的调控,开发出多种两亲高分子合成及其共混超滤膜制备的技术,实现了膜材料规模化生产及其在自来水净化、废水处理及医疗过滤等领域的应用。     

丝素粉体与医用聚氨酯溶胶共混-热压共混膜的制备及性能

采用溶胶共混-热压法成功制备出一系列丝素粉体/聚氨酯共混膜。利用扫描电子显微镜、红外光谱、X射线衍射、动态力学分析和拉伸实验对共混膜的形貌、结构和性能进行了表征,详细研究了丝素含量对共混膜形貌、结构及性能的影响。结果表明,聚氨酯和丝素粉体间存在一定的氢键相互作用,丝素小颗粒均匀分散在聚氨酯中,形成结构较致密的共混膜。溶...     

纤维素基可生物降解共混高分子材料的制备和性能

综述了近年来以纤维素为共混组分制备可生物降解高分子材料的研究进展,重点介绍了纤维素或纤维素衍生物与其它天然高分子(壳聚糖、蛋白质、淀粉等)以及可降解合成高分子(聚乙二醇、聚己内酯、聚乳酸等)共混材料的制备和性能,揭示了纤维素基可生物降解材料在某些应用领域替代石油基材料的潜力.     

壳聚糖与水溶性高分子相容性的研究进展

综述了壳聚糖与水溶性合成高分子和天然高分子相容性的研究进展。从研究方法上,壳聚糖／水溶性高分子的相容性可以采用仪器分析法进行研究,如热分析、光谱分析,力学性能测试和电镜观察等;也可以采用粘度法对相容性进行研究。研究结论都表明,壳聚糖与常见的水溶性高分子,如聚乙烯基吡硌炕酮、聚乙二醇、乙基纤维素和丝蛋白等都存在着部分相容性。相容性的好坏决定了共混物的凝聚态结构,并深刻影响共混物的性能和使用价值。     

高分子分离膜材料及其研究进展

膜材料是膜研究的主要内容,从理论与应用两个角度对高分子分离膜材料进行阐述,先从分离膜的分离机制、分离性能及类别展开介绍,总结各类常见的高分子分离膜材料的性能特点及适用性,针对近年来高分子分离膜材料的合成和制备、改性与应用等研究成果进行概述,通过分析并总结分离膜材料的结构与性能之间的关系,对未来开发新型高分子分离膜材料作出展望。     

走向21世纪的高分子材料

从国家经济战略布署，技术选择出发，在高分子材料领域比热门的课题里，选择性地对高分子合金及共混物，高分子膜，等离子体聚合物，抗蚀剂和液晶聚合物等的较新进展，以及市场情况作一些扼要的评述。     

高分子共混物增容用反应性高分子

多相高分子共混物的研究已成为开发新型高性能高分子材料的重要途径之一。然而，简单的高分子共混物通常具有较低的力学性能和不稳定的形态，因此，高分子共混物的增容是很必要的。传统的增容方法是加入嵌段或接枝共聚物作为增容剂，然而，共混过程中通过反应性高分子就地形成增容剂的方法越来越受到重视。本文综述了用于高分子共混物增容的反应性高分子的类型、制备方法、应用体系及共混过程中所进行的化学反应。用于高分子共混物增     

Controlled release of heparin from blended polyurethane and silk fibroin film

Polyurethane was blended with silk fibroin and heparin to prepare a heparin-releasing system. The release rate and the percentage of the cumulative amount of the released heparin can be controlled by the loading amount of heparin in the film, the composition ratio of silk fibroin to polyurethane, and the thickness of the film. The slower and more sustained release of heparin can be obtained by increasing the film thickness, the loading amount of heparin and the content of silk fibroin in the film. Thus the high bioactivity and long lasting antithrombogenicity of the raw heparin can be maintained for the blended film. The coagulation time tests showed that the composite film had good blood compatibility.     

Stem cell response to multiwalled carbon nanotube-incorporated regenerated silk fibroin films

Multiwalled carbon nanotubes (MWCNTs) are considered to be the ideal reinforcements for biorelated applications on account of their remarkable structural, mechanical and thermal properties. However, before MWCNTs can be incorporated into new and existing biomedical devices, their toxicity and biocompatibility need to be investigated thoroughly. In this study, regenerated silk fibroin/MWCNT nanocomposite films were prepared using a solvent system with pre-dispersed MWCNTs. Their biocompatibility was examined in vitro using human bone marrow stem cells. Scanning electron microscopy and a WST-1 assay demonstrated that the silk fibroin/MWCN film supported BMSC attachment and growth over 7 days in culture similar to the silk fibroin only film.     

A versatile click-grafting approach to surface modification of silk fibroin films

Silk fibroin is a biocompatible, mechanically robust protein polymer that can be made optically transparent, and is widely used and studied as biomaterial for different applications. Its chemical modification is a fascinating way for tuning the properties and widening its application field. Herein, PEG grafting on the surface of regenerated silk fibroin films is obtained by direct linking based on a click reaction between the azido activated silk surface and an alkyne terminated PEG. The so obtained PEGylated films exhibit modified surface properties in comparison with the unmodified films. Through the same click approach, we also show that arrays of ordered fluorescent spots are steadily printed onto the film surface. This expands the versatility of our silk modification to different molecules and polymers, hence allowing for the realization of new functional hybrid materials.     

Flexible bio-composites based on silks and celluloses

Biomaterials have attracted worldwide attention due to the concerns regarding health and the environment. Silk, a natural protein produced by several species of insects, has been examined as a potential material for applications in many biotechnological and biomedical fields. However, regenerated silk fibroin has poor ductility and mechanical properties. Therefore, in this study, silk fibroin-cellulose composite films were prepared in an aqueous system to increase the ductility of regenerated silk fibroin. The morphology of the silk fibroin-cellulose composite film was observed by field emission scanning electron microscopy. The structure of the silk fibroin-cellulose composite films was examined by Fourier transform-infrared spectroscopy. The flexibility was analyzed using a bending test.     

Bovine pericardium coated with biopolymeric films as an alternative to prevent calcification: In vitro calcification and cytotoxicity results

Bovine pericardium, for cardiac valve fabrication, was coated with either chitosan or silk fibroin film. In vitro calcification tests of coated and non coated bovine pericardium were performed in simulated body fluid solution in order to investigate potential alternatives to minimize calcification on implanted heart valves. Complementary, morphology was assessed by scanning electron microscopy — SEM; X-ray diffraction (XRD) and infrared spectroscopy (FTIR-ATR) were performed for structural characterization of coatings and biocompatibility of chitosan. Silk fibroin films were assayed by in vitro cytotoxicity and endothelial cell growth tests. Bovine pericardium coated with silk fibroin or chitosan did not present calcification during in vitro calcification tests, indicating that these biopolymeric coatings do not induce bovine pericardium calcification. Chitosan and silk fibroin films were characterized as non cytotoxic and silk fibroin films presented high affinity to endothelial cells. The results indicate that bovine pericardium coated with silk fibroin is a potential candidate for cardiac valve fabrication, since the affinity of silk fibroin to endothelial cells can be explored to induce the tissue endothelization and therefore, increase valve durability by increasing their mechanical resistance and protecting them against calcification.     

Fabrication of a composite vascular scaffold using electrospinning technology

Intermolecular forces and morphology demonstrated that there was an excellent compatibility between silk fibroin and gelatin. The silk fibroin/gelatin composite vascular scaffold (inner diameter 4.5 mm) was prepared successfully by electrospinning. The scaffold was treated with ethanol to enhance the water-resistant ability and biomechanical properties. After ethanol treatment, the scaffold could hardly dissolve in the water, and FTIR showed that the conformation of the treated silk fibroin/gelatin composite vascular scaffold was mainly β-sheets. The electrospun silk fibroin/gelatin vascular scaffold possessed outstanding biomechanical properties. In vitro cell culture and in vivo subcutaneous implantation demonstrated that the electrospun silk fibroin/gelatin vascular scaffold had an appropriate biocompatibility. The results indicated that the electrospun silk fibroin/gelatin composite vascular scaffold could be considered as an ideal candidate for tissue-engineered blood vessel.     

EDC/NHS交联改性再生桑蚕丝素纳米纤维

用静电纺丝技术制备了再生桑蚕丝素纳米纤维,并用1-(3-二甲基氨基丙基)-3-乙基碳化二亚胺(EDC)和N-羟基丁二酰亚胺(NHS)进行交联改性,考察了交联改性前后,桑蚕丝素纳米纤维微观形貌及聚集态结构等的变化,采用扫描电镜(SEM)、X射线衍射(XRD)及红外光谱(FT-IR)等测试方法对纳米纤维进行表征。研究结果表明,经EDC/NHS交联改性后,纤维直径由250 nm增加到320 nm,纤维表面变粗糙,且纤维发生弯曲变形;丝素的结构以Silk II为主,并含有部分无规卷曲或Silk I构象;桑蚕丝纳米纤维的力学性能和亲水性有所提高,且交联改性后的纳米纤维具有良好的细胞相容性。     

丝素蛋白柔性电子器件材料的研究进展

丝素蛋白材料凭借良好的生物相容性、可控生物降解性、再生形貌多样性等已被制成柔性电子器件在电子领域进行了应用研究.本文首先综述不同溶解方法对蚕丝再生材料制备的影响,同时对丝素蛋白材料的(微球、膜、纤维、凝胶、支架等)制备方法、材料性能进行分析,最后总结了近年来丝素蛋白基柔性电子材料的应用研究进展.尽管已有研究表明可获得各...     

丝素蛋白作为生物医用材料的研究

报道了以下研究,研制成同菌药物的丝素膜,它用于创面保护,能防止感染,加速面愈合;研制成多孔丝素膜,并研究了它们的结构和性能,多孔丝素膜能用作细胞培养的支架,药物缓释剂等;设计和研制成丝素成膜设备,该设备能用以生产丝素创面保护膜及其他医用膜。     

A quicker degradation rate is yielded by a novel kind of transgenic silk fibroin consisting of shortened silk fibroin heavy chains fused with matrix metalloproteinase cleavage sites

Degradation performance of silk fibroin is an important property for its medical applications. Herein we constructed a shortened silk fibroin heavy chain protein fused with a matrix metalloproteinase cleavage site (SSFH-MMP) along with a glutathione S-transferase tag ahead. The digestion assay shows it can be cut by matrix metalloproteinase-2 (MMP-2) at its MMP cleavage site. Furthermore, we introduced the SSFH-MMP into silk fibroin by genetic modification of silkworms in order to increase the degradation rate of the silk fibroin. After acquisition of a race of transgenic silkworms with the coding sequence of the MMP cleavage site in their genomic DNA, we tested some properties of their silk fibroin designated TSF-MMP. The results show that the TSF-MMP has MMP cleavage sites and yields a quicker degradation rate during dilution in MMP-2 enzyme buffer or implantation into tumor tissues compared with that of normal silk fibroin. Moreover, the TSF-MMP is in vitro non-toxic to human bone marrow mesenchymal stem cells (hBM-MSCs) indicating that the TSF-MMP may become a biomaterial with a quicker degradation rate for its medical applications.