丝素/丝胶共混膜的制备及其物理性能

以环氧树脂为交联剂 ,制备丝素 丝胶蛋白共混膜 ,探讨了丝素比例、交联剂种类对共混膜性能和结构的影响。指出丝素比例为 10 %左右、以PEGO4 1为交联剂的共混膜 ,其主要物理性能较好。     

丝素/明胶共混膜的结构和性能

采用热风干燥法制备丝素/明胶共混蛋白膜,探讨了共混比例、交联剂对共混膜的性能和结构的影响。共混比例为50/50左右时,膜的断裂伸长率和伸长弹性率都较大。     

丝素/聚氨酯共混膜的性能

将蚕丝丝素水溶液与水性聚氨酯充分混合后，可制得均匀的共混膜。共混膜内聚氨酯能阻止丝素蛋白质的结晶。随着聚氨酯所占比例的提高，丝素／聚氨酯共混膜的力学性能显著改善。     

丝素／聚氨酯共混膜的性能研究

用水性聚氨酯和丝素蛋白共混制膜。测试了不同配比的共混膜的结构及其强度、伸长率、透湿性和在不同介质中的吸水性。共混膜随其中聚氨酯所占比例的增加，强度减小，伸长率提高，吸水性下降。其中丝素／聚氨酯配比为50／50的透湿性最差。     

丝素-聚乳酸共混膜体外降解性研究

通过制备丝素-聚乳酸共混膜,与纯的丝素膜进行比较,研究共混膜的体外降解性能,并得出结论：共混膜的降解性能比纯的丝素膜的降解性能好,从而拓展了共混膜的使用空间。     

丝素蛋白质量分数对羽毛角蛋白共混膜性能的影响

角蛋白、丝素蛋白具有良好的生物降解性,因此在膜材料领域得到了极大的关注。角蛋白与明胶、甘油共混具有较好的成膜性,但其共混膜极易溶于水。为了改善角蛋白共混膜的力学性能和降低膜的热水溶失率,利用丝素蛋白、角蛋白、明胶和甘油制备共混膜。结果表明:丝素蛋白的加入可以提升共混膜的断裂强度,当共混膜中丝素蛋白与角蛋白的混合质量比为1∶1时,共混膜的断裂强度最大;同时,丝素蛋白的加入可以大幅度降低共混膜的热水溶失率,使共混膜在水中可以维持基本形态结构。     

胶原/丝素膜的制备及其SO2等离子体改性研究

利用丝素和胶原蛋白各自的优点,制备了胶原一丝素共混膜,并通过FTIR、TGA、SEM等手段对其结构进行了表征。选用SO2采用低温等离子体技术对胶原／丝素膜进行了表面处理。材料的体外抗凝血性能由体外凝血时间——凝血酶原时间（PT）、部分凝血活酶时间（APTT）、凝血酶时间（TT）作为评价标准。结果表明,共混膜中二组分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改善。通过改变丝素比例可以调整共混膜的吸水性。经SO2处理后由于在共混膜表面引入了磺酸基团,因而具有良好的抗凝血性能。     

多元醇对SF/PVA共混体系的增容作用

比较了丝素／聚乙烯醇和丝素／聚乙烯醇／多元醇共混物的相容性，并对其膜的机械性能进行了测试，结果表明，在无添加剂的条件下聚乙烯醇和丝素不相容，加入一定量的多元醇后其相容性得到改善，促进了力学性能的提高。     

丝素共混膜的研究现状及与聚乳酸的研究初探

丝素膜是一种性能优良，用途广泛的天然高分子生物材料，但纯丝素膜在干燥状态力学性能很差，只有通过与其它高分子化合物共混得到改善，从而拓宽丝素膜的应用范围，文章综述了丝素与高分子化合物形成共混膜的应用现状，以及在此基础上提出了丝素与聚乳酸共混的研究设想。     

聚乙烯醇／丝素蛋白共混膜的结构与性能研究

通过聚乙烯醇（PVA）与丝素（SF）物理共混,制备了PVA／SF共混膜,用SEM,DSC,IR和X－射线分析仪对共混膜的结构进行了表征,测试了的力学性能和透水性,探讨了共混膜用作创面保护膜的可行性。     

硼酸改性丝胶聚乙烯醇膜的性能

将硼酸加入丝胶/聚乙烯醇的共混水溶液中,通过平板膜法制备薄膜材料。研究硼酸对丝胶/聚乙烯醇膜材料的力学性能和耐溶失性能的影响,利用红外光谱分析和差示扫描量热分析研究硼酸对材料的改性机制和热稳定性。结果发现:硼酸的加入提高了材料的抗张强度和耐溶失性,硼酸对丝胶蛋白在膜材料中有明显的固定作用,明显改善了材料的热稳定性;当丝胶与聚乙烯醇物质的量比为3∶7,硼酸用量为丝胶与聚乙烯醇总质量的0.4%时,所制备膜的综合性能相对较好。     

丝胶对棉织物改性的研究

以二氯均三嗪化合物作为交联剂,采用丝胶对棉织物进行改性,探讨了不同丝胶质量浓度对改性棉织物性能的影响。结果表明,棉织物用丝胶改性,能提高其尺寸稳定性、抗皱性、吸湿性,但对白度影响不大。     

柔软丝胶蛋白膜的制备

用聚乙二醇缩水甘油醚作为交联剂制备丝胶蛋白膜,并对丝胶蛋白膜的主要物理性能和结构特征进行了测试和分析.结果表明,聚乙二醇缩水甘油醚对丝胶蛋白具有明显的交联作用.在丝胶水溶液中添加占丝胶质量30%～40%的PEG-DE,采用流延法制得的丝胶蛋白膜具备很好的柔软性和很高的断裂伸长率.PEG-DE引起了膜内的丝胶蛋白结晶形态的变化.     

PLGA/PLA共混纳米纤维膜的结构与性能

 为制备组织工程支架材料,以具有优异生物相容性的PLGA和PLA为原料,通过静电纺丝法制备PLGA/PLA共混纳米纤维膜。通过扫描电镜、流变仪、TG-DSC热分析和电子强力仪测定共混纳米纤维膜的形貌结构、微细结构和力学性能。结果表明：通过静电纺丝法可成功制备PLGA/PLA共混微、纳米级纤维膜。随着PLA共混比例的提高,纺丝液的黏度逐渐提高,使得纳米纤维的直径增大、分布均匀、孔径增大、孔隙率减小;热分析结果表明随着PLA共混比例的增大,支架的结晶度和结构稳定性提高;随着PLA共混比例的增加,支架的断裂强度增加,伸长减小;可通过调节PLGA和PLA的共混比例达到调控支架材料的结构与性能,以满足不同组织工程支架的要求。     

Evaluation of sericin/collagen membranes as prospective wound dressing biomaterial

Sericin, a silk protein, has high potential for use in biomedical applications. In this study, wound dressing membranes of Sericin (S) and Collagen (C) were prepared by glutaraldehyde cross-linking at S/C; 2:1, 1:1, 1:2, and 0:1 weight ratios. They were stable in water for 4 weeks. However, increasing the proportion of sericin had decreasing effect on the membrane stability. Water swelling property of membranes was enhanced with sericin. The highest water swelling was obtained in 1:1 group (9.06 g/g), but increasing collagen or sericin content in the membranes had a diminishing effect. Highest water vapor transmission rate was obtained with 1:2 group (1013.80 g/m²/day). Oxygen permeability results showed that 1:2 (7.67 mg/L) and 2:1 (7.85 mg/L) S/C groups were better than the other groups. While sericin decreased the tensile strength and elongation of membranes, it increased modulus. Sericin also increased brittleness of membranes, but their UTS range (24.93–44.92 MPa) was still suitable for a wound dressing. Membranes were not penetrable to microorganisms. Cytotoxicity studies showed that fibroblasts and keratinocytes attached and gained their characteristic morphologies. They also proliferated on membranes significantly. After 1 week of subcutaneous implantation, a fibrous capsule formed around all membranes with an acute inflammation. Sericin containing membranes showed signs of degradation (at 2nd week), while collagen only membranes remained largely intact. Eventually, sericin containing membranes degraded in 3 weeks with moderate inflammatory response. Overall results suggest that sericin/collagen membranes would be favorable as wound dressing material when sericin ratio is less than or equal to the collagen component.     

丝胶凝胶化机制及其应用的进展

综述了丝胶在凝胶溶液转变过程中的一系列物理性能变化,其中包括凝胶化过程中透光率、表面张力、胶粘强度的变化,说明了温度、溶液浓度、pH值对凝胶化速度的影响。介绍了用X射线衍射、圆二色吸收光谱、红外吸收光谱、DTA等测试方法对引起这些变化的微观机制,说明了丝胶凝胶是一种热可逆性凝胶。同时还介绍了丝胶与几种不同的物质共混或交联所得产物的凝胶特性及其应用。     

亚甲基丁二酸交联变性对淀粉浆料性能的影响

为提升淀粉浆料的使用性能,以亚甲基丁二酸(MSA)为交联剂,采用半干法制备了不同交联度的亚甲基丁二酸交联淀粉(MSACLS)。对其颗粒结构与表观形貌进行了表征分析,考察了MSA交联变性对淀粉浆液黏度热稳定性、黏附性以及对浆膜力学性能与水溶性的影响。结果表明:这种交联变性能够明显提升淀粉浆液的黏度热稳定性及其对涤纶纤维的黏附性,提高浆膜的力学性能,降低浆膜的水溶性;随着交联度的增大,MSACLS浆液的黏度热稳定性、对涤纶纤维的黏附力及其膜的断裂强度逐渐提高,浆膜的断裂伸长率呈现先提高后降低的趋势,水溶性逐渐降低;选择交联度为49.4的MSACLS在涤纶经纱上浆中使用为宜。     

ANTIOXIDANT ACTIVITIES OF SILK SERICIN FROM SILKWORM BOMBYX MORI

This study was conducted to investigate the free-radical-scavenging activity and antioxidant activity of silk sericin. Silk sericin was prepared from silkworm Bombyx mori and its ability to scavenge hydroxyl, superoxide and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was determined by Electron Spin Resonance (ESR) and ultraviolet spectrophotometry, respectively. The antioxidant activities of the silk sericin, including lipid peroxidation in the linoleic acid system, reducing power and ferrous-ion-chelating ability, were evaluated. The results showed that silk sericin had a strong scavenging capacity for hydroxyl, superoxide and DPPH radicals. The results also showed that silk sericin had potent antioxidative activity on the peroxidation of linoleic acid. The reducing power and ferrous-ion-chelating ability of silk sericin were significant. These results indicated that silk sericin from silkworm B. mori was a natural antioxidant with potent antioxidative activity.

PRACTICAL APPLICATIONS

Most of silk sericin must be removed during raw silk production at the reeling mill and other stages of silk processing. At present, silk sericin is mostly discarded in silk processing waste water. If silk sericin is recovered and recycled, it can represent a significant economic and social benefit. Silk sericin is a natural macromolecular protein derived from the silkworm Bombyx mori . Silk sericin is useful because of its antioxidant activity. Silk sericin can be cross linked, copolymerized and blended with other macromolecular materials, especially artificial polymers, to produce materials with improved properties. The protein is also used as an improving reagent or a coating material for natural and artificial fibers, fabrics and articles. The materials modified with silk sericin and sericin composites are useful as degradable biomaterials, biomedical materials and functional membranes.     

Electrospinning and characterization of poly (vinyl alcohol)–sericin nanofibers as a potential for tissue engineering applications

Poly vinyl alcohol (PVA) is a hydrophilic, biocompatible, and biodegradable polymer which has found application in biodrugs and tissue engineering. Sericin accompanying silk is a waste which is produced in scouring silk and has interesting properties which has attracted the attention of researchers. Silk sericin is also hydrophilic, biodegradable, and biocompatible. Moreover, it is cheap and anti-cancerous. Mixture of PVA and sericin in the form of 2D membrane or 3D hydrogels has been employed to heal skin damages. This research aimed at electrospinning PVA–sericin blend nanofibers in the form of a mat which has applications in tissue engineering, using dimethyl sulfoxide (DMSO) as an organic solvent. This research showed that the solution of PVA–sericin in DMSO was electrospinnable; however, the addition of urea to the solution made the electrospinning easier. The electrospinning solution contained ratio of 0:100, 10:90, 15:85, 20:80, and 25:75 sericin (%w/w)–PVA (%w/w). The electrospun PVA–sericin nanofibers had an average diameter in the range of 179–285 nm. X-ray diffractometer and differential scanning calorimetry investigations showed no reaction occurring between PVA and sericin. Polyvinyl alcohol 100% was also electrospun in DMSO. Up to now, the electrospinning of PVA in non-aqueous media has not been reported in the literature.     

大豆蛋白纤维的丝胶改性及其性能研究

用丝胶和阳离子交联剂改性大豆蛋白纤维和织物，对丝胶改性大豆蛋白纤维的工艺条件进行了优化。研究了丝胶改性大豆蛋白纤维的染色性能，同时对染色效果及其他性能如折皱回复角、毛细管效应、白度等指标进行了测试，并与未改性、阳离子单独改性的大豆蛋白纤维进行了比较。结果表明。用丝胶和阳离子交联剂对大豆蛋白纤维改性。织物的性能明显改善。