丝素改性胶原膜的肝素化及其体外抗凝血性能评价

以1-(3-二甲氨基丙基)-3-乙基碳二亚胺(简称EDCI)为缩合剂对丝素改性胶原膜进行了肝素固定化,测定并研究了固定化肝素的稳定性,应用X光电子能谱分析了材料的表面性质。以凝血酶原时间(PT)、部分凝血活酶时间(APTT)、凝血酶时间(TT)等3个体外凝血时间为评价标准,考察了材料的抗凝血性能。结果表明,肝素化后的丝素改性胶原膜具有良好的抗凝血性。     

丝素抗凝血材料的研究进展

综述了丝素材料在抗凝血方面的研究进展,主要从材料表面肝素化、硫酸化、低温等离子体接枝改性、材料表面内皮化或者几种方法协同作用等展开,对比评述了其优缺点,阐述了对丝素材料表面进行抗凝血改性的研究进展.     

丝素蛋白膜上vWf抗体的固定化及其体外抗凝血性能

用凝血因子的抗体对生物材料进行表面改性以提高其抗凝血性能。以丝素蛋白膜为基质，利用等离子体处理辅助的共价交联方法对vWf因子（von Wilebrand factor)抗体进行了固定化。用酶联免疫法和抗体过剩法对固定化效果进行了评价，固定化抗体的活性采用体外凝血时间（APPT，TT和PT）测定进行检测。结果显示，通过这种方法可以有效地将vWf抗体固定化，丝素蛋白膜固定化vWf抗体后，其抗凝血性能有了一定的改善。本研究结果拓宽了抗体固定化技术的应用范围，同时为抗凝血材料的设计提供了一种新的思路。     

抗凝血丝素蛋白材料的研究进展

综述了作为抗凝血材料的丝素蛋白的改性方法,重点讨论了用s-羧甲基还原角蛋白、硫酸、二氧化硫和vWf(Von Willebrand fator)因子的抗体等对丝素蛋白的改性,并分析了改性材料的抗凝血机理和抗凝血性能.     

肝素化/类肝素化高分子膜材料的研究进展

一般的高分子材料与血液接触时,在材料表面会形成血栓,无法满足抗凝血的要求。将肝素或类肝素物质通过适当的方法固定在高分子材料上,可以提高材料的抗凝血性能。对改善高分子材料血液相容性的方法进行了总结,叙述了肝素化/类肝素化高分子膜材料的特征与优势,重点介绍了肝素化/类肝素化抗凝血高分子膜材料的制备方法研究进展,并对类肝素化高分子膜材料的发展方向进行了展望。     

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。     

肝素化聚醚砜抗凝血材料的研究

进行了聚醚砜表面共价键合肝素的研究,定性定量检测了改性材料中的肝素,并探讨其力学性能和体外凝血时间,结果表明:肝素共价键合到了聚醚砜表面,表面肝素化改性后的聚醚砜材料基本保持了聚醚砜的力学性能,同时抗凝血性能大大提高。     

丝素蛋白膜表面的等离子体磺酸化及体外抗凝血性能

从蚕丝中提取的丝素蛋白（Silk fibroin）制备成薄膜,首次采用二氧化硫等离子体处理在材料表现引入了磺酸基因;同时丝素蛋白膜用氨气等离子体处理后在表面接入氨基,利用1,3－丙磺酸内酯与氨基的反应在材料表面接枝磺酸。采用X光电子能谱和全反射红光谱分析材料的表面性质。材料的体外抗弟血性能由外凝血时间;凝血酶原时间（PT）、部分凝血活酶时间（APTT）和凝血酶时间（TT）作为评价标准。结果表明两种处理方法均能在丝素蛋白膜表面有效地接枝磺酸基因,而且材料的抗凝血性能有显著提高。     

全身肝素化聚醚砜抗凝血生物材料的研究

对聚醚砜材料进行了全面共价键合肝素的研究,并以表面肝素化聚醚砜材料对照,定性定量检测了改性后新材料中的肝素,并探讨其力学性能和体外凝血时间,结果表明:肝素与聚醚砜以共价键结合在一起,全身肝素化改性后的聚醚砜材料基本保持了聚醚砜的力学性能,同时抗凝血性能大大提高,更适用于医疗器械领域,特别是微型化医疗器械领域.     

聚合物的肝素化

本文对肝素的结构和性能，肝素化聚合物的研究进展，以及肝素化聚合物的表征和抗凝血性能的测定进行了扼要综述。     

丝素改性胶原膜的低温等离子体改性及体外抗凝血性研究

选用SO2、NH3、CO2三种工作气体，采用低温等离子体技术对丝素改性胶原膜进行了表面改性。运用X光电子能谱分析了材料的表面性质。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，SO2、CO2等离子体处理可分别在材料表面引入磺酸和酸酸基团，材料的体外抗凝血性得到很大的改善。NH3等离子体处理可以增加材料表面的氨基的数目，它对材料的抗凝血性没有贡献。     

再生丝素/丝胶共混蛋白水溶液的静电纺丝

采用静电纺丝方法制备了再生丝素/丝胶共混纤维,分析了共混配比对再生丝素/丝胶水溶液流变性能和静电纺可纺性的影响,通过扫描电镜、拉曼光谱和DSC等手段研究了所得纤维的形态和微细结构及其力学性能。研究结果表明:随着溶液中丝胶含量的增加,体系的表观粘度增大,静电纺纤维的直径减小且直径分布变窄;并且丝胶的存在有利于丝素蛋白从无规卷曲或α-螺旋结构向β-折叠结构转变,由此可提高静电纺纤维的力学性能。     

Preparation and cytocompatibility of silk fibroin / chitosan scaffolds

One challenge in soft tissue engineering is to find an applicable scaffold, not only having suitable mechanical properties, porous structures, and biodegradable properties, but also being abundant in active groups and having good biocompatibility. In this study, a three-dimensional silk fibroin/chitosan (SFCS) scaffold was successfully prepared with interconnected porous structure, excellent hydrophilicity, and proper mechanical properties. Compared with polylactic glycolic acid (PLGA) scaffold, the SFCS scaffold further facilitated the growth of HepG2 cells (human hepatoma cell line). Keeping the good cytocompatibility and combining the advantages of both fibroin and chitosan, the SFCS scaffold should be a prominent candidate for soft tissue engineering, for example, liver.     

Preparation and cytocompatibility of silk fibroin/chitosan scaffolds

One challenge in soft tissue engineering is to find an applicable scaffold, not only having suitable mechanical properties, porous structures, and biodegradable properties, but also being abundant in active groups and having good biocompatibility. In this study, a three-dimensional silk fibroin/chitosan (SFCS) scaffold was successfully prepared with interconnected porous structure, excellent hydrophilicity, and proper mechanical properties. Compared with polylactic glycolic acid (PLGA) scaffold, the SFCS scaffold further facilitated the growth of HepG2 cells (human hepatoma cell line). Keeping the good cytocompatibility and combining the advantages of both fibroin and chitosan, the SFCS scaffold should be a prominent candidate for soft tissue engineering, for example, liver.     

Silk fibroin membranes from solvent-crystallized silk fibroin/gelatin blends: Effects of blend and solvent composition

Protein membranes have been prepared by mixing gelatin (G) with Bombyx mori silk fibroin (SF) and using aqueous methanol (MeOH) to induce SF crystallization. Amorphous blends of these polymers appear quasi-homogeneous, as discerned from visual observation, electron microscopy and Fourier-transform infrared (FTIR) spectroscopy. Upon subsequent exposure to aqueous MeOH, SF undergoes a conformational change from random-coil to β-sheet. This transformation occurs in pure SF, as well as in each of the G/SF blends, as discerned from FTIR spectroscopy and thermal calorimetry. The influence of MeOH-induced SF crystallization on structure and property development has been measured as functions of blend and solvent composition. By preserving a support scaffold above the G helix-to-coil transition temperature, the formation of crystalline SF networks in G/SF blends can be used to stabilize G-based hydrogels or generate SF membranes for biomaterial, pharmaceutical and gas-separation purposes. The present study not only examines the properties of G/SF blends before and after SF crystallization, but also establishes the foundation for future research into thermally-responsive G/SF bioconjugates.     

丝素蛋白/羟基磷灰石复合材料的制备及性能表征

为了改善羟基磷灰石( HAP) 的脆性和新骨诱导性, 采用共沉淀法合成HAP , 盐溶法制备丝素蛋白(SF) , 在胶体状态下将HAP 和SF 复合得到了SF/ HAP 复合材料。采用扫描电镜(SEM) 、X 射线衍射(XRD) ,傅立叶红外光谱( FIR) 对复合材料结构和化学组成进行了分析, 在模拟体液中检验了复合材料的生物活性, 并对其抗压强度进行了测定。结果表明: HAP 与SF 在纳米尺度进行了复合, 复合材料中SF 主要以β-折叠构象存在,酰胺Ⅴ红外特征峰消失,β-折叠构象的其他峰发生了移动, 表明HAP 与SF 间存在化学结合; 模拟体液中浸泡18 天后, 复合材料表面形成了片层状的HAP ; 与纯的HAP 晶体比较, 复合材料结构稳定, 具有较好生物活性和骨诱导性, 其抗压强度可达63 MPa , 可望成为理想的骨组织替换和工程支架材料。      

Improvements of anticoagulant activities of silk fibroin films with fucoidan

Fucoidan (FC), an effective anticoagulant constituent extracted from brown algae, was introduced into silk fibroin (SF) for improving its blood compatibility. The SF and SF/FC blend films were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and dynamic contact angle determinator (CA). The in vitro anticoagulant activities of the films were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) measurements. The endothelial cell attachment and proliferation viability on the film were assessed by micropipette aspiration technique and MTT assay, respectively. The testing results indicated that the introduction of FC increased the roughness, hydrophilicity and sulfate component of the film surface without impeding the formation of β-sheet conformation in SF. More important, FC brought excellent anticoagulant activity and better endothelial cell affinity to SF. The SF/FC blend film was hopeful to be used as blood-contacting biomaterials.     

Improvements of anticoagulant activities of silk fibroin films with fucoidan

Fucoidan (FC), an effective anticoagulant constituent extracted from brown algae, was introduced into silk fibroin (SF) for improving its blood compatibility. The SF and SF/FC blend films were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and dynamic contact angle determinator (CA). The in vitro anticoagulant activities of the films were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) measurements. The endothelial cell attachment and proliferation viability on the film were assessed by micropipette aspiration technique and MTT assay, respectively. The testing results indicated that the introduction of FC increased the roughness, hydrophilicity and sulfate component of the film surface without impeding the formation of ?-sheet conformation in SF. More important, FC brought excellent anticoagulant activity and better endothelial cell affinity to SF. The SF/FC blend film was hopeful to be used as blood-contacting biomaterials.     

化学交联改性丝素蛋白/海藻酸钠纤维的制备与性能

利用聚乙二醇二缩水甘油醚(PEGDE)化学交联丝素蛋白(SF)、以CaCl_2交联海藻酸钠(SA),采用分步交联的方法制备了SF/SA双网络型复合纤维,通过DV-C型数显黏度计、FTIR、XRD、电子单纤维强力仪、核磁共振变温弛豫分析仪、SEM等对纺丝溶液表观黏度和交联改性SF/SA复合纤维的结构性能进行了表征,研究了交联剂PEGDE添加量对纺丝溶液的表观黏度和交联改性SF/SA复合纤维的力学性能、交联度、微观形貌、吸湿性能和保湿性能等的影响。结果表明,随着PEGDE含量的增加,纺丝溶液的表观黏度呈先下降后增加的趋势,加入适量的交联剂可以降低纺丝溶液的表观黏度,增加纤维的可纺性;纤维的断裂强度、断裂伸长率和交联度呈先增加后减少的趋势,PEGDE与SF的质量比为3∶1时,交联改性SF/SA复合纤维的断裂强度和交联度达到最大值,分别为2.34cN/dTex和55.38%;交联改性SF/SA复合纤维的交联度越大,纤维表面沟槽结构越密集,纤维内部结构越紧密均匀,SF与SA的相容性越好;交联改性后,SF/SA复合纤维吸湿性能和保湿性能得到提高,吸湿平衡时间提前。