组织工程用蛋白基水凝胶

水凝胶是在水中溶胀并保持大量水分而又不溶解的聚合物,与生物机体组织很相似.蛋白基水凝胶具有良好的生物相容性和生物降解性,在组织工程中的应用主要是恢复、维持或改善受损机体组织与器官的形态和功能,以达到修复再生的目的,被誉为下一代最具潜力的组织工程用生物材料.综述了组织工程用天然蛋白基和合成蛋白基水凝胶的研究进展,并指出了其优、缺点及发展方向.     

壳聚糖支架在组织工程中的应用

综述了壳聚糖作为细胞生长载体在软骨组织工程，骨组织工程和皮肤组织工程等方面的应用进展，表明壳聚糖有望成为优异的组织工程支架材料。     

组织工程用生物降解材料特性

组织工程的发展，希望生物医用材料能提供仿生微环境，且其生物降解速率和新组织形成速率相适应。本文侧重这些重要问题进行概述。     

组织工程用生物材料与系统

当今以工程科学、生命科学原理开发修复、维持或改善组织功能的生物取代物为目标的组织工程正引起先进国家官、产、学各方面的关注，此高新技术不仅能显著提高对疾患的诊治水平，更能形成组织工程产品市场。本文结合１９９６年在加拿大多伦多举行的第５届世界生物材料大会期间举办的组织工程科学展示会为经纬，介绍相关的研究与开发进展。     

羟基磷灰石/羧甲基壳聚糖组织工程骨的制备及表征

以京尼平(Genipin)为交联剂,通过粒子沥滤结合冷冻干燥工艺制备纳米羟基磷灰石/羧甲基壳聚糖复合支架。然后依据组织工程的原则,将pcDNA3.1-血管内皮生长因子(Vascular endothelial growth factor,VEGF)165质粒转染后的骨髓间充质干细胞(Bone marrow stromal cells,BMSCs)与支架复合构建组织工程骨。最后将该组织工程骨植入到兔桡侧,观察其成骨能力及降解速度。结果表明:京尼平交联的支架材料的微观结构、力学性能与天然松质骨相似,可满足支架材料的要求;且支架材料具有自发荧光特征,便于观察支架的微结构及界面上细胞的粘附情况;动物实验表明所得复合骨具有生物相容性好、无毒副作用的优点及促进局部微血管形成、加快骨缺损修复的作用,其降解速度与骨生长速度基本匹配,是一种潜在的性能优良的骨修复材料。     

组织工程用高分子骨架研究的进展

组织工程是一个新兴的交叉学科。结合目前组织工程用高分子骨架研究和发展的最新状况，探讨了高分子骨架材料的本体结构、性能及表面形态与分子结构要求，并对常用的骨架制备方法进行了概述。     

壳聚糖与羧甲基壳聚糖蛋白质印迹聚合物的制备及吸附性能

首先制备了壳聚糖的衍生物——羧甲基壳聚糖,再以壳聚糖与羧甲基壳聚糖的共混物为功能单体,牛血清白蛋白(BSA)为模板蛋白质,制备了一种壳聚糖与羧甲基壳聚糖共混物的蛋白质印迹聚合物。模板蛋白质吸附测试结果表明,该蛋白质印迹聚合物对BSA的吸附量是非印迹聚合物的30.8倍;对不同蛋白质的吸附测试结果表明,相比于其它对比蛋白质,该蛋白质印迹聚合物具有良好的选择性吸附模板蛋白质BSA的效果;并且该蛋白质印迹聚合物具有良好的可重复使用性能。     

壳聚糖类复合材料应用于骨修复的研究进展

壳聚糖是天然多糖类高分子化合物甲壳素的脱乙酰产物,具有良好的生物相容性、可降解性和生物活性,可作为骨修复材料,并可应用于骨组织工程材料中的三维生长支架,作为种子细胞或活性生长因子的生物载体材料.综述了壳聚糖类复合材料在骨填充修复材料、骨组织工程和软骨组织工程方面应用的状况及前景.     

纳滤纯化低聚壳聚糖制备液

对低聚壳聚糖制备液进行了纳滤纯化研究,试验确定纳滤的最佳操作条件为35～40℃、操作压力为1.0 MPa,制备液在纳滤之前还应稀释2.5倍,间歇恒容渗滤过程的每一运行周期的最优浓缩倍数为1.5倍.在该条件运行下,制备液中的单糖和大部分二糖及一价盐离子被脱出,高活性低聚壳聚糖的纯度高达92％,料液体积浓缩接近2倍.     

壳聚糖与丙交酯接枝共聚物的制备与表征

壳聚糖与聚乳酸是具有良好生物相容性的高分子材料,目前被广泛用于生物医学材料,特别是作为组织工程支架.本文以壳聚糖为原料,经过改性制备6-O-三苯甲基-2-邻苯二甲酰基-壳聚糖,作为大分子引发剂,以辛酸亚锡催化D,L-丙交酯接枝聚合,制备共聚物大分子.采用傅立叶变换红外光谱、核磁共振氢谱、碳谱对其结构进行表征,证实了共聚物的生成.热分析测试表明,共聚物具有不同于聚乳酸的热特性,熔点152.8℃.接触角测试表明共聚物具有较好的亲水性.凝胶色谱测定不同反应物配比对共聚物分子量的影响.壳聚糖与丙交酯的接枝共聚物具有较聚乳酸及壳聚糖更为优良的性能,可作为组织工程支架材料.     

Preparation and characterization of oxidized alginate covalently cross-linked galactosylated chitosan scaffold for liver tissue engineering

Liver tissue engineering (LTE) requires a perfect extracellular matrix (ECM) for hepatocytes culture to maintain high level of liver-specific functions. Here, we reported a LTE scaffold derived from oxidized alginate covalently cross-linked galactosylated chitosan via Schiff base reaction, without employing any extraneous chemical cross-linking agent. The structure of galactosylated chitosan (GC) and oxidized alginate was confirmed by Fourier transformed infrared (FTIR) spectra, proton nuclear magnetic resonance (¹H-NMR) spectroscopy, X-ray diffraction (XRD) or thermogravimetric (TG) analysis. The structure and properties of a series of the scaffolds were characterized by FTIR, XRD, scanning electron microscopy (SEM), porosity, equilibrium swelling, mechanical properties, thermal stability and in vitro degradation. FTIR spectra confirmed the characteristic peak of Schiff base groups in the scaffolds and XRD indicated the scaffolds could be amorphous. SEM analysis showed that the scaffolds displayed highly porous surfaces with average pore size of 50-150 μm and interconnected pore structure in the internal structure with average pore size of 100-250 μm. Porosity measurement suggested the scaffolds had a porosity of about 70%. The compressive modulus of the scaffolds (hydrated) was in the range of 4.2-6.3 kPa. Further studies showed that, with the increase of the oxidized alginate content, the equilibrium swelling and in vitro degradation rate of the scaffolds decreased and the thermal stability slightly increased, which might mainly attribute to the difference of the degree of cross-linking and the nature properties of the raw materials. Additionally, the biocompatibility of the scaffolds was evaluated in vitro. The results showed that the hepatocytes cultured on the scaffolds had a typical spheroidal morphology, formed multi-cellular aggregates and presented perfect integration with the scaffolds, which suggested that the scaffolds may be potential candidates for LTE strategies.     

海藻酸盐水凝胶在组织工程中的研究

海藻酸盐作为一种天然高分子无毒材料，由于其良好的生物相容性和安全性，受到医学和材料学领域科学家的广泛关注．文章通过对海藻酸盐各项特性的介绍，分析了目前在组织工程应用中所存在的问题，并对海藻酸盐改性方面的研究做了总结。     

原位沉析羟基磷灰石-壳聚糖骨组织工程支架材料的研制

仿生构建羟基磷灰石-壳聚糖复合材料是制备骨组织修复材料的重要途径之一.本研究利用有机官能团对无机物矿化的调控作用,在壳聚糖多孔支架表面原位沉析羟基磷灰石(HAp).在仿生溶液中,采用简单的化学处理,使HAp晶体在壳聚糖多孔支架表面原位沉析.研究结果表明壳聚糖分子结构中的氨基作为成核位点,在碱性条件下首先与吸附Ca2 ,再通过静电作用力吸附仿生溶液中的PO43-、OH-等其它离子促使HAp晶体在壳聚糖支架材料表面的成核、长大.此类材料有望成为一种生物活性的骨组织工程材料.     

Electrospun nanofibers of collagen-chitosan and P(LLA-CL) for tissue engineering

Electrospun nanofibers could be used to mimic the nanofibrous structure of the extracellular matrix (ECM) in native tissue.In tissue engineering,the ECM could be used as tissue engineering scaffold to ...     

Silk fibroin-based scaffolds for tissue engineering

Silk fibroin (SF) from the Bombyx mori silkworm exhibits attractive potential applications as biomechanical materials, due to its unique mechanical and biological properties. This review outlines the structure and properties of SF, including of its biocompatibility and biodegradability. It highlights recent researches on the fabrication of various SF-based composites scaffolds that are promising for tissue engineering applications, and discusses synthetic methods of various SF-based composites scaffolds and valuable approaches for controlling cell behaviors to promote the tissue repair. The function of extracellular matrices and their interaction with cells are also reviewed here.     

Mechano-biology as an optimization principle for biological tissue engineering

Rapid prototyping and direct fabrication has provided researchers and scientist with a wealth of opportunities to fabricate synthetic tissue replacements, so called scaffolds. The goal is to fill critical size defects with such materials and allow the body to slowly degrade them and build de-novo biological tissue on its place. However, for this process to take place the structural organization levels of these synthetic tissue replacements need to follow design criteria that promote cell attachment, cell proliferation, and maintain the cell's differentiated function. The scaffold's architecture defines the ultimate shape of the newly grown tissue. Furthermore, since most scaffolds are needed for tissue repair in load-bearing applications, the mechano-biological component affects tissue growth long after biochemical factors (e.g., growth hormones) or pre-seeded cells are lasting. This article describes current efforts in identifying mechano-biological principle that are believed to guide tissue formation based on biomechanical loading.