摘要：The aim of this study was to fabricate biomatrix/polymer hybrid scaffolds using an electrospinning technique. Then tissue engineered heart valves were engineered by seeding mesenchymal stromal cells （MSCs） onto the scaffolds. The effects of the hybrid scaffolds on the proliferation of seed cells, formation of extracellular matrix and mechanical properties of tissue engineered heart valves were investigated. MSCs were obtained from rats. Porcine aortic heart valves were decellularized, coated with poly（3-hydroxybutyrate-co-4-hydroxybutyrate） using an electrospinning technique, and reseeded and cultured over a time period of 14 days. In control group, the decellularized valve scaffolds were reseeded and cultured over an equivalent time period. Specimens of each group were examined histologically （hematoxylin-eosin [HE] staining, immunohistostaining, and scanning electron microscopy）, biochemically （DNA and 4-hydroxyproline） and mechanically. The results showed that recellularization was comparable to the specimens of hybrid scaffolds and controls. The specimens of hybrid scaffolds and controls revealed comparable amounts of cell mass and 4-hydroxyproline （P〉0.05）. However, the specimens of hybrid scaffolds showed a significant increase in mechanical strength, compared to the controls （P〈0.05）. This study demonstrated the superiority of the hybrid scaffolds to increase the mechanical strength of tissue engineered heart valves. And compared to the decellularized valve scaffolds, the hybrid scaffolds showed similar effects on the proliferation of MSCs and formation of extracellular matrix. It was believed that the hybrid scaffolds could be used for the construction of tissue engineered heart valves.

摘要：背景:利用缓释系统释放生长因子,是目前生物活性因子应用研究的方向之一。目的:应用离子交联沉淀法制备壳聚糖-转化生长因子β1缓释微球,观察其体外缓释性能以及细胞相容性。设计、时间及地点:观察性实验,于2006-10/2007-09在华中科技大学同济医学院附属协和医院中心实验室完成。材料:壳聚糖,脱乙酰度90%,由清华大学化学工程系提供;转化生长因子β1,由晶美公司提供;大鼠由华中科技大学同济医学院实验动物中心提供。方法:①离子交联沉淀法制备壳聚糖微球,并包裹转化生长因子β1,制备可体外缓释转化生长因子β1的壳聚糖-转化生长因子β1缓释微球。②选择传代二三次、生长良好的大鼠胸降主动脉中层肌成纤维细胞,调节细胞密度至1×108L-1,分别加入不同浓度(4,2,1g/L)壳聚糖微球浸提液,不含浸提液的培养基作为对照培养。主要观察指标:扫描电镜、激光粒度分析仪、Elisa法观察微球表面形态,测定药物载药率、包封率、体外缓释效率等指标;四甲基偶氮唑盐法观察细胞增殖情况,评估壳聚糖微球体外细胞相容性。结果:所得微球球形良好,表面光滑,粒径分布集中,平均粒径272nm。壳聚糖微球有较高的药物包封率,达80.60%。体外释放试验提示,转化生长因子β1初期存在突释现象,前24h释放达27%,其后可从壳聚糖微球中稳定释放,7d累计释放达41%。四甲基偶氮唑盐法提示该壳聚糖微球对细胞体外生长无不良影响,相容性好。结论:离子交联沉淀法制备壳聚糖缓释微球方法简单易行,所得壳聚糖-转化生长因子β1微球具有良好的缓释效能及细胞相容性。

摘要：如今各个城市的公共交通快速发展,公交BRT线路越来越多,如何在设计阶段优化设计方案并保证开通后能安全运营,一直是BRT车站设计的难点和重点。一般除了常规的静态分析也没有很好的评价方法。以成都二环路BRT车站为例,通过引入Legion行人仿真模拟技术,测试典型车站设计方案在正常情况、极限状态和紧急疏散情况下的运行情况,非常直观地评价其服务水平,并反馈修改设计,以达到满足客流的前提下优化设计方案的需要。模拟显示,成都BRT车站近期的服务水平良好,远期需要采取需求管理的手段控制进站客流。BRT线路开通后的实际运行情况和仿真模拟的结果基本一致,表明这种动态仿真模拟的研究方法对类似的工程设计有一定的指导和借鉴意义。

摘要：目的:探讨血管壁组织因子小干扰核糖核酸(siRNA)对大鼠血管平滑肌细胞组织因子基因沉默作用的可行性和有效性。方法:设计并合成针对大鼠组织因子的25 bp双链siRNA分子。使用组织因子siRNA、对照siRNA转染大鼠血管平滑肌细胞,同时设立空白对照,实验共分6组(各组n=5)。荧光显微镜观察转染效率。血小板源性生长因子-BB刺激血管平滑肌细胞后逆转录多聚酶链反应检测组织因子信使核糖核酸表达,免疫印迹和免疫组化检测组织因子蛋白表达。结果:siRNA成功转染到血管平滑肌细胞,转染效率约(90.0±2.3)%。3对候选siRNA筛选出基因抑制效率最高一对,与阴性对照组相比,转染24 h组织因子信使核糖核酸表达减少(86.0±0.6)%,转染48 h蛋白质印迹分析组织因子蛋白表达减少(92.0±1.0)%,同时免疫组化检测组织因子表达明显减弱。结论:RNA干扰能明显下调大鼠血管平滑肌细胞组织因子表达。

摘要：背景:已有研究显示在动脉球囊损伤模型中,动脉中层平滑肌受损后组织因子表达迅速上调,缺血再灌注损伤也会导致内皮细胞组织因子表达增加。而对于静脉移植物中组织因子表达及其机制的研究较少。目的:观察静脉移植物管壁组织因子表达变化。设计、时间及地点:动物观察性实验,于2006-05/2008-05在华中科技大学同济医学院附属协和医院心血管外科实验室完成。材料:SD大鼠30只。方法:于颈内、颈外静脉汇合处结扎颈外静脉近心端,颈外静脉远心端在发出分支前结扎离断。以无损伤血管夹夹闭颈总动脉近心端和远心端,在两血管夹中间斜形切除5mm动脉。将动脉近心端和静脉远心端吻合两针并对抗牵引,再在两针之间的前后壁分别缝合三针;离断颈外静脉近心端,将其和颈总动脉远心端吻合。主要观察指标:免疫组织化学观察管壁组织因子、增殖细胞核抗原表达,同时检测标本蛋白抽提物组织因子活性,使用计算机图像分析系统分析内膜、中膜厚度,以对侧颈外静脉作为对照。结果:所有静脉移植物血管外膜均有组织因子表达,早期静脉移植物内膜、中膜组织因子表达明显增加,晚期静脉移植物内膜、中膜无组织因子表达;对照静脉内膜、中膜无组织因子表达。术后3d静脉移植物可观察到细胞增殖核抗原蛋白阳性表达,7d明显增高,14d达到最高。对照组静脉、早期和晚期静脉移植物血管蛋白抽提物组织因子活性无统计学意义。静脉移植物内膜在术后7,14,28d增生明显,中膜在术后14,28d增生明显。结论:不同时间点静脉移植物管壁组织因子表达变化与新内膜增生相关。

摘要：The purpose of this study was to fabricate decelluarized valve scaffold modified with polyethylene glycol nanoparticles loaded with transforming growth factor-β1（TGF-β1）,by which to improve the extracellular matrix microenvironment for heart valve tissue engineering in *** glycol nanoparticles were obtained by an emulsion-crosslinking method,and their morphology was observed under a scanning electron *** valve scaffolds,prepared by using trypsinase and TritonX-100,were modified with nanoparticles by carbodiimide,and then TGF-β1 was loaded into them by *** TGF-β1 delivery of the fabricated scaffold was measured by asing enzyme-linked immunosorbent *** unseeded or reseeded with myofibroblast from rats,the morphologic,biochemical and biomechanical characteristics of hybrid scaffolds were tested and compared with decelluarized scaffolds under the same *** enzyme-linked immunosorbent assay revealed a typical delivery of *** morphologic observations and biological data analysis indicated that fabricated scaffolds possessed advantageous biocompatibility and biomechanical property beyond decelluarized *** this study proved that it was feasible to fabricate the hybrid scaffold and effective to improve extracellular matrix microenvironment,which is beneficial for an application in heart valve tissue engineering.

摘要：完善的道路交通基础设施是旅游城市进一步发展的先决条件。介绍旅游城市滨海道路因其特殊的自然地理环境在交通构成和交通出行上表现出的不同的交通特征。阐述在滨海旅游城市有限的道路交通用地空间内,如何制定适合旅游城市滨海道路的规划,采用何种设计方法,并提出滨海道路的运营策略。