脱细胞真皮基质的制备与性能分析

目的 制备一种新型脱细胞真皮基质(ADM)并分析其性能。方法 选用猪皮为原料,采用化学、物理及生物综合技术制备ADM,采用HE染色、扫描电子显微镜观察、红外光谱分析、氨基酸分析、拉力实验、MTT法检测其外观、结构及理化性能。结果 ADM细胞去除彻底,胶原蛋白的含量达92.01%;具有连通的三维孔道,孔径约100μm;红外吸收符合胶原蛋白的吸收特征,保持了胶原纤维的天然结构;透水汽性达到每天2923g/m2;孔隙率提高到85.54%;细胞在ADM上黏附生长、增殖良好、分布均匀。结论 ADM孔隙率和拉伸强度适宜、孔结构理想、降解速度可控、生物相容性良好,符合皮肤组织工程对支架材料的要求。     

泪小管显微吻合术的疗效观察及预后影响因素分析

目的探讨泪小管显微吻合术的疗效观察及预后影响因素。方法分为切开泪囊逆行插管吻合法68例和直接插管吻合法60例。观察两种方法临床疗效,观察预后影响因素。结果切开泪囊逆行插管吻合法总有效率86．76％和直接插管吻合法总有效率91．66％;两种方法总有效率比较P〉0．05,差异无统计学意义。结论泪小管显微吻合术治疗外伤性泪管断裂具有手术野层次清晰;操作精细、准确,对组织损伤极小,在手术过程中寻找鼻侧断端很关键,可采用多种方法应用,以达到最大程度促进创伤的恢复,减少手术失败率,促进患者康复。     

Preparation of Dashanzha Wan by three-dimensional printingOA

Objective: To use three-dimensional(3D) printing technology to prepare Dashanzha Wan.Methods: The standard formula proportion of Dashanzha Wan was used to prepare printable materials(normally called the ink) for 3D printing, and different doses and shapes of Dashanzha Wan were prepared. Then, the rheological properties, texture characteristics, scanning electron microscopy, and content of ursolic acid were evaluated.Results: Dashanzha Wan ink showed good shear thinning properties, which is very ...     

维药骆驼刺种子微形态特征的研究

应用光学显微镜和扫描电镜，结合野外调查结果，对维吾尔族习用药骆驼刺的种子微形态特征进行了对比分析，结果表明：不同地方居群的骆驼刺在种子微形态特征方面存在着极大的相似性，种子形状均为肾形，表面纹饰基本为条纹状，各居群间在条纹的粗细、长短和曲折程度方面存在一定差异，这些特征反映了骆驼刺种子徽形态特征的稳定性和生态因素的影响及居群变异的普遍性。     

氧化锂含量对牙科云母微晶玻璃析晶性能的影响

目的:研究Li2O对SiO2-Al2O3-MgO-Na2O-K3O-F云母玻璃陶瓷析晶性能、显微结构和抗弯强度的影响.方法:在玻璃基础成分中添加不同含量的Li2O,由差热分析(DTA)曲线确定热处理制度,采用X射线衍射分析(XRD)、扫描电子显微镜(SEM)和三点弯曲强度测试来观测和比较晶体成分、形貌和材料的力学性能.结果:3组玻璃的核化温度为530℃,最适晶化温度随Li2O含量的增加而降低.680℃热处理1 h后,含4%Li2O的母体玻璃析出的云母晶体发育完全,抗弯强度最高(183.82±12.47)MPa.结论:添加一定量的Li2O有助于改善SiO2-Al2O3-MgO-Na2O-K2O-F系云母玻璃陶瓷的析晶性能和力学强度.     

Nerve guides manufactured from photocurable polymers to aid peripheral nerve repair

The peripheral nervous system has a limited innate capacity for self-repair following injury, and surgical intervention is often required. For injuries greater than a few millimeters autografting is standard practice although it is associated with donor site morbidity and is limited in its availability. Because of this, nerve guidance conduits (NGCs) can be viewed as an advantageous alternative, but currently have limited efficacy for short and large injury gaps in comparison to autograft. Current commercially available NGC designs rely on existing regulatory approved materials and traditional production methods, limiting improvement of their design. The aim of this study was to establish a novel method for NGC manufacture using a custom built laser-based microstereolithography (μSL) setup that incorporated a 405 nm laser source to produce 3D constructs with ∼50 μm resolution from a photocurable poly(ethylene glycol) resin. These were evaluated by SEM, in vitro neuronal, Schwann and dorsal root ganglion culture and in vivo using a thy-1-YFP-H mouse common fibular nerve injury model. NGCs with dimensions of 1 mm internal diameter × 5 mm length with a wall thickness of 250 μm were fabricated and capable of supporting re-innervation across a 3 mm injury gap after 21 days, with results close to that of an autograft control. The study provides a technology platform for the rapid microfabrication of biocompatible materials, a novel method for in vivo evaluation, and a benchmark for future development in more advanced NGC designs, biodegradable and larger device sizes, and longer-term implantation studies.     

The phenotype of cancer cell invasion controlled by fibril diameter and pore size of 3D collagen networks

The behavior of cancer cells is strongly influenced by the properties of extracellular microenvironments, including topology, mechanics and composition. As topological and mechanical properties of the extracellular matrix are hard to access and control for in-depth studies of underlying mechanisms in vivo, defined biomimetic in vitro models are needed. Herein we show, how pore size and fibril diameter of collagen I networks distinctively regulate cancer cell morphology and invasion. Three-dimensional collagen I matrices with a tight control of pore size, fibril diameter and stiffness were reconstituted by adjustment of concentration and pH value during matrix reconstitution. At first, a detailed analysis of topology and mechanics of matrices using confocal laser scanning microscopy, image analysis tools and force spectroscopy indicate pore size and not fibril diameter as the major determinant of matrix elasticity. Secondly, by using two different breast cancer cell lines (MDA-MB-231 and MCF-7), we demonstrate collagen fibril diameter – and not pore size – to primarily regulate cell morphology, cluster formation and invasion. Invasiveness increased and clustering decreased with increasing fibril diameter for both, the highly invasive MDA-MB-231 cells with mesenchymal migratory phenotype and the MCF-7 cells with amoeboid migratory phenotype. As this behavior was independent of overall pore size, matrix elasticity is shown to be not the major determinant of the cell characteristics. Our work emphasizes the complex relationship between structural-mechanical properties of the extracellular matrix and invasive behavior of cancer cells. It suggests a correlation of migratory and invasive phenotype of cancer cells in dependence on topological and mechanical features of the length scale of single fibrils and not on coarse-grained network properties.     

Surface topography enhances differentiation of mesenchymal stem cells towards osteogenic and adipogenic lineages

Surface topography impacts on cell growth and differentiation, but it is not trivial to generate defined surface structures and to assess the relevance of specific topographic parameters. In this study, we have systematically compared in vitro differentiation of mesenchymal stem cells (MSCs) on a variety of groove/ridge structures. Micro- and nano-patterns were generated in polyimide using reactive ion etching or multi beam laser interference, respectively. These structures affected cell spreading and orientation of human MSCs, which was also reflected in focal adhesions morphology and size. Time-lapse demonstrated directed migration parallel to the nano-patterns. Overall, surface patterns clearly enhanced differentiation of MSCs towards specific lineages: 15 μm ridges increased adipogenic differentiation whereas 2 μm ridges enhanced osteogenic differentiation. Notably, nano-patterns with a periodicity of 650 nm increased differentiation towards both osteogenic and adipogenic lineages. However, in absence of differentiation media surface structures did neither induce differentiation, nor lineage-specific gene expression changes. Furthermore, nanostructures did not affect the YAP/TAZ complex, which is activated by substrate stiffness. Our results provide further insight into how structuring of tailored biomaterials and implant interfaces – e.g. by multi beam laser interference in sub-micrometer scale – do not induce differentiation of MSCs per se, but support their directed differentiation.     

颅缝的微观生物力学及其临床意义

本文通过尸颅颅缝的光镜和扫描电镜观察,探讨颅缝微观结构的力学特性,评估其在颅脑外伤中的价值.胶原纤维是构成颅缝的主要承力结构.它们按一定方向分布,部分使骨间结合更牢固,部分对抗骨间过度靠拢.颅缝能维持自身宽度,可防止骨间融合及缓冲外力作用.头部受暴力时,胶原纤维的连结可吸收一定能量,使压力波传播衰减,有利于减轻脑损伤.颅缝这种薄壳结构因缝连结的存在增强了脑保护的能力.老年人骨缝骨化,是容易发生脑损伤的因素之一.     

单味北芪对老龄鼠及模型鼠免疫功能的影响

本文实验结果表明,北芪能增强老龄鼠及氢化可的松致免疲功能低下模型鼠的免疫功能,提高细胞免疫、体液免疫、补体水平、CMSC活性,使老龄鼠免疫器官和组织超微结构恢复正常。从而证实,AMB能调节老龄鼠的免疫功能,是一种良好的免疫调节剂。