离心力在体外构建组织工程软骨中的作用

目的探讨离心力对软骨细胞功能表达和组织工程软骨结构的影响。方法采用组织化学和免疫组织化学观察组织工程软骨结构以及Ⅱ型胶原表达情况,应用DMMB分光法测定组织工程软骨硫酸化糖胺多糖(GAG)的含量。结果体外培养2、4、8周时,静态培养的组织较离心培养的组织Ⅱ胶原免疫组织化学染色弱;并且其GAG含量低于离心培养组织GAG含量,各组差异均有统计学意义(F分别为12.3、10.2、9.1,P<0.05)。离心培养的组织工程软骨GAG含量于第4周达到高峰,均值为(7.60±0.79)%。结论离心力刺激软骨细胞分泌GAG和Ⅱ型胶原,并且影响组织工程软骨结构的排列。     

Experimental Study on Allogenic Decalcified Bone Matrix as Carrier for Bone Tissue Engineering

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rab-bits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as con-trol. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts,trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the sur-face of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good bio-compatibility and ectopic induced osteogentic activty.     

胶原材料在药物缓释和组织工程中的研究进展

目的介绍胶原材料在药物缓释和组织工程中的研究新进展. 方法广泛查阅近年相关文献并进行回顾与综合分析. 结果胶原材料在药物缓释与组织工程中的应用研究已取得明显进展,胶原材料已成为组织工程研究的热点之一.一些胶原基质新型药物缓释系统和新型组织工程材料已进入临床论证阶段,将促进胶原材料在组织修复中的临床应用. 结论胶原材料在药物缓释、尤其是组织工程领域具有广阔的应用前景.除将胶原适当交联处理或与其它天然或合成高分子复合外,今后的研究中还应注重利用化学修饰改善胶原性能,通过将性质不同的支链接枝到胶原大分子上,赋予胶原新的特性,从而研制出新一代组织工程材料.     

医疗仪器的人因工程学设计

人因工程学是一门边缘性应用科学，对医疗仪器的设计有重要的指导作用；本文论述了医疗仪器设计中必须考虑的人因工程学因素，包括人体对作业负荷的耐受性、人体尺度、人体的生物力学特性、人的适宜劳动姿势、人机界面、作业空间、安全性和维修性等。     

生理影像信息技术及其临床应用

生理影像是功能性医学影像的一个重要分支,也是临床医学工程的一个极其重要的研究和应用领域。多年来,作者及其研究生与临床医务人员相结合,在电生理影像和热生理影像的信息获取和数字化处理技术方面进行了大量及深入的研究,提出了一种体内热估计(ITE)新技术。本文重点介绍热生理影像信息在妇女乳腺癌诊断中的应用。通过对约五千例妇女乳腺病筛选的结果,表明了生理影像信息处理及ITE技术在临床医学上的应用价值。     

戊二醛交联提高胶原/壳聚糖真皮支架抗细胞收缩能力的研究

目的 应用交联处理的胶原支架,来减缓其降解过多、易收缩变形、机械性能不足等缺点.方法 采用冷冻-冻干法构建胶原/壳聚糖多孔支架,并通过戊二醛交联构建具有良好抗细胞收缩稳定性和细胞相容性的胶原支架.通过测定不同培养时间各类支架的尺寸变化,研究了戊二醛交联对支架抗细胞收缩能力的影响.结果 戊二醛交联后的胶原/壳聚糖支架未见明显收缩,其细胞活性也始终高于干热交联支架.结论 戊二醛能有效地提高胶原基支架的抗细胞收缩能力,并保持其良好的生物相容性.     

脂肪干细胞/Ⅰ型胶原凝胶复合体的构建及其体内外成骨分化研究

目的探讨利用脂肪干细胞与Ⅰ型胶原凝胶复合构建新型骨组织工程复合体的可行性并对其体内外成骨分化情况进行分析。方法取3月龄日本大耳白兔肩胛部皮下脂肪，Ⅰ型胶原酶消化获得细胞，于体外依次进行骨、软骨、脂肪多向诱导分化鉴定；取第3代细胞与Ⅰ型胶原凝胶复合，于成骨诱导条件下体外培养，相差显微镜、扫描电镜观察复合情况并对其碱性磷酸酶、细胞外基质矿化程度进行检测，同时设立单层贴壁培养细胞作为对照（n=4）；两周后移植于裸鼠皮下，12周后处死动物，依次行放射学、组织学检测观察成骨情况（n=3）。结果（1）所获细胞具备骨、软骨、脂肪多向分化潜能，为多能干细胞。（2）形态学观察显示脂肪干细胞呈三维立体生长状态，均匀、高密度悬浮于Ⅰ型胶原凝胶中。在体外成骨诱导条件下，其碱性磷酸酶活性以及外基质矿化程度均显著高于单层贴壁培养细胞（P〈0．01，n=4）。（3）于裸鼠皮下移植12周后，放射学、组织学检测显示脂肪干细胞．Ⅰ型胶原凝胶复合体成骨明显（n=3）。结论（1）IⅠ型胶原凝胶可显著促进脂肪干细胞的成骨分化。（2）作为一种新型的骨组织工程复合物，脂肪干细胞-Ⅰ型胶原凝胶复合体可应用于骨组织工程，特别是腔隙性骨缺损的修复过程。     

不同持续时间的周期性压力对构建组织工程软骨的影响

Objective To determine the best duration for exerting the cyclic pressure under which the tissue-engineered cartilage is constructed. Methods Free chondrocytes isolated from rabbit articular cartilage were seeded into polylactic acid-co-glycolic acid(PLGA) scaffolds after expansion in vitro, and ran-domized into 4 groups. In Groups 1 to 3, chondrocytes were cultured under daily cyclic pressure (0 ～ 200 kPa, 0.1Hz) for 4 hours, 8 hours, 12 hours respectively; Group 4 was a control in which no pressure was exerted. In each group, after 2 weeks of culture, the tissue engineered cartilages were observed in vitro and assessed by his-tological staining of liE. Next, the content of DNA and the secretion of type Ⅱ collagen and GAG in cartilages were detected quantitatively. Results Under the daily cyclic pressure (0 ～200 kPa, 0.1 Hz), the scaf-fold-chondrocytes complex in the group of 8 hours got the largest volume, smooth, lucidus, and elastic surface, the most queuing chondrocytes, and the highest content of type Ⅱ collagen and GAG (P < 0.01). Conclusions Since chondrecytes are baro-senstive, the metabolism of chondrocytes can be affected by the time of cyclic pressure. Under the effect of 0 ～200 kPa, 0.1Hz, the daily cyclic pressure of 8 hours may be optimal for chondrocytes to multiply and synthesize extracellular matrixes such as type Ⅱ collagen and GAG.     

骨髓间充质细胞与速固化磷酸钙支架共培养的实验研究

[目的]观察人骨髓间充质干细胞在速固化磷酸钙骨水泥支架中的增殖和生长情况。[方法]将速固化壳聚糖-磷酸钙骨水泥支架材料预先成形。采用全骨髓法分离人骨髓间充质细胞并在体外对细胞进行培养和扩增。72h首次换液,细胞融合80%传代,取第3代细胞用于实验。将细胞与磷酸钙骨水泥支架复合培养,分别利用四甲基偶氮唑蓝MTT法及扫描电镜等检测细胞在材料中的增殖和生长情况。[结果]用酶标仪检测OD值提示共培养后,支架内的细胞数量逐渐增加。扫描电镜结果显示支架材料内部为多孔结构,孔内见有细胞生长,细胞表面可见分泌颗粒。[结论]速固化壳聚糖-磷酸钙骨水泥对人骨髓间充质干细胞有较好的细胞相容性,细胞可在材料内黏附和增殖,是理想的骨组织工程支架材料。     

管状膨体聚四氟乙烯用于组织工程支架材料的动物实验研究

目的：研究膨体聚四氟乙烯(ePTFE)植入动物体内后与机体的关系。方法：管状膨体聚四氟乙烯两端闭合，内充DMEM培养液，埋入家兔皮下，观察宿主生命情况，于术后1、2、4、6周取出标本，行大体及光镜下观察。结果：家兔在植入膨体聚四氟乙烯材料及DMEM培养液后存活情况良好，DMEM培养液在1周时即已完全无色透明；4周时膨体聚四氟乙烯与周围组织有粘连，6周时粘连紧密；光镜下观察，各时间点材料间隙均可见着色，1周时可见少量淋巴细胞浸润，无血管及组织细胞。材料内壁未见细胞附着。结论：植入膨体聚四氟乙烯材料及少量DMEM培养液对宿主动物存活无影响；管内外液体可相互交通，管状膨体聚四氟乙烯可作为组织工程化尿道的支架材料。