胶原膜与聚-β-羟基丁酯在组织工程心脏瓣膜中应用的研究

目的 :对胶原膜与聚 β 羟基丁酯在组织工程心脏瓣膜技术中的应用进行比较。方法 :对照研究胶原膜和聚 β 羟基丁酯膜在材料结构、皮下包埋和细胞生长对照实验情况。结果 :胶原膜呈网孔状结构 ,皮下包埋8周仍保持膜状结构 ,皮下包埋 8～ 12周完全降解 ,生物相容性优于聚β羟基丁酯膜。结论 :胶原膜在材料结构特征、降解率和生物组织相容性方面均优于聚β羟基丁酯 。

大鼠皮下植入新型生物可降解材料聚-β-羟基丁酯的生物相容性

目的：评价生物可降解材料聚－β－羟基丁酯（ｐｏｌｙ－３－ｈｙｄｒｏｘｙｂｕｒａｔｅ，ＰＨＢ）的生物相容性．方法：８０只雄性Ｗｉｓｔａｒ大鼠皮下植入ＰＨＢ，分别在０．５，１，３，６ｍｏ取出，研究其周围的组织反应和ＰＨＢ的降解情况．结果：ＰＨＢ能被组织很好的相容，在其植入的临近部位无急性炎症反应，无脓肿形成及组织坏死发生．取材分别做ＨＥ染色，Ｖａｎ－Ｇｉｅｓｏｎ染色，在０．５，１，３，６ｍｏ比较纤维包膜的厚度及各种炎细胞浸润程度．在０．５ｍｏ组炎细胞以中性粒细胞为主，纤维包膜疏松相对较薄；在１ｍｏ，３ｍｏ组炎细胞总数下降，淋巴细胞比例高于中性粒细胞，纤维包膜致密，胶原纤维成分增多；６ｍｏ组炎细胞数进一步减少，成纤维细胞明显减少，纤维包膜变薄而致密．植入的ＰＨＢ在２ｗｋ内引起轻微的反应，在１ｍｏ～３ｍｏ后反应明显下降，６ｍｏ后ＰＨＢ出现部份降解．结论：ＰＨＢ植入引起的组织反应变化轻微，有较好的生物相容性，且有部分降解，是具有应用前景的生物可降解材料．

Study on Kinetics of Dissolving Biomass Using Sodium Hypochlorite in the Recovery of Poly-β-hydroxybutyrate

The effects of sodium hypochlorite concentration in the recovery of poly-β-hydroxybutyrate (PHB) are investigated. A simple reaction equation and a mathematical model describe the reaction kinetics. Results showed that the stoichiometric coefficient increases with increasing CAO/CBO, where CAO is the concentration of the active chlorine at t = 0 and CBO is the initial concentration of the non-PHB materials.

可降解聚合物在组织工程心脏瓣膜中应用的皮下埋植实验研究

目的 :评价作为组织工程心脏瓣膜支架的聚羟乙酸 聚乳酸共聚物 (PGLA)、聚 β 羟基丁酯 (polyhydroxybu tyrate ,PHB)、胶原膜三种生物可吸收材料的组织相容性和皮下吸收情况。 方法 :本文对照研究三种材料经皮下埋植后 2、4、6、8周和 12周的大体观察及组织学检查。 结果 :胶原膜皮下包埋 8周仍保持膜状结构 ,8～ 12周完全降解 ,组织相容性及皮下吸收情况优于PHB及PGLA。 结论

Simultaneous Expression of Vitreoscilla Globin Gene and Lytic Genes of Phage A in a Novel Recombinant Escherichia Coli Used for Production of PHB

Exogenous Vitreoscilla globin gene (vgb), lytic genes of phage A with S amber mutation (S-RRz) and poly(B-hydroxybutyrate) (PHB) biosynthetic genes (phbCAB) were cloned into a same Escherichia coli cell, simultaneously or respectively. Six novel strains containing phbCAB and vgb with or without lytic genes were constructed. Strain VG1 (pTU14), in which vgb, phbCAB and S-RRz could all be successfully expressed, has superior characteristics in cell growth and PHB accumulation, while the results of strains containing vgb and phbCAB without S- RRz were not better than that of strains harbored ph&CAB only. The simultaneous expression of vgb and S- RRz in the recombinant VG1 (pTU14) showed a great potential for low-cost production of PHB.