Effects of hyaluronic acid－chitosan－gelatin complex on the apoptosis and cell cycle of L929 cells

With the development in the field of tissue engineering, the interaction between biomaterials and cells has been deeply studied. Viewing the cells seeded on the surface of materials as an organic whole, cell cycle and apoptosis are analyzed to deepen the study of cell compatibility on biomaterials, while cell proliferation and differentiation are studied at the same time. In this paper, hyaluronic acid is incorporated into the chitosan-gelatin system. Propidium iodide (PI) was used in cell cycle analysis and the double-staining of cells with annexin-V and PI was applied in cell apoptosis analysis. The results show that incorporated hyaluronic acid shortens the adaptation period of cells on the material surface, and then cells enter the normal cell cycle quickly. In addition, added hyaluronic acid inhibits cell apoptosis triggered by the membranes. Therefore, hyaluronic acid improves the cell compatibility of chitosan-gelatin system and benefits the design of biomimetic materials.     

The multiple interactions between growth factors and microenvironment in vivo

The extracellular matrices (ECMs), which form the supportive meshwork around the cells, are largely composed of proteins and polysaccharide secreted by cells, while, growth factors, which almost all exist in ECMs, are polypeptides synthesized and secreted…     

以正己醛为载体的乳状液膜分离尿素的研究

以正己醛为载体、以氧化环糊精为内相捕捉剂制备一种新的乳状液膜，运用其清除分离尿素，旨在研究一种治疗尿毒症或缓解症状的新型疗法．实验发现，当外相尿素溶液浓度为13g／L，载体正己醛含量为5％，内相氧化环糊精浓度为15％，内相pH=10时。乳状液膜吸附容量为24.7mg／g．内相氧化环糊精的浓度对单位吸附量起决定作用，但是对吸附速率影响不大．内相pH值由于能直接影响内相捕捉剂与尿素结合物的稳定性，所以对单位吸附量有重要影响．此种吸附剂对氨基酸吸附量仅为尿素的1／10，这为其在含大量氨基酸的人体环境中有效清除尿素提供了优良的选择性，避免了其他尿毒症吸附剂普遍存在的吸附选择性低的缺点．     

聚丙烯酰胺季铵化改性及吸附染料

聚丙烯酰胺(PAM)通过胺甲基化反应后,以溴乙烷为季铵化试剂进行季铵化改性,对不同染料吸附能力的进行测试,以此评价季铵化树脂的改性程度．通过傅里叶红外对季铵化树脂分析表明,对PAM进行季铵化改性是可行的．用扫描电镜对树脂吸附染料的形貌表征表明,季铵化后的AM树脂对染料吸附性能良好,其吸附不仅有阴阳离子静电作用,还存在架桥和凝聚作用．     

聚乙烯醇缩丁醛—接枝丙烯酰胺的合成及生物医学性能

聚乙烯醇缩丁醛—接枝—丙烯酰胺共聚物已采用硝酸铈铵/硝酸引发体系于水悬浮液中在30℃合成,接枝长度和每个聚乙烯醇缩丁醛分子上支链的数几分别确定为(?)n3-6×10~4和0.1-0.3。测定了反应时间和铈离子浓度对接枝率,接枝长度和支链数目的影响。亦讨论了其他反应参数的影响,并研究了此聚合物的吸水率,对牛血清白蛋白的粘附及血液相容悱。结果表明此共聚物当接枝率为15—25%而平均接枝链长度((?)n)大于4×10~4其血液相容性良好。