ACA微胶囊固定化细胞发酵木糖醇

考察了以游离酵母细胞、海藻酸钠固定化细胞、壳聚糖 /海藻酸钠 (ACA)微胶囊固定化细胞的木糖醇发酵 ,发现与游离、海藻酸钠固定化发酵相比 ,微囊化发酵转化率更高、更稳定。其转化率稳定在 65 %左右 ,发酵周期约为 5 0h。

副干酪乳杆菌的功能特性及其应用研究进展

副干酪乳杆菌(Lactobacillus paracasei)属于乳杆菌属,是一种革兰氏阳性细菌。它不仅具有抑菌和免疫调节性能,对人体有很好的益生作用,而且可以用于代谢合成重要的生物化学品,近几年引起了国内外的关注。本文对副干酪乳杆菌的菌株筛选鉴定、功能特性及其在微胶囊技术、L-乳酸生产、苯乳酸合成等方面的应用研究进展等进行了综述,同时对其研究发展方向进行了探讨。

Continuous release of interleukin 12 from microencapsulated engineered cells for colon cancer therapy

AIM: To explore the anti-tumor immunity against CT26 colon tumor of the microencapsulated cells modified with murine interleukine-12 (mIL-12) gene.METHODS: Mouse fibroblasts (NIH3T3) were stably transfected to express mIL-12 using expression plasmids carrying mIL-12 gene (p35 and p40), and NIH3T3-mIL-12cells were encapsulated in alginate microcapsules for longterm delivery of mIL-12. mIL-12 released from the microencapsulated NIH3T3-mIL-12 cells was confirmed using ELISA assay. Transplantation of the microencapsulated NIH3T3-mIL-12 cells was performed in the tumor-bearing mice with CT26 cells. The anti-tumor responses and the anti-tumor activities of the microencapsulated NIH3T3-mIL12 cells were evaluated.RESULTS: Microencapsulated NIH3T3-mIL-12 cells could release mIL-12 continuously and stably for a long time. After the microencapsulated NIH3T3-mIL-12 cells were transplanted subcutaneously into the tumor-bearing mice for 21 d, the serum concentrations of mIL-12, mIL-2 and mIFN-γ the cytotoxicity of the CTL from the splenocytes and the NK activity in the treatment group were significantly higher than those in the controls. Moreover, mIL-12 released from the microencapsulated NIH3T3-mIL-12 cells resulted in a significant inhibition of tumor proliferation and a prolonged survival of tumor-bearing mice.CONCLUSION: The microencapsulated NIH3T3-mIL-12cells have a significant therapeutic effect on the experimental colon tumor by activating anti-tumor immune responses in vivo. Microencapsulated and genetically engineered cells may be an extremely versatile tool for tumor gene therapy.

基于电沉积法制备海藻酸钙水凝胶的研究进展

海藻酸钙水凝胶具有高度的吸水性、生物相容性和可降解性,在组织工程领域有着十分广泛的应用。海藻酸钠溶液与钙离子的直接反应是目前制备海藻酸钙水凝胶最常用的方法。然而,该方法中的钙离子在溶液中是自由扩散的,不能控制凝胶的结构,限制了海藻酸钙水凝胶的应用。因此,如何制作特定结构的海藻酸钙水凝胶,近年来成为了研究者的研究热点。基于电沉积法制备海藻酸钙水凝胶,可以控制钙离子析出的数量和位置,能够得到任意结构的海藻酸钙水凝胶。本文综述了电沉积法制作海藻酸钙水凝胶的原理,讨论影响电沉积法成胶的因素,对电沉积法的应用与发展进行概述和展望。