分子水平上调控细胞粘附和分离体系的构建-生物工程专业论文.docx

华 华 中 科 技 大 学 硕 士 学 位 论 文 II II Abstract Biological materials science, known as an important interdisciplinary subject between two areas- materials science and life science that have mutual penetration of each other, has made many breakthroughs and progresses in recent years due to the fundamental reason of the healthy needs of people and economical development, which make the fields in biocompatible materials, tissue engineering, nano-biomaterials, bio-mineralized materials and biomimetic smart materials become the research frontier of biological materials. This thesis mainly focus on the synthesis of artificial proteins and thermoresponsive polymers, which we use to fabricate a thermoresponsive system on the gold surface to regulate the cell adhesion and cell detachment in combination with the advantages of both of the two materials. The main results are summarized as follows: Approaches of molecular biology are introduced to fabricate the plasmids and induce the expression of artificial polypeptide Bcys, NcysA, and NcysARGD. These materials are perfectly biocompatible because they are produced through genetic engineering methods and at the same time, they can be manipulated to add, remove or change the amino acid’ sequence in molecular level by easily cloning different DNA sequences so as to connect other thermoresponsive or photoresponsive materials and get some complex characteristics. Meanwhile, molecular recognition between the pair of complementary leucine zipper domains A and B, which heterodimerized through noncovalent, reversible interaction, indicated their application in fabrication of complicated system. A thermoresponsive polymer mPEG-PNIPAM-B, in which artificial protein B and PEG are fused, is created through RAFT polymerization reaction and other chemical modification methods, and the thermoresponsive effect do not disappear with the fusion of B and PEG. The molecular structure of PNIPAM can be stretched and shrinked by lowering or raisi