Preparation of Polymer Films with Different Surface Morphologies and in Vitro Cell Culture
|School||Beijing University of Chemical Technology|
|Course||Materials Science and Engineering|
|Keywords||Poly ( glycine ethyl ester - alanine ethyl ester ) phosphazene Surface patterning Osteoblasts|
Polyphosphazene nitrogen by alternating single and double bonds of the phosphorus element in an alternating constituting the inorganic main chain, the polymer of the organic group as a side group, which allows them both to the performance of the inorganic and organic polymers, can be applied to the aerospace, petroleum, military, biomedical and other fields. In the biomedical field, the most widely used is a biodegradable polyphosphazene, This is mainly because of different side chain groups can greatly affect Polyphosphazene hydrolysis of the main chain of the performance, such that its degradation speed controllable, and its The degradation product is generally non-toxic phosphate, ammonium salts and the corresponding side groups, does not cause inflammatory reactions. Ideal as a class biomedical polymer materials, POLYPHOSPHAZENE U.S. FDA certification, has been extensively studied and applied. Based on the study of regeneration and repair of the implant materials, the interaction between the surface properties of the material and cells is one of the key factors, because the cells only adhere to the surface of the material, in order to achieve its functioning. Having a specific surface topology of the artificial substrata has been widely used in the regulation of cell adhesion, proliferation and differentiation. Application coating, etching, electro-spinning, and the graft and other methods, can be constructed on the material surface of the topological structure of the different features, such as grooved, microporous, for research and cell interactions. But the majority of these studies is in metal, inorganic and abiotic degradation on the polymer substrate, fewer have conducted similar studies in the biodegradable polymer surface. Therefore, this thesis of the casting POLYPHOSPHAZENE in a high humidity environment film formation, and the film has a different surface morphology characterized by cells in vitro study of cell adhesion, proliferation and differentiation the impact. 1 by melt ring-opening polymerization, side nucleophilic substitution method, the preparation of poly (glycine ethyl ester - alanine ethyl ester) phosphazene (PAgP) and lactic acid - glycolic acid copolymer (PLGA7030), and by 1H- NMR, GPC and intrinsic viscosity number of other methods to characterize the nature of its structure, composition and molecular weight, etc.; 2 using solution casting method, prepared PAGP and PLGA7030 polymer film in a different humidity environment, and through SEM and AFM XPS and water contact angle were used to characterize the surface properties of the membrane. Found that changing the solution concentration and ambient relative humidity, can significantly change Polyphosphazene casting surface of the film morphology and composition, the a Polyphosphazene film prepared under a high relative humidity environment will form a patterned surface, and the affinity with water The high polarity of the atoms (such as P and N) exhibit the phenomenon of enrichment of the surface thereof; 3 of the polymer film of the protein adsorption experiments and cell adhesion and proliferation experiments, the results show that the high surface roughness of the pattern of Polyphosphazene membrane in the unit area can be adsorbed more protein, this feature into bone cells OCT-1 mice easier adhesion, proliferation faster; by osteoblasts cultured in vitro experiments, conducted alkaline phosphatase (ALP) activity, calcium deposits and testing of type I collagen synthesis, and study the impact of the the polyphosphazene membrane of the osteoblast differentiation. The results showed that the improvement of surface roughness and increasing the content of P element can promote the differentiation of the mouse bone cells OCT-1 and functional expression.