Biomembranes as models for polymer surfaces: IV. ESCA analyses of a phosphorylcholine surface covalentiy bound to hydroxylated substrates☆
Abstract Using a simple chemical process, phosphorylcholine has been deposited covalentiy on the surface of a variety of hydroxylated polymers as a stable, monomolecular coating. Our goal was to obtain new biomaterials which, due to the chemical similarity of the modified interfaces to the phospholipid head groups present on the extracellular surfaces of blood cell membranes, should exhibit enhanced haemo- and biocompatibility. Our previous analyses by chemical and spectrophotometric methods indicated that sufficient quantities of phosphorylcholine were deposited on glass and silica surfaces to result in appreciable modification of their interfacial properties. In the present study, we have examined a series of modified hydroxylated substrates by ESCA and demonstrate specific chemical modifications on the molecular surfaces of polymeric substrates.
Objective:In order to enhance the anti-tumor activity of polysaccharide compound,to establish the method for the content determination of the polysaccharides.Method:On the basis of the traditional water extraction and alcohol precipitation,it adopted a preliminary purification process of anhydrous ethanol,ethyl ether,acetone.It applies of the anthrone sulfuric acid method of determination of polysaccharide.Result:After a preliminary purification procedure of polysaccharides,the compound gets the compound content of 24.9%.Conclusion:The method is simple and stable.It can be used for determination of the polysaccharides.