Preparation Of Molecularly Imprinted Polymer And Surface Modification Of Biomedical Materials Through LbL Assembly Of Carboxymethyl Cellulose And Lysozyme

The layer-by-layer (LbL) assembly method possesses extraordinary advantages for biomedical applications:ease of preparation, versatility, capability of incorporating high loadings of different types of biomolecules in the films, fine control over the materials'structure, robustness of the products under ambient and physiological conditions and capability of retaining biomolecules'structure and biological activity. In this context, the layer-by-layer assembly of carboxymethyl cellulose and lysozyme was used to prepare lysozyme imprinted polymer and modify the surface properties of polyurethane.First, a lysozyme imprinted polymer was prepared by LbL assembly technique and molecular imprinting technique, with carboxymethyl cellulose as natural functional monomer and lysozyme as template protein. The positively charged lysozyme and negatively charged carboxymethyl cellulose were alternately deposited onto the surface of the carboxymethyl cellulose film. After reacted with ferric chloride and eluted by aqueous containing5M sodium chloride, the lysozyme imprinted polymer was prepared. The adsorption capacity of imprinted polymer for template protein increased about50%compared to the non-imprinted polymer. The imprinted polymer exhibited high selectivity for lysozyme compared to the model protein bovine serum albumin. The imprinted polymer could be used repeatedly for several times.Second, positively charged amino groups were introduced to the surface of polyurethane. Then, negatively charged carboxymethyl and positively charged lysozyme were alternatively deposited onto polyurethane surface through LbL technique. The results showed that the modified polyurethane possessed antibacterial activity against Escherichia coli and Staphylococcus aureus, the number of viable Escherichia coli and Staphylococcus aureus on the modified surface decreased by45.5%and41.4%, respectively. Moreover, the hemolysis test demonstrated that the modified polyurethane had a better blood compatibility.This work takes advantage of lysozyme and carboxymethyl cellulose to prepare lysozyme imprinted polymer and surface modify of polyurethane through LbL technique. It can provide effective methods for selectively adsorption of protein and surface modification of bio-medical materials.