Surface Modification Of Medical Polymer Materials By Lentinan And Its Derivatives

Polymeric biomaterials have been widely used on reparation, replacement and regeneration of biological organism, which directly relate with human health. The surface properties and biocompatibility of polymeric biomaterials play an important role in its applications. Surface modification is the most direct and effective method to improve the surface properties and biocompatibility of biomaterials.In this work, lentinan was extracted from Lentinus Edodes (shiitake mushroom), and its derivatives were prepared. Then, lentinan and its derivatives were immobilized on the surfaces of polymeric biomaterial by different methods. The surface properties, biocompatibility and bioactivities of the modified materials were studied.The photo-reactive lentinan was synthesized at first, and then immobilized on polyurethane surfaces by photochemical reaction. The analytical results show that the hydrophilicity and cytocompatibility of polyurethane surfaces have been improved after modification. The results of hemolysis test and thrombus test demonstrate that the blood compatibility has also been improved after modification. In addition, the modified surfaces indicate clear antibacterial activity against Escherichia coli.After the preparation of azido-chitosan, lentinan sulfate and azido-chitosan were alternatively deposited on polyurethane surfaces through layer-by-layer self-assembly technique. Then, the self-assembled multilayers on the surface were cross-linked by photochemical reaction. The analytical results show that the modified surface became more hydrophilic. The number of viable bacteria on self-assembled surfaces decrease 57% compared to native polyurethane. Moreover, the blood compatibility has been improved after surface modification.The cross-linked chitosan substrate were prepared firstly, and lentinan sulfate and chitosan were alternatively deposited on the surface through layer-by-layer self-assembly technique. The results indicate that the hydrophilicity and blood compatibility of the modified surface have been improved. At the same time, the modified surfaces indicate excellent antibacterial activity against Escherichia coli.This work provides scientific data and valuable experiences for preparing biocompatible materials with multi-function and specific bioactivity. It also can provide an effective method for the immobilization of fungal polysaccharides and its derivatives on polymeric biomaterials.