Water Soluble Chitosan Derivates Grafted Onto The Surface Of Biomaterials To Improve Antithrombogenicity

Polymeric biomaterials were widely used in artificial organ or other medical devices and played an important role in biomedical application. When polymeric materials contact with living organisms, there are significant responses such as thrombus formation. Biocompatibility, particularly blood compatibility, is the most important property required for contact with blood in vivo. To improve blood compatibility of biomaterials is always an important research task for biomaterial research and development.Grafting with special structure can give polymer with proper mechanical property new surface properties and develop the blood compatibility of the biomaterials. Chitosan has a hemostatic function, and some chitosan derivates have an antithrombogenic function. In this work , Water soluble chitosan derivates were constructed onto the general biomaterials to improve their blood compatibility.(1) Surface modification of chitosan filmChitosan is chemically prepared by N-deacetylation of naturally-occurring chitin. N-methylene phosphonic chitosan (MPCS) was grafted to chitosan membrane using glutaraldehyde. Surface analysis of the grafted membrane by ATR-FTIR and ESCA and the water contact angle confirmed that N-methylene phosphonic chitosan (MPCS) were successfully grafted onto the chitosan membrane. The blood compatibility of the MPCS-grafted chitosan membrane was evaluated by platelet rich plasma contacting experiments and protein adsorption experiments. The blood compatibility of MPCS-grafted chitosan membrane is better than that of blank chitosan membrane.(2) Surface modification of polythene filmO-Butyrylchitosan(OBCS) was grafted to polythene membrane using Photograft. Surface analysis of the grafted membrane by ATR-FTIR, ESCA and the water contact angle confirmedthat O-Butyrylchitosan were successfully grafted onto the polythene membrane. The blood compatibility of the OBCS-grafted polythene films was evaluated by platelet rich plasma contacting experiments and protein adsorption experiments. The blood compatibility of OBCS grafted polythene membrane is better than that of blank polythene membrane.(3) Surface modification of Cellulose filmHemodialysis is one of the important methods for blood purification. Requirements of the hemodialysis membrane are excellent permeability for water and solute, mechanical strength and blood compatibility. Up to now, worldwide 85% of hemodialysis uses cellulose membrane. Though the cellulose membrane has both good permeability and mechanical properties, its blood compatibility needs improving for hemodialysis. In the paper, O-Butyrylchitosan(OBCS) was directly grafted onto cellulose membrane using Photograft. Surface analysis of the grafted membrane by ATR-FTIR and ESCA and the water contact angle confirmed that O-Butyrylchitosan were successfully grafted onto the cellulose membrane. The blood compatibility of the OBCS-grafted cellulose films was evaluated by platelet rich plasma contacting experiments and protein adsorption experiments. The blood compatibility of OBCS grafted cellulose film is better than that of blank cellulose film.Platelet rich plasma adhesion and protein absorption studies were used to evaluate the blood compatibility of the grafted films. No platelet adhesion was observed for the grafted films contacted with PRP. No protein absorption and platelet adhesion was detected after contact with blood. Protein absorption was also reduced compared with blank. This water soluble chitosan derivates structure grafted biomaterial might have potential biomedical applications.