Studies on Graft Copolymerisation of Vinyl Monomers onto Chitosan for Biomedical Applications скачать в хорошем качестве

Studies on Graft Copolymerisation of Vinyl Monomers onto Chitosan for Biomedical Applications

Biopolymer chitosan, the most abundant natural amino polysaccharide, and its most important derivative, chitosan, are recently considered as the subjects for extensive worldwide academic and industrial research. In spite of potential applications of chitosan, it is necessary to establish efficient appropriate modifications to explore fully their high potential. A variety of chemical modifications are employed to modify these carbohydrate polymers. Graft copolymerization, with an emphasis on the synthetic aspects. Both chemically and radiation initiated graft copolymerization of various vinyl monomers onto the trunk polymers are investigated. Meanwhile, the limited cases of poly-condensation and oxidative coupling are presented as the non-vinyl graft copolymerization methods. Then, the ring-opening graft copolymerization is described and the cases of the cyclic monomers a-aminoacid N-carboxyanhydrides and ε-caprolactone are investigated. An extensive description of the “grafting onto” approach is provided. Chitosan gels cross-linked with a hydrophobic cross-linker showed good antibacterial activity at lower degrees of cross-linking. It appears that the rigidity of the resulting macromolecule plays important role in the antibacterial activity, in addition to the hydrophobic character introduced by the cross-linker.