Synthesis And Biological Evaluation Of Chitosan Derivatives With O-substituted Quaternary Ammonium Salts

Objective:Chitosan(CS)is the only alkalic polysaccharide with amino existing in the nature,which is a kind of safe natural polymer biomaterias bearing good biodegradability,biocompatibility,bacteriostasis,adsorbability,hygroscopicity etc.However,the application is restricted because of the poor soubility of chitosan in water,alkaline solution and most of organic solvent.Therefore,it will be great importance to improve its water-solubility by the structural modification for the extension of its application.Quaternary ammonium chitosan is a type of important chitosan derivatives,which not only possesses the nature of quaternary ammonium salt like antibacterial and moisturizing but also maintains the property of the chitosan,such as film-forming,biocompatibility and biodegradability properties etc.It has widely applied value in the area of medical material,food and textile processing and other fields.Methods:This paper mainly includes the following contents:1.The synthesis of O-chitosan quaternary ammonium derivativesThe derivatives were synthesized using hydroxyl quaternary ammonium salt and chitosan and were characterized by IR,1H NMR.The average molecular weight,thermostability and degree of substitution were analyzed through Ubbelohde viacometer,thermogravimetric and element analysis,respectively.2.The antibacterial test of O-chitosan quaternary ammonium derivativesThe antibacterial performance was measured by paper and shaking culture methods against bacteria(gram-positive bacteria and gram-negtive bacteria)and fungus.3.The toxicity test of O-chitosan quaternary ammonium derivativesThe toxicity against red blood cells was detected by hemolytic test,and the toxicity against ATII cells was determined by CCK-8 method.4.The preparation of composite membraneThe composite membrane was prepared with C14QAS-CS derivatives and sodium alginate.The morphology of its side and surface was observed by scanning election microscope.The swelling property of the composite film was tested.Meanwhile,the antibacterial activity of them was also studied.Results:In summary,this paper synthesized five O-chitosan quaternary ammonium derivatives and the biological activity of them was evaluated.The results indicate the solubility and antibacterial performance of O-chitosan quaternary ammonium derivatives were grater than those of chitosan.More importantly,C14QAS-CS is almost no toxicity.Conclusion:This paper synthesized O-chitosan quaternary ammonium derivatives in this method,whichi keeped amino of chitosan.The results indicate the antibacterial performance of O-chitosan is provided.C14QAS-CS is almost non-toxic compound,which demonstrates that O-chitosan quaternary ammonium derivatives might be a kind of potential medical material.