Design And Properties Of Cationic Antibacterial Polymer

The emergence of "super bacteria" and drug-resistant bacteria poses a serious threat to human health.More and more attention has been paid to develop highly efficient and non-resistant antimicrobial drugs or materials.Cationic antibacterial polymer materials are a kind of polymer materials with antibacterial and sterilizing functions.The antibacterial mechanism of cationic polymer mainly includes: cationic functional groups adsorb the negative charge surface of bacteria rely on coulomb force,the alkyl chains insert into the phospholipid double molecular layer,assisting the destruction of bacterial membrane structure and eventually kill bacteria.However,the chemical structure of cationic antibacterial polymers,such as the molecular structure of the cationic group,molecular weight and distribution,as well as the different chain skeleton types(side chain/main chain),on the effect of the antibacterial properties has not been systematically reported.Based on the designability of the cationic polymeric antibacterial materials,the relationship between the chemical structure and the antibacterial properties of cationic antibacterial polymers is mainly studied in this work.The main research contents and conclusions are as follows:(1)Design and synthesis of pyrrolidinium-type poly(ionic liquid)s antibacterial materials.Studying the antibacterial properties of pyrrolidinium-type small molecule ionic liquids(ILs),poly(ionic liquid)s(PILs),and corresponding PIL membranes with different alkyl chain length.The results of the study are as follows: the antibacterial activity of pyrrolidinium-type ionic liquids and corresponding homopolymers increased with the increase of the alkyl chain length.However,the antibacterial property of the pyrrolidinium-type poly(ionic liquid)membranes decreased with the increase of the length of the alkyl chain.In addition,the prepared poly(ionic liquid)membranes are with good biocompatibility.(2)Molecular structure and antibacterial properties study of side-chain/main-chain cationic polymeric materials.A series of imidazolium(Im),quaternary ammonium(Qa),and 1,4-diazabicyclo[2.2.2]octane-1,4-diium(DABCO-diium)cation-based small molecule cationic compounds and their corresponding side-chain/main-chain cationic polymers were synthesized.The effects of cationic structure,molecular weight and distribution,side chain/main chain types on the antibacterial properties were systematically studied.The results of the study are as follows: 1)The antibacterial activity of side-chain cationic polymers increases with the increase of molecular weight.2)The antibacterial activity of the main-chain cationic polymers are higher than that of corresponding side-chain cationic polymers with similar and even higher molecular weight.3)The antibacterial activity of the synthesized antibacterial compounds decreased in the order: main-chain cationic polymers > side-chain cationic polymers > small molecule cationic compounds.4)The biocompatibility of the side-chain and main-chain cationic polymers was evaluated by testing their hemolysis activities towards human erythrocytes.