文献类型：会议论文

英文题名：Copolymerization of Chitosan Selectively Grafted by Polyethylene Glycol as DNA Delivery Vectors

作者：Li Ruo-hui[1]; Xie Fei[1]; Cheng Yan-ling[1]; Shan Dan-tong[1]

第一作者：李若慧

机构：[1] Biochem. Eng. Coll., Beijing Union Univ., Beijing, China

第一机构：北京联合大学生物化学工程学院

会议日期：28-30 May 2012

会议地点：Macao, China

语种：英文

外文关键词：biochemistry - bio-optics - condensation - DNA - infrared spectra - molecular biophysics - polymer blends - polymerisation - sugar - suspensions - swelling

摘要：Co polymerization of chitosan selectively grafted by polyethylene glycol was studied in this paper. The graft copolymers can be expected to be used as DNA delivery vectors because of the improving hydrophilicity of chitosan and reserving the amino groups on chitosan chains. Chitosan was selectively grafted by monomethoxy polyethylene glycol(mPEG-OH), which contains a hydroxyl group combining with hexamethylene diisocyanate(HDI) to form a novel macro monomer namely monomethoxy polyethylene glycol isocyanate (mPEG-NCO) containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted co polymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG-NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling level in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.