title: Synthesis, self-assembly, and cytotoxicity of well-defined trimethylated chitosan-O-poly(ε-caprolactone): effect of chitosan molecular weight.
abstract: Structurally well-defined trimethylated chitosan-O-poly(ε-caprolactone) (TMC-O-PCL) was synthesized under mild homogeneous conditions, using sodium dodecyl sulfate-dimethylated chitosan complex (SDC) as an organosoluble intermediate. The effect of chitosan molecular weight (MW) on the preparation, organosolubility, self-assembly, and cytotoxicity of the copolymers was investigated. The copolymers with low-MW chitosan backbone had improved solubility in common organic solvents. Spherical micelles with average diameter of 25-55 nm and uniform morphology were formed through self-assembly of TMC-O-PCL in pH 7.4 PBS. When trimethylation degree of the copolymers was above 44%, the micelles could remain stable in neutral aqueous media. The critical aggregation concentration of TMC-O-PCL slightly increased with a decrease in the MW of chitosan backbone. The cytotoxicity of the cationic micelles could be suppressed by increasing PCL grafting levels, reducing trimethylation degree, and MW of the chitosan backbone.
authors: Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors: Haiwen
authors: H
authors: Zhang
authors: Guoqiang
authors: G
authors: Cai
authors: Guping
authors: G
authors: Tang
authors: Liqun
authors: L
authors: Wang
authors: Hongliang
authors: H
authors: Jiang