title: Hydrogels assembled from star-shaped polypeptides with a dendrimer as the core.
abstract: A second or fourth generation dendrimer with primary amine as the peripheral terminal group was first synthesized via Michael addition and thiol-yne addition. A series of star-shaped polypeptides was synthesized by ring opening polymerization (ROP) of γ-(2-(2-methoxyethoxy)ethyl) l-glutamate (l-EG2Glu) N-carboxyanhydride (NCA) using the amine group terminated dendrimer as the initiator. Taking advantage of the well-defined dendrimer and ROP, the arm number and arm length can be easily controlled. These star-shaped poly(l-EG2Glu) can spontaneously form hydrogels instead of micelles in water at low concentration. The critical gelation concentration (CGC) and hydrogel strength displayed a stronger dependence on arm numbers than the arm length under similar conditions. These properties can be easily modulated by varying the poly(l-EG2Glu) arm length and arm number. The hydrogels showed shear thinning and rapid recovery properties. TEM and AFM characterization revealed that the hydrogel networks were constituted by entangled and branched fibrils.
authors.affiliation: Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. zbli@iccas.ac.cn.
authors.forename: Yong
authors.initials: Y
authors.lastname: Shen
authors.forename: Shusheng
authors.initials: S
authors.lastname: Zhang
authors.forename: Yaoming
authors.initials: Y
authors.lastname: Wan
authors.forename: Wenxin
authors.initials: W
authors.lastname: Fu
authors.forename: Zhibo
authors.initials: Z
authors.lastname: Li