writer：Guo Li,* Youpeng Wang, Shuwei Wang, and Jinqiang Jiang*
keywords：composite hydrogel, controlled release, hydrophobic drug, poly(vinyl alcohol), ultrasound
source：期刊
Issue time：2018年

Developing wound dressings that have strong adhesion strength without

causing any conglutination to the wound site is still challenging. Herein,

is proposed that zwitterionic shape memory polymers can be applied as

promising candidates for wound dressing. Sulfobetaine methacrylate (SBMA)

is copolymerized with 2,3-dihydroxypropyl methacrylate (DHMA) in the presence

of boric acid as a cross-linking agent. The prepared material exhibits

multi-stimuli responsive shape memory behaviors: it can rapidly return to its

initial shape upon heating to 90 °C, and a gradual recovery is also observed

by absorbing moisture in humid environments. The shape memory effect can

be well adjusted via incorporation of sodium chloride to induce the dissociation

of electrostatic interactions between PSBMA chains, leading to reduced

transition temperature and faster shape recovery rate. Moreover, the dynamic

nature of boron ester bonds and electrostatic interaction endows the material

with effective and rapid self-healing ability. It is also demonstrated that the

deployment process of the dressing that a sample with an initially circular

shape can perfectly fit and tightly bind to the wound site after moistureinduced

shape recovery. The proposed zwitterionic polymer can possibly

extend the application scope of shape memory polymers and pave a new way

for the design of wound dressings.