A Thermo‐ and Moisture‐Responsive Zwitterionic Shape Memory Polymer for Novel Self‐Healable Wound Dressing Applications

Abstract

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 moisture‐induced 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.

A comprehensive review of the structures and properties of ionic polymeric materials

“…136 Li et al also reported a water-triggered shape-memory behavior for a zwitterionic polymer. 137 Again, moisture absorption led to breaking of ionic interactions and a plasticizing effect, which allows an improved strain release and recovery to the permanent shape.…”

“…144 It is worth mentioning that moisture can act as a local plasticizer at the cut surfaces, increasing local mobility and liberating free ionic groups to heal local damage. 137 For instance, Wen et al designed zwitterionic PU bearing pyridinium and sulfonate moieties. 148 Within such systems, a high zwitterion amount led to higher self-healing performance (from ca.…”

“…Likewise, Li et al presented self-healing zwitterionic-based polymethacrylate and reported the influence of salt on healing efficiency. 137 Adding NaCl salt increased the ionic exchange rate, which in turn led to higher strain at break after self-healing treatment due to destabilization of the polyion complex, also called an antipolyelectrolyte effect. This effect may not be an improvement of steady-state healing but rather a faster healing process due to an increased exchange probability with the polymer and salts.…”

Wound Healing: From Passive to Smart Dressings

“…fabricated a copolymerized novel zwitterionic shape memory polymer composed of sulfobetaine methacrylate (SBMA) and diol acrylate monomer (dihydroxypropyl methacrylate, DHMA) for wound healing applications. [ 50 ] In this report, boric acid was added as crosslinkers to the polymeric complex. Shape memory behavior for this hydrogel dressing was created from electrostatic interactions of PSBMA chains with dynamically bonded boron esters, which are triggered by either temperature or absorbing moisture.…”

Intelligent Polymers, Fibers and Applications

“…Mater. Interfaces 2019 , 11 (35), 32408–32413, Copyright American Chemical Society) [ 54 ]; ( d ) thermal- and humidity-triggered response of zwitterionic SMP [ 61 ].…”