Multi-stimuli-responsive hydrogels and their medical applications

Abstract

The functionality of multi-stimuli-responsive hydrogels in physiological states is the reason for the increased attention of hydrogels nowadays. Multi-stimuli-responsive hydrogels exhibit tunable changes in swelling or mechanical properties in response to predetermined combinations of stimuli such as pH, temperature, ionic strength, electric field, magnetic field, light, chemical triggers, enzyme concentration, redox species, reactive oxygen species (ROS), and glucose levels. This review summarizes the recent advances in multi-stimuli-responsive hydrogels used in medical approaches. The first part of the review highlights the medical applications of polymer-based and supramolecular hydrogels and emphasizes the priority of multi-stimuli hydrogels over single-stimuli hydrogels. Also, recent studies in medical applications of multi-stimuli-responsive hydrogels are collected with a focus on self-healing hydrogels, anti-bacterial materials, and drug-delivery systems.