Stimuli-Responsive Polymers: Principles, Design Strategies, and Emerging Biomedical Applications

Abstract

Stimuli-responsive polymers (SRPs) are emerging materials in biomaterials research and have been recognized as an innovation in biomaterials due to their dynamic nature, which cannot be obtained by conventional passively reactive materials. This review offers an extensive overview of SRPs ranging from fundamentals of their responses to recent advancements in medical applications. Stimuli-responsive polymers are first classified into physical, chemical, and biological responses depending on their external trigger, such as temperature, light, pH, enzymes, and so forth, followed by explanation of the underlying mechanism in terms of molecular design and structure. Current developments of multiple stimuli-responses, 4D printing technologies, and sustainable synthetic approaches are carefully discussed. Finally, we summarize the biomedical applications such as targeted drug delivery, tissue engineering scaffolds, biosensor, and theranostics with their advantages and challenges. Even though significant progress has been made, various problems remain unresolved such as biocompatibility and sustainability issues. This review ends with future directions such as artificial intelligence-based material designing and bioinspired materials development.