Body-responsive shape-memory polymers for biomedical applications

Shape memory polymers (SMPs) have emerged as versatile and adaptive materials in healthcare, offering transformative solutions for tissue repair and biomedical device interfaces. Their ability to undergo controlled shape changes in response to external stimuli has driven significant interest in developing smart implants for minimally invasive procedures. Precise material design and engineering that leverage physiological conditions, such as body temperature and bodily fluids, can unlock their potential for biomedical applications. This review focuses explicitly on SMPs activated by physiological stimuli, referred to here as "body-responsive" SMPs. By categorizing SMPs into temperature-responsive, water-responsive, and dual-responsive variants, their shape memory behavior is analyzed, with an emphasis on how the structural design governs the body-responsiveness of the SMPs. Current biomedical applications, including tissue engineering, vascular interventions, bioelectronic devices, and targeted drug delivery, are also highlighted to demonstrate the practical relevance and versatility of body-responsive SMPs. Additionally, emerging fabrication technologies are discussed to provide insight into current scalable production methods suitable for SMPs. Finally, challenges in the design and performance of SMPs are explored, and a vision for future advancements is presented, outlining a roadmap for translating SMPs into biomedical applications within clinical settings.