Anti-swelling hydrogels: from preparation strategies to biomedical applications
Hydrogels are extensively utilized in biomedical fields such as drug delivery, tissue engineering, and wound dressings due to their excellent biocompatibility, high water content, and tunable physicochemical properties. However, conventional hydrogels often undergo uncontrolled swelling in physiological environments, leading to mechanical degradation, structural destabilization, and functional failure, which severely restricts their long-term applicability. Recent advances have focused on developing anti-swelling hydrogels with equilibrium swelling ratios typically below 150%, achieved through strategies including the introduction of hydrophobic interactions, enhancement of cross-linking density, and incorporation of nanocomposite structures. These approaches significantly improve dimensional stability and mechanical integrity under physiological conditions. This review systematically summarizes the common preparation strategies for anti-swelling hydrogels and highlights their latest progress in biomedical applications, including wound dressings, tissue adhesives, and implantable devices. The advantages and future directions, such as smart responsiveness and multifunctional integration, are critically discussed. The review aims to provide theoretical guidance and technical references for the development of next-generation high-performance medical hydrogel materials.