Recent advances in stimuli-responsive hydrogels for food, biomedical, and tissue engineering applications
Stimuli-responsive hydrogels are hydrophilic, three-dimensional polymer network structures that dynamically adjust their properties in response to changes in their external environment, such as temperature, pH, light, electric and magnetic fields, and enzymes. The ease of tuning their physicochemical properties and network architecture gives them an advantage over conventional hydrogels in various applications. This review provides an overview of recent advances in stimuli-responsive hydrogels and critically discusses developments in tissue engineering, food technology, wound healing, controlled drug delivery, and regenerative medicine. Representative examples demonstrate how responsive hydrogel systems can improve cell delivery, tissue regeneration, active food packaging, targeted nutrient release, and infection control. In addition, we also cover a section on the role of neutron scattering techniques, including small-angle neutron scattering (SANS), neutron reflectivity (NR), and quasi-elastic neutron scattering (QENS), in elucidating the network structure of hydrogels, interfacial properties, and molecular dynamics across multiple length and time scales. Finally, current challenges related to scalability, biocompatibility, regulatory approval, and commercialization are discussed, along with future perspectives on translating smart and self-healing hydrogel technologies into practical applications in food, biomedical, and tissue engineering.