Advances in Hydrogel Film Fabrication and Functional Applications Across Biomedical and Environmental Fields

Hydrogel films are a promising class of materials due to their peculiar property of retaining water as well as responding to external stimuli. In contrast with conventional hydrogels, films provide enhanced responsiveness along with greater compliance to be integrated into devices as well as on surfaces. This review is designed to comprehensively explore the many aspects of hydrogel films. It covers the principles of gelation; preparation methods, such as solvent casting, spin coating, and photolithography; and characterization. This review also presents the most common polymers (both natural and synthetic) utilized for the preparation of the hydrogel, the systems, such as nanoparticles, liposomes and hybrid metal–organic structure, that can be used as additives and the aspects related to the biocompatibility of hydrogels. In the second part, this review discusses the potential applications of hydrogel films and the challenges that still need to be overcome. Particular attention is given to biomedical applications, such as drug delivery, wound healing, and tissue engineering, but environmental and agricultural uses are also explored. Finally, this review presents recent examples of real-world applications of hydrogel films and explores the possibility they have for a wide variety of needs.