Advances in Biomedical and Environmental Applications of Magnetic Hydrogels

Hydrogels have been the focus of research across disciplines or subject perspectives owing to their distinctive chemical, physical, and mechanical characteristics. Hydrogels have been leveraged for their biocompatibility and attractive adhesion or adsorption behavior. Conventional hydrogels suffer from frequent entrapment due to low controllability, limited responsiveness, and weak actuation properties. Magnetic hydrogels address many of these concerns and offer a rapid magnetic response and precise temporal and spatial control. The structural and functional features of magnetic hydrogels can address overlapping requirements in biomedical and environmental applications. The focus of this review is on the progress made in the use of magnetic hydrogels. Specifically, their applications in controlled drug delivery as contrast agents in magnetic resonance imaging and in the treatment and remediation of wastewater are discussed. The first part of the review delineates strategies for preparing magnetic hydrogels and the advantages of each approach. The second part of the review describes a variety of biomedical and environmental applications for highlighting the convergent functionalities of magnetic hydrogels that are relevant to each domain. The challenges in the use of magnetic hydrogels and prospective applications are also included in the review.