Hydrogel-derived luminescent scaffolds for biomedical applications

As a hierarchical polymeric scaffold swollen by a high content of water, hydrogels are transparent, stretchable, dynamic, ionic, and biologically friendly materials that can transmit optical, mechanical, chemical, and electrical signals, thus stimulating enormous opportunities at the interface of soft living matter and machines. In this review, we discuss hydrogel-derived luminescent materials and their biomedical applications associated with the chemistry of the materials. We examine how luminescence features can be integrated with highly modifiable hydrogels to extend the frontiers of luminescent materials, and how luminescence-based lighting, sensing, imaging, and actuating technologies can be implemented on hydrogel scaffolds for biomedical use. We also highlight emerging health technologies on the basis of the luminescent hydrogels and discuss the challenges and the future of the field.