From Adhesion to Detachment: Strategies to Design Tissue-Adhesive Hydrogels

The use of tissue adhesives dates to 1940s when surgical glues were introduced for wound closure applications. However, current clinically used tissue adhesives (fibrin and cyanoacrylate glues) have limited adhesion strength and biocompatibility issues which restrict their performance in targeted applications. Due to this unmet clinical challenge, there is a need to develop next-generation tissue adhesives to expand the current limited available options. Another factor that is often overlooked in the field is the consequence of when these tissue adhesives fail while in use in specific applications. In this review, the complications arising from tissue adhesives that have insufficient adhesion strength are covered, where unintentional loosening and detachment can lead to serious complications depending on both the applications and scenarios in which the adhesives are used. Next, the current methodologies employed to design tissue-adhesive hydrogels targeting specific applications are also collated. Finally, the different strategies to engineer on-demand removal property of these tissue-adhesive hydrogels are consolidated, including some perspectives on current challenges and outlooks in this field.