Adhesive Hydrogels: Design, Fabrication, and Bio-applications

Abstract

In recent years, adhesive hydrogels have gained increasing attention as emerging biomedical materials due to high demand for fundamental research and practical biomedical applications, because tissue adhesiveness enables integration with surrounding tissues. Recently, adhesive hydrogels have been used in many areas of biomedicine, such as implant scaffolds in tissue engineering, mucosal adhesives to extend the administration site time, and bio-adhesives in place of seam needles to reduce infection. The tissue-adhesion ability of hydrogels are governed by adhesion and cohesion. Adhesion is the bond generated between hydrogels and tissue surfaces. Cohesion is the internal strength that holds the hydrogel network together and determines the mechanical strength of the materials. Adhesive hydrogels require sufficient cohesion to allow the typical extrusion, contraction, and expansion of tissues. In addition, high adhesion and cohesion prevent hydrogels from detaching during hemostasis or occlusion or from being damaged by fast-flowing fluids (such as blood). Despite impressive progress in adhesive hydrogels for biomedical applications, there are a number of unanswered questions in this line of research. For example, how can smart adhesive hydrogels be developed for specific biomedical purposes, such as reversible adhesion? How to control the toxicity of adhesive hydrogel in the body? How can wet adhesion be achieved, especially in the moist environment of the mouth and stomach? How to prevent adhesion with other normal tissues? How to provide the hydrogel with multifunctions, such as self-healing and strong mechanical strength. We welcome researchers to submit articles (original research, reviews, mini-reviews, and perspective articles). Possible topics include, but are not limited to: • Design and preparation of bioadaptability adhesive hydrogel • Adhesive hydrogel for anti-bacteria/biofilm/infection • Adhesive hydrogel for fast hemostasis • Adhesive hydrogel for tissue repair and regeneration • The underlying mechanisms and interactions between adhesive hydrogel and cell/tissue/organ • Toxicology evaluation on adhesive hydrogel • Application of adhesive hydrogel in wearable electronic devices