Plant derived tannic acid-based tissue adhesives: From mechanism to advanced design

Tissue adhesives have emerged as promising alternatives to conventional incision closure techniques, offering minimal invasiveness and improved adaptability to complex tissue environments. Tannic acid (TA) is a plant-derived polyphenol and has gained increasing attention due to its unique chemical structure and versatile bioactivity. With rich phenol groups, TA can form covalent and non-covalent bonds with the functional group on tissue surface, enabling strong interfacial adhesion and reinforcing internal cohesion within hydrogel networks. In addition, TA can simultaneously exhibit antioxidant, antimicrobial, and anti-inflammatory properties, further enriching its biomedical applications. This review summarizes the roles of TA in improving the mechanical and biological performance of tissue adhesives, and introduces its adhesion mechanisms, adhesive designs, and emerging applications. It highlights the methodologies of utilizing TA for multifunctional adhesive designs and challenges for clinical translation, emphasizing its value and complexity as a versatile component for next-generation tissue adhesive development. STATEMENT OF SIGNIFICANCE: Tissue adhesives are emerging as powerful alternatives to connect two surfaces, which have been actively applied on tissue-tissue and tissue-device interfaces. Tannic acid is a plant-derived polyphenol containing catechol and pyrogallol groups, which can reinforce both interfacial adhesion and adhesive cohesion. Notably, tannic acid simultaneously offers multiple biofunctions including antioxidant, antimicrobial, and anti-inflammatory functions, compared with other adhesive moieties. This review introduces the unique polyphenolic structure of tannic acid with its adhesive and biofunctional mechanisms and discusses strategies for tannic acid-incorporated tissue adhesive development. Through the combination of strong adhesion and intrinsic bioactive properties, tannic acid-based adhesives enable attractive incision closure, tissue repair, and device attachment, advancing their clinical translation.