Injectable hydrogel adhesives for surgery: Design, cross-linking strategies, and applications

• Sutures and anastomoses may cause incomplete sealing and secondary tissue damage • Non-invasive hydrogels show considerable potential as medical adhesives • Injectable hydrogel adhesives boast of convenience and complete wound coverage • Key advantages include the gel formation time, safety, and swelling ability • Common design strategies include chemical and physical cross-linking and biomimicry Sutures and anastomoses are widely used for surgical closure; however, owing to their high technical requirements, operation complexity, and limitations of the methods themselves, both closure methods can result in incomplete sealing, causing secondary tissue damage. In recent years, non-invasive hydrogels have demonstrated considerable potential as medical adhesives for applications such as tissue regeneration, wound closure, and wound repair, owing to their superior biological properties and ease of operation. Among them, injectable hydrogel adhesives have attracted increasing attention in the surgical field for their handling convenience and ability to provide complete wound coverage. However, to date, no comprehensive reviews of their use in surgery have been reported. Consequently, we review progress in the design of injectable hydrogels over the past decade, including their design principles, cross-linking strategies, and evaluation methods. We also highlight their application in different surgical fields—including neurosurgery, ophthalmology, cardiothoracic surgery, general surgery, urology, plastic surgery, and orthopedic surgery. In this review, we aim to provide meaningful insights into the design of next-generation hydrogel adhesives for wound closure and tissue regeneration. In recent years, non-invasive hydrogels have demonstrated considerable potential as medical adhesives for applications such as tissue regeneration, wound closure, and wound repair, owing to their superior biological properties and ease of operation. Among them, injectable hydrogel adhesives have attracted increasing attention in the surgical field for their handling convenience and ability to provide complete wound coverage. Consequently, this paper reviews progress in the design of injectable hydrogels over the past decade, including their design principles, cross-linking strategies, and evaluation methods. It also highlights their application in different surgical fields—including neurosurgery, ophthalmology, cardiothoracic surgery, general surgery, urology, plastic surgery, and orthopedic surgery.