An Adhesive/Anti‐Adhesive Janus Tissue Patch for Efficient Closure of Bleeding Tissue with Inhibited Postoperative Adhesion

Abstract

Most of the current bioadhesives cannot perform well on bleeding tissues while postoperative adhesion is a general but serious clinical issue. Here, a three‐layer biodegradable Janus tissue patch (J‐TP) that is able to simultaneously enable efficient closure of bleeding wounds with significantly promoted clotting ability and suppressed postoperative adhesion of tissues is reported. A dry adhesive hydrogel bottom layer of the J‐TP can form rapid (within 15 s) and strong (tensile strength up to 98 kPa) adhesion to bleeding/wet tissues with high bursting pressure (about 312.5 mmHg on a sealed porcine skin) through hydrogen binding and covalent conjugation between the carboxyl & N‐hydroxy succinimide (NHS) groups of hydrogel and the primary amine groups of tissues, while the phosphonic motifs can significantly reduce blood loss (by 81% on a rat bleeding liver model) of bleeding wounds. A thin polylactic acid (PLA) middle layer can improve the tensile strength (by 132%) of the J‐TP in wet conditions while the grafted zwitterionic polymers can effectively prevent postoperative tissue adhesion and inflammatory reaction. This J‐TP may be a promising tissue patch to assist the clinical treatment of injured bleeding tissues with inhibited postoperative adhesion.

Hemoadhican-Based Bioabsorbable Hydrogel for Preventing Postoperative Adhesions

“…Janus hydrogels typically rely on hydrogen bonding, covalent cross-linking, and water-removal adhesion mechanisms to achieve wet adhesion. Various strategies, such as unilateral ion sealing, solvent immersion, and hydration, have been utilized to achieve asymmetric tissue adhesion. , …”

“…Various strategies, such as unilateral ion sealing, solvent immersion, and hydration, have been utilized to achieve asymmetric tissue adhesion. 79,80 HD has been proven to rapidly absorb small quantities of blood, firmly adhere to injured tissues through a repel-crosslinking mechanism, and not trigger extra inflammatory reactions, making it advantageous for treating surgical wounds with bleeding. 40 The plentiful branched chain structures of HD help it form a brush-like conformation on hydrogel surfaces, resulting in significant antifouling properties.…”

Janus Polyurethane Adhesive Patch with Antibacterial Properties for Wound Healing

“…The closure of injured tissue is a key step in reconstructing its structure and function. , Currently, surgical suture/nail are mainly used to close the wound and surgical incision. − However, suturing may cause damage to fragile tissues, increase the risk of bacterial infection, and be time-consuming and technically demanding. − Medical tissue adhesives are expected to become an auxiliary or alternative to traditional surgical sutures. − However, existing tissue adhesives usually fail to achieve the desired effect, with poor adhesion properties (fibrin glue), , poor stability (mussel-inspired adhesive, N -hydrosuccinimide ester), , and causing allergies (acrylate adhesive). , More importantly, most tissue adhesives are indiscriminate double-sided adhesions, which makes them easy to adhere to normal tissues and causes postoperative hidden trouble. − Additionally, the back of double-sided adhesive is easy to adhere to various substrates in the environment, which will increase the risk of wound microbial infection and inconvenience. These limitations significantly hinder the application of traditional double-sided bioadhesives in tissue repair and clinical practice. , …”

A bioinspired injectable antioxidant hydrogel for prevention of postoperative adhesion

“…56,57 However, consideration of oxidative stress and free radicals in wound healing is lacking in most hydrogels used for anti-adhesion purposes. 58–60 Requisite control over the production of free radicals is imperative to mitigate tissue adhesion. 61…”