Polyglutamic Acid‐Based Elastic and Tough Adhesive Patch Promotes Tissue Regeneration through In Situ Macrophage Modulation

Abstract

Adhesive patches are advanced but challenging alternatives to suture, especially in treating fragile internal organs. So far there is no suture‐free adhesive patch based on metabolizable poly(amino acid) materials with excellent mechanical strength as well as immunomodulation functionality. Here, a polyglutamic acid‐based elastic and tough adhesive patch modified by photosensitive groups on the surface to achieve robust light‐activated adhesion and sealing of flexible internal organs is explored. With the porous internal morphology and excellent biodegradability, the patches promote regeneration through a macrophage‐regulating microenvironment. Treated rabbits achieve rapid full‐thickness gastric regeneration with complete functional structure within 14 d, suggesting its robust tissue adhesion and repair‐promoting ability.

Tissue adhesives for wound closure

“…In a rabbit gastric perforation model, LAP can be used for sutureless wound closure and total gastric repair. The progress made in this study will demonstrate next-generation adhesive patches with mechanical abilities and macrophage modulation capabilities 105 (Figure 7B).…”

Recent developments in stimuli‐responsive hydrogels for biomedical applications

“…The photogenerated thiol and nitroso groups rapidly underwent non‐radical crosslinking via S‐nitrosylation to form a thin gel in less than 5 s, and the generated aldehyde groups interacted with the amino groups on the tissue to achieve in situ adhesion (Figure 9a). In another study, a biocompatible light‐controlled adhesive patch (LAP) was designed, which consisted of three parts: a highly absorbent matrix hydrogel composed of polypeptides, an adhesive surface modified with NB groups, and a base film prepared with poly(L‐lactic acid) to enhance the mechanical strength of the patch [66]. The photoactivated LAP was then applied as a wound dressing that could quickly and firmly seal open wounds in multiple viscera (Figure 9b).…”

“… (a) Preparation process of the cyclic o‐nitrobenzyl‐modified hyaluronic acid (HA‐CNB) hydrogel‐based adhesive [65]; (b) Light‐controlled adhesive patch (LAP) promotes skin wound healing after UV irradiation [66]; (c) Schematic representation of the in situ imine crosslinking‐based photo‐responsive chitosan (NB‐CMC/CMC) hydrogel achieving wet adhesion after UV irradiation [67]. CMC, carboxymethyl chitosan; NB, o‐nitrobenzyl alcohol.…”

Enhancing the interfacial binding strength between modular stretchable electronic components

“…Adapted with permission from Ref. [ 88 ]. (E) Dopamine adhesive and gelatin microgel-based tissue adhesives.…”

“…For example, an adhesive patch could be light-activated to covalently bond to tissues via photo conversion from o-nitrobenzene to o-nitrosobenzaldehyde groups and subsequent formation of Schiff base with amine groups on tissue surfaces (Fig. 7D ) [ 88 ]. Dopamine groups have also been utilized to covalently bond to tissues [ 89 , 90 ].…”