Mucus-Inspired Supramolecular Adhesives: Exploring the Synergy between Dynamic Networks and Functional Liquids

Abstract

The exceptional physicochemical and mechanical properties of mucus have inspired the development of dynamic mucus-based materials for a wide range of applications. Mucus's combination of noncovalent interactions and rich liquid phases confer a range of properties. This perspective explores the synergy between dynamic networks and functional liquids in mucus-inspired supramolecular adhesives. It delves into the biological principles underlying mucus's dynamic regulation and adhesive properties, the fundamentals of supramolecular adhesive design, and the transformative potential of these materials in biomedical applications. Finally, this perspective proposes potential directions for the molecular engineering of mucus-inspired supramolecular materials, emphasizing the need for interdisciplinary approaches to harness their full potential for biomedical and sustainable applications.

Keywords: bioinspired material; gel; hydrogen bond; micro/nanochannel; mucus; supramolecular polymer; wearable sensor.

Figure 1

Inspired by viscoelastic mucus in different creatures, supramolecular adhesives can utilize various noncovalent interactions to develop the required properties. One supramolecular interaction or multiple supramolecular interactions can be introduced to one adhesive system. Optical images of a mussel, sandcastle worm, and snail are produced with a completely free Cici-AI photographer. The mussel-inspired structure (a dopamine-modified supramolecular adhesive) is adapted with permission under a Creative Commons License from ref (30). Copyright 2017 Springer Nature. The snail-inspired structure (an intrinsically reversible polymeric superglue) is adapted with permission from ref (23). Copyright 2019 National Academy of Sciences.

Figure 2

(A) Mucus is usually located in the eyes, lungs, and digestive system. It can work as a lubricant and protective barrier with both passive physical isolation and active antibacterial mechanisms. In addition, it offers the selective trans-mucus delivery of needed lipopolysaccharide (LPS) and ions. (B) The mucus is constructed from highly dynamic three-dimensional networks comprising water, mucins, globular proteins, and various ions, which are assembled together through abundant supramolecular interactions such as hydrogen bonding, electrostatic interactions, hydrophobic interactions, physical cross-linking, and van der Waals forces.

Figure 3

Different reversible bonds can be introduced in designing supramolecular adhesives. Reproduced with permission from ref (51). Copyright 2024 John Wiley and Sons.

Figure 4

(A) Chemical structures of the thiol-functionalized polymers and catechol-functionalized polymers for the mucin-inspired adhesives are reprinted with the authors’ permission from ref (79). Copyright 2025, the Author(s). (B) Schematic diagram for the preparation, adhesion, advantages, and applications of the sustainable snail-inspired organic solvent-free adhesives. Reproduced with permission from ref (80). Copyright 2024 John Wiley and Sons.

Figure 5

(A) Polyurea oligomers and (B) semicrystalline polymer were used to assemble with carvacrol oils for preparing different supramolecular antimicrobial organogel adhesives. Reproduced with permission from refs (74) and (87). Copyright 2020 and 2023 American Chemical Society. (C) Supramolecular slippery organogels demonstrated persistent fouling-release and damage-healing properties. (D) Antibacterial properties were enhanced by localized molecular controlled release with the wrapping layer. Reproduced with permission from ref (84). Copyright 2021 John Wiley and Sons.

Figure 6

Schematics show that a velvet worm excretes mucus to capture prey, in which the mucus will be transformed from the soft state into a stiffened state when it contacts the prey. Inspired by the secretions, the adhesive robot was designed with a reversible magnetorheological effect to operate a tumor removal surgery. Adapted with permission under a Creative Commons License from ref (101). Copyright 2024 American Association for the Advancement of Science.

Figure 7

(A) The constructed conducting polymer hydrogel consisted of a continuous electrical phase and a continuous mechanical phase for applications in the self-adhesive bioelectronic interface. Reproduced with permission from ref (103). Copyright 2023 Springer Nature. (B) A schematic illustration of the microphase-separated bicontinuous ionogel with the capability of multimodal sensation is provided. Reproduced with permission from ref (105). Copyright 2023 John Wiley and Sons. (C) A schematic structure of the ionogel fiber with polymerization-induced bicontinuous phase separation is provided. Reproduced with permission from ref (106). Copyright 2024 John Wiley and Sons.

Figure 8

(A) A supramolecular adhesive was assembled and aggregated by hydrogen-bonded UPy–PEI particulates, showing reversible hydration and dehydration behaviors. (B) The particulate-aggregated adhesive exhibited a sustained release ability for wound disinfection due to the superior adhesive and exudate-sensitive properties on mice wound sites. Reproduced with permission from ref (114). Copyright 2020 American Chemical Society. (C) The LM-enhanced adhesive patch achieved tunable adhesive properties for monitoring electrophysiological signals and promoting wound treatment. (D) The material structure of LM-enhanced UPy–PEI adhesive patch is provided. Reproduced with permission from ref (115). Copyright 2024 John Wiley and Sons.