Hydrogel, as three-dimensional networks with high water content, has emerged a new wound dressing material in the last decade [1], [2]. In comparison to the traditional dressings, the excellent hydrophilicity of hydrogels not only helps maintain cell hydration in a moist environment, but also aids in absorbing wound exudates, thereby facilitating the healing process [3], [4]. Moreover, precisely designed hydrogels with porous structures can mimic the compositions of natural extracellular matrix (ECM), leading to promoted cell adhesion, proliferation, and differentiation [5], [6]. Until now, various materials have been used to construct functional hydrogels, including carbohydrates [7], [8], [9], proteins [10], [11], [12], and synthetic polymers [13], [14], through chemical or physical interactions. In addition, a new type of intelligent hydrogels has been designed using supramolecular or dynamic covalent bonding, leading to functional materials with self-healing and responsive characteristics [15], [16], [17], [18]. Nevertheless, many wound dressing hydrogels still require additional encapsulation of bioactive compounds or drugs to enhance anti-inflammatory, anti-oxidative and adhesive properties [19], [20], [21].

Fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) is one of the most widely studied ultra-short peptide. It can be readily self-assembled into self-supporting hydrogels through supramolecular interactions under physiological conditions [22], [23], [24]. Fmoc-FF can also be incorporated into hybrid systems with other entities, such as polysaccharides, polymers and peptides [25], [26]. We have previously reported a novel glycosaminoglycans (GAGs) mimicking nanoparticles/fibers through a hybrid supramolecular co-assembly of Fmoc-FF and sulfated glyco-modified fluorenylmethoxy derivatives (FGS and FG3S) [17]. The obtained nanostructures and the related hydrogels showed excellent promotion effect for cell proliferation through the binding of basic fibroblast growth factor (bFGF), with efficiency comparable to natural heparin. Considering ECM is constituted with a large number of GAGs that facilitate cell adhesion, proliferation and differentiation [27], [28], [29], these GAG-mimicking sulfated glyco-hydrogels also show promise as materials for cell proliferation-featured wound dressing. The addition of polydopamine (PDA) into the hydrogel networks can enhance adhesion and anti-oxidative properties in wound areas. PDA, a bioactive polymer generated from dopamine in oxidizing conditions, efficiently endow adhesiveness to most of the surfaces [30], [31], [32].

In the current work, diphenylalanine-dopamine (FFD) was synthesized first, followed by hybrid incorporation into glycol-based supramolecular systems with Fmoc-FF and FGS (or FG, FG3S), through π–π interaction and β-sheet folding [33]. Upon oxidation of dopamine, hydrogels with dual and interpenetrating networks can be in situ generated, resulting in enhanced mechanical strength, together with the inserted adhesion and anti-oxidation properties [34], [35]. Connected by the non-covalent dynamic linkages, the hydrogels inherent self-healing ability for repairing broken network without any external stimuli [36], [37], [38]. Moreover, the embedding of sulfated N-acetylglucosamine structure into the hydrogel can mimic the structure of natural GAGs, such as heparin, and endow the materials with promotion effects for cell proliferation, migration, and anti-inflammatory activity [17], [39], [40], [41], which are all beneficial to accelerated wound healings.