The injectable, self-healing G-quadruplex hydrogel constructed in this study integrates a porous architecture, dynamic reversibility, and robust biological functionality, highlighting its promising potential in antibacterial applications.
Abstract
Injectable and self-healing hydrogels hold tremendous promise for biomedical applications; however, synchronously integrating robust mechanical adaptability, excellent cytocompatibility, and intrinsic antibacterial capabilities within a single matrix remains a significant challenge. In this study, we engineered an injectable, self-healing hydrogel based on dynamic cross-linking using guanosine-derived G-quadruplex supramolecular self-assembly and 3-aminophenylboronic acid (3-APBA)-mediated dynamic boronate ester. Systematic evaluation of various phenylboronic acid derivatives, GMP concentrations, K+ sources, and 3-APBA levels on gelation behavior yielded an optimized formulation. Scanning electron microscopy revealed that the optimized hydrogel exhibits a continuous, interconnected porous network structure after lyophilization. Thioflavin T fluorescence enhancement assays and circular dichroism spectroscopy further verify the formation of G-quadruplex-related ordered assemblies within the system. Rheological assessments demonstrate elasticity-dominated gel behavior, pronounced shear-thinning characteristics, and reversible structural breakdown and recovery under high and low strain cycles, indicating excellent injectability and self-healing properties. In vitro cytocompatibility evaluations show that the hydrogel possesses favorable cellular compatibility. Further antimicrobial studies reveal excellent in vitro antibacterial activity against Staphylococcus aureus and Escherichia coli. In summary, the injectable, self-healing G-quadruplex hydrogel constructed in this study integrates a porous architecture, dynamic reversibility, and robust biological functionality, highlighting its promising potential in antibacterial applications.
The development of antibacterial hydrogel with stretchable and self-healing properties is an urgent problem in the field of biomedical engineering. Herein, a series of hydrogels with antibacterial activity was successfully fabricated using polyvinyl alcohol (PVA), borax, 4-formylphenyl-β-D-allopyranoside (HLC), 3,3′-dithiobis (propionohydrazide) (DPH) and ionic liquid, 1-aminopropyl-3-methylimidazolium bromide (C3MimNBr). The hydrogels were formed via in situ crosslinking through multiple dynamic covalent bonds, primarily including borate ester bonds, imine bonds and acylhydrazone bonds. A Field Emission Scanning Electron Microscope (FE-SEM) revealed that the formed hydrogels possessed a typical three-dimensional network structure. Notably, the interpenetrating network structure endowed the hydrogels with excellent stretchability and self-healing capability, as demonstrated by their ability to be molded into various shapes and stretched up to five times their original length. Furthermore, the mechanical properties of the hydrogel were affected by the amount of the ionic liquid added. Antibacterial evaluation using the colony counting method showed that the hydrogels exhibited outstanding antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In summary, the multifunctional hydrogels, with favorable stretchability and antibacterial activity, represent promising alternative materials for biomedical engineering applications.
Polysaccharide-based hydrogels with strong tissue adhesion, injectability, and self-healing capability are highly desirable for wound management, yet their performance is often limited by rigid polymer conformations and insufficient interfacial interactions. Here, we report a mussel-inspired, dopamine-grafted curdlan hydrogel (Cur-DA) featuring a predominantly single-helical β-glucan architecture. Cur-DA hydrogels were synthesized under alkaline conditions using ethylene glycol diglycidyl ether (EGDE) as a linker, thereby facilitating regioselective dopamine grafting at the C6 position of curdlan. Spectroscopic analyses (UV-Vis, FTIR, solid-state 13C NMR, XRD, and circular dichroism), together with XPS characterization, confirmed successful dopamine incorporation and a conformational transition from native triple helices to more flexible single helices. With this single-helical architecture and catechol functionalization, Cur-DA formed a nanofibrous, porous network with high water content (>90%), increased swelling capacity, and excellent mechanical compliance. Owing to catechol-mediated interfacial interactions and the mobility of single-helical chains, which likely serve as dynamic "sticky ends," Cur-DA hydrogels exhibited robust tissue adhesion (up to 10.21 kPa), self-healing, and outstanding injectability. In vitro assays indicated excellent hemocompatibility and cytocompatibility. In a murine full-thickness skin wound model, an optimized formulation (Cur-DA3) accelerated wound closure, promoted re-epithelialization, and enhanced collagen deposition without inducing systemic toxicity. This work establishes a conformation-engineering strategy for β-glucan hydrogels and highlights Cur-DA as a promising injectable, adhesive wound dressing.
Dongxue Lu, Tian Xiao, Luna Jiang et al.· ACS Applied Bio Materials· 0 citations
Developing hydrogels that simultaneously combine high mechanical robustness, antifreezing capability, and stable conductivity remains a substantial challenge for flexible sensing materials. Herein, we report a multifunctional conductive rotaxane-crosslinked hydrogel constructed from a γ-cyclodextrin/poly(ethylene glycol) diacrylate (γ-CD/PEGDA) slide-ring crosslinker embedded in a poly(vinyl alcohol) (PVA)/acrylamide (AM)/xanthan gum (XG)/Zn2+ network. The threaded crosslinker introduces movable junctions into the network, allowing stress redistribution through a pulley effect and thereby improving the mechanical performance of the hydrogel. Together with hydrogen bonding, Zn2+ coordination, and the physically crosslinked PVA network, this design generates a robust multicomponent architecture. The optimized hydrogel exhibited a tensile stress of 3.2 MPa, an elongation at break of 254%, and a toughness of 40 MJ m−3, together with high puncture resistance and cyclic stability. The hydrogel also showed a freezing point of −20.59 °C and a low equilibrium swelling ratio in water, indicating favorable antifreezing and antiswelling performance. Owing to interconnected ionic conduction pathways, the material further displayed stable ionic conductivity and reliable strain-sensing behavior over a broad strain range, with rapid response/recovery and effective monitoring of human motion and subtle physiological activities. This work provides a practical strategy for constructing mechanically robust, antifreezing, and conductive hydrogels for wearable sensing and related bioelectronic applications.
Jie Ren, Ziqiong Zhou, Wenjing Zhang et al.· Macromolecules· 0 citations
Zwitterionic hydrogels have attracted considerable attention for protein stabilization, cell encapsulation, and therapeutic delivery owing to their highly hydrated and bioinert nature. Nevertheless, developing injectable zwitterionic hydrogels that can form under mild and cytocompatible conditions remains a major challenge, especially for the delivery of fragile proteins and living cells. This challenge mainly stems from the weak intrinsic intermolecular interactions and limited reactive groups of zwitterionic polymers, which make it difficult to establish stable hydrogel networks without additional molecular modification or external crosslinking. Here, we report an injectable zwitterionic supramacromolecular hydrogel (SSH) formed by the spontaneous assembly of poly(methacryloyloxyethyl sulfobetaine) (PSBMA) and poly(styrenesulfonate) (PSSNa). Molecular dynamics simulations support the involvement of anion‐π interactions in gelation, leading to a self‐healing physically crosslinked network. SSH exhibits injectability, self‐healing behavior, intrinsic antiadhesive properties, and favorable immunocompatibility. The mild gelation process enables efficient cell encapsulation and injection while maintaining high cell viability. In addition, SSH stabilizes and delivers basic fibroblast growth factor (bFGF), resulting in improved therapeutic efficacy in a diabetic wound‐healing model. This work establishes a mild gelation strategy for injectable zwitterionic hydrogels and highlights their potential in biomedical delivery and cell‐based therapies.
Long-lasting, high-strength plugging materials are required for deep profile control in low-permeability fractured reservoirs. In this study, a series of hyperbranched copolymer hydrogels was prepared through an aza-Michael addition-amidation-one-pot end-group coupling strategy. Linear alkylamines were used as cores to synthesize amino-terminated generation 1.0 G broom-shaped hyperbranched macromolecular backbones via a divergent route. The resulting backbones were subsequently crosslinked with linear α,ω-diepoxy-terminated poly(ethylene glycol), affording three structurally well-defined hydrogels, denoted as C2HG, C6HG, and C8HG. Structural and physicochemical characterization showed that all hydrogels possessed interconnected three-dimensional porous networks, good thermal stability, and a lower critical solution temperature of approximately 37 °C. Rheological analysis demonstrated predominantly elastic behavior, with the storage modulus (G′) consistently exceeding the loss modulus (G″), together with pronounced shear-thinning characteristics favorable for injection into deep, low-permeability formations. By varying the alkyl-chain length of the hyperbranched backbone, the balance between environmental tolerance and plugging performance could be effectively regulated. These findings establish a structure–property relationship between backbone hydrophobicity and hydrogel performance and demonstrate that PEG-crosslinked hyperbranched copolymer hydrogels are promising candidates for deep-profile control and water shutoff in high-salinity, low-permeability fractured reservoirs.
Xue Wang, Jun Wang, Gen Li et al.· Gels· 0 citations
Elastomers integrating self-healing capability, recyclability, and excellent mechanical performance have attracted considerable interest owing to their great application prospects in the emerging fields of soft robots, wearable electronics, and biomedical engineering. Herein, we synthesized a tough, self-healing and recyclable polyurea elastomer through the addition reaction of isophorone diisocyanate with polyether amine and 3,5-diaminobenzoic acid, followed by the incorporation of metal ions to construct dual dynamic crosslinked networks composed of multiple hydrogen bonds and metal-carboxylate coordination bonds. Unlike the Fe3+-coordinated polyurea elastomer, the Zn2+-coordinated polyurea elastomer achieved excellent mechanical performance, with a tensile strength of 10.89 MPa, an elongation at break of 1656% and toughness of 137.40 MJ m-3, which was attributed to the moderate coordination capability and homogeneous dispersion of Zn2+ ions, as confirmed by theoretical simulations and polarized light imaging. Benefiting from the formation of the dual dynamic crosslinked networks, the elastomer demonstrated superior self-healing capability with a healing efficiency of 93.5% at 60 °C for 24 h and remarkable recyclability through hot-press and solvent recycling methods with tensile strength retentions of 80.0% and 99.3% after three recycling cycles, respectively. In addition, a polyurea-elastomer-based tubular flexible strain sensor with liquid metal as a conductive substance for object recognition was highly sensitive, completely recyclable, and capable of self-healing. The findings in this work conceivably represent a new methodology for the preparation of high-performance, functional and sustainable elastomers and flexible sensors.
Yi-Xuan Guo, Jingzhi Tang, Zhipeng Yang et al.· Materials Horizons· 0 citations