Dongdong Lu

A single chemically tailored hydrogel encodes three orthogonal outputs including swelling, transparency, and conductivity, for machine-learning-assisted discrimination of tastes, monosaccharides, and chiral isomers.

Microgel-introduced B-N coordination-mediated hydrogels were fabricated by in situ copolymerizing acrylamide (AAm) within phenylboronic acid-functionalized microgel (MG(APBA)) dispersions. The dynamic energy-dissipation mechanisms arise from topological entanglements, reversible B-N coordination, multiple hydrogen bonds, and hydrophobic interactions, enabling the formation of robust networks without additional chemical cross-linkers. By tuning MG(APBA) and AAm concentrations and adjusting pH, the mechanical properties were precisely optimized. The optimized hydrogel 4MG(APBA)-35PAAm (pH 7.4) exhibits a tensile strength (452.1 kPa), a fracture strain (2400%), a toughness (4075.7 kJ/m³), ultralow hysteresis, and outstanding fatigue resistance. CNT incorporation provides sensitive electromechanical responses, with a gauge factor (GF) of 7.25, pressure sensitivity of 1.65 kPa^-1, and stable cycling over 500 cycles. The hydrogels are cytocompatible and enable real-time motion sensing and force mapping. This work demonstrates that microgel reinforcement and synergistic dynamic interactions markedly enhance the mechanical and sensing performance of hydrogels.

Self-monitoring, functional, injectable hydrogels represent an advancement in smart biomaterials. In this study, we developed injectable dual-responsive hydrogel composites with near-infrared (NIR) emission, fabricated from a nonradiative energy transfer (NRET) nanoprobes and doubly cross-linked microgel (DX MG) building blocks. These hydrogels were easily prepared and exhibit reversible responsiveness to both pH (4.5-7.4) and Ca²⁺ (0.005-0.08 M) through phototriggered covalent cross-linking of low-concentration (∼7 wt %) shear-thinning microgels. The resulting gels demonstrate tunable modulus and swelling ratios in response to environmental pH and Ca²⁺ levels, which could be reversibly monitored via NIR ratiometric photoluminescence (RMPL). They withstood 90% compression with low hysteresis, enabling NIR-monitored cyclic compression and tissue imaging. A bilayer actuator, combining DX MG with green-emitting polyacrylamide gels, achieved simultaneous pH/Ca²⁺ response and tortuosity monitoring via NIR RMPL. To the best of our knowledge, this is the first report of a self-monitoring hydrogel actuator utilizing NIR ratiometric photoluminescence, offering significant promise for PL bionic-driven soft matter and biomedical applications.

The skin is fragile, making it very vulnerable to damage and injury. Untreated skin wounds can pose a serious threat to human health. Three-dimensional polymer network hydrogels have broad application prospects in skin wound dressings due to their unique properties and structure. The therapeutic effect of traditional hydrogels is limited, while multifunctional composite hydrogels show greater potential. Multifunctional hydrogels can regulate wound moisture through formula adjustment. Moreover, hydrogels can be combined with bioactive ingredients to improve their performance in wound healing applications. Stimulus-responsive hydrogels can respond specifically to the wound environment and meet the needs of different wound healing stages. This review summarizes the material types, structure, properties, design considerations, and formulation strategies for multifunctional hydrogel composite dressings used in wound healing. We discuss various types of recently developed hydrogel dressings, highlights the importance of tailoring their physicochemical properties, and addresses potential challenges in preparing multifunctional hydrogel wound dressings.

A minireview focusing on OECTs for biosensors and bioelectronics applications, highlighting gel electrolytes as effective strategies for enhancing flexibility, adhesiveness, self-healing ability, biocompatibility, and long-term stability of OECTs.

A conductive double-network polyelectrolyte hydrogel with multiple interactions was developed. The gel is stretchable, self-adhesive, and transparency adjustable. It can be applied to flexible bioelectronic sensing and information encryption.