Xin Zhao

Interfacial hydration fundamentally constrains adhesion in aqueous and physiological environments by preventing intimate contact, competing for binding sites, and weakening the load-bearing interfaces. Although wet adhesives have been extensively designed for durable fixation, emerging technologies in soft robotics, wearable bioelectronics, and minimally invasive medicine require interfaces that can form adhesion, recover after reuse, or detach on-demand under hydrated conditions. This Review discusses reversible wet adhesion through two operational modes: Mode I, cyclic reusability through repeated restoration of adhesion over attachment-detachment cycles, and Mode II, on-demand detachability through trigger-induced conversion of a stable adhesive state into a weakly adherent state through a controlled, low-damage release pathway. We examine supramolecular interactions, dynamic covalent chemistry, mesoscale architectures, biomimetic designs, and hybrid strategies as complementary routes for regulating hydration, interfacial binding, mechanical dissipation, and adhesive state transitions at wet interfaces. We analyze how contact formation, hydration history, fracture pathways, loading history, test geometry, and biofluid exposure shape the measured performance. We further assess current methods for quantifying reusability, switching, durability, and biofluid tolerance, emphasizing failure mode-informed evaluation and standardized reporting criteria. Integrating hydration thermodynamics, binding kinetics, mechanical dissipation, and stimulus-gated interfacial transitions, this Review develops design and evaluation principles for reversible wet adhesive systems in complex aqueous and biointerfacial environments.

The crosslinking mechanism, intelligent characteristics, and biomedical applications in human activity sensing and wound management of dynamically crosslinked hydrogels.

Chronic diabetic wounds remain a major clinical challenge due to persistent inflammation, impaired neuro‐immune crosstalk, and dysregulated macrophage polarization. Here, we report an injectable, ultrasound (US)‐activated piezoelectric hydrogel that programmably couples neurogenesis and macrophage reprogramming to accelerate diabetic wound repair. The hydrogel is constructed from dynamic covalent networks among acyl hydrazide hyaluronic acid, benzene boronic acid modified oxidized sodium alginate, and epigallocatechin 3‐gallate, and integrates a neuroactive self‐assembling peptide and piezoelectric PLLA nanofibers. This design confers the hydrogel with injectability, self‐healing, tissue adhesion, and US‐triggered electrical signaling. In vitro, the hydrogel under US promotes M2 macrophage polarization and enhances axonal outgrowth of dorsal root ganglion neurons, establishing bidirectional neurogenesis‐macrophage crosstalk. In a type II diabetic mouse model, the hydrogel markedly accelerates wound closure, elevates the M2/M1 ratio, enhances reinnervation and angiogenesis, and improves collagen remodeling. Transcriptomic analysis of cells and wound tissues identifies coordinated regulation of mitochondrial function and oxidative phosphorylation as a central mechanism. In a diabetic rabbit ear model, the hydrogel with US further attenuates hypertrophic scar formation. This programmable piezoelectric hydrogel converts noninvasive US into spatially confined bioelectrical and biochemical cues, offering a promising strategy to overcome multifactorial barriers in diabetic wound healing.

Polymer-based flexible wireless sensors have demonstrated significant potential in health monitoring. However, existing studies have predominantly focused on material design, energy harvesting, and wireless communication, while research addressing signal attenuation, noise accumulation, and data distortion within wireless links remains relatively limited. Physiological signals are highly susceptible to multi-source interference during acquisition and transmission; without effective data processing and intelligent analysis strategies, monitoring outcomes may fail to meet the accuracy and stability requirements of clinical applications. To address this research gap, this review constructs a comprehensive framework encompassing signal sensing, link transmission, and intelligent processing, building on advances in flexible materials and wireless energy supply modes. Special attention is given to the critical roles of channel compensation, noise suppression, feature extraction, lightweight artificial intelligence models, and edge computing in enhancing data quality and reducing energy consumption. Furthermore, the review systematically analyzes the impact of wireless link stability and energy management on monitoring performance. By reinforcing the synergistic mechanisms between data processing and communication, this work aims to provide design principles and development directions for the next generation of high-reliability, low-power, and intelligent wireless flexible health monitoring systems.

Chronic oxidative stress, mitochondrial dysfunction, impaired Nicotinamide adenine dinucleotide (NAD⁺) biosynthesis, and angiogenesis inhibition are

Non-compressible hemorrhage remains the chief cause of battlefield mortality and civilian trauma death. Here, we propose a hemostatic strategy based on ultrafast self-gelling self-expanding powder of polyacrylic acid (PAA), polyethyleneimine (PEI) and foaming agent, which achieves non-compressible hemorrhage hemostasis through the multiple synergistic effects of expansion plugging, self-gelling adhesion and activating the coagulation factors. The hemostatic powder integrates rapid physical crosslinking with spontaneous gas foaming, exhibits a fast gelation rate, high expansion ratio, strong tissue adhesion, and activation of red blood cells, platelets, and fibrin. The optimized formulation (PP/PT5-TXA30) achieves superior hemostatic performance compared to commercial powders in rat liver volumetric defect, femoral artery and vein transection, as well as complete transection of the subclavian artery and vein in rabbits. Notably, in a lethal porcine model of complete subclavian artery and vein transection, PP/PT5-TXA30 achieves superior performance of non-compressible hemorrhage compared to gauze and XStat™. Additionally, PP/PT5-TXA30 accelerates full-thickness skin wound healing. This work demonstrates a strategy based on ultra-fast self-gelling and self-expanding mechanisms for developing hemostatic materials for non-compressible hemorrhage.