Jing Xie

A bioinspired mechano-catalytic hydrogel leaf that harnesses light-driven nastic motion to actively regulate photocatalytic water purification.

Elevated interfacial friction and acidified microenvironments in osteoarthritis (OA) drive coupled mechanical–biological failure, destabilizing lubrication and amplifying cellular stress, thereby accelerating cartilage degeneration and limiting therapeutic efficacy. Here, we report pH‐responsive supramolecular nanogels (NGs) composed of benzimidazole‐modified polyethylene glycol (PEG‐BM) and β‐cyclodextrin‐modified hyaluronic acid (HA‐CD) that undergo a microenvironment‐triggered lubrication‐regime transition. Surface force apparatus measurements directly revealed a transition from interfacial sliding under physiological conditions to rolling‐assisted lubrication under acidic conditions, accompanied by nanoscale interfacial structures consistent with a rolling‐bearing‐like mechanism. All‐atom molecular dynamics simulations identified protonation‐induced weakening of the β‐CD/BM host–guest motif and enhanced guest hydration as molecular drivers of pH‐triggered supramolecular reconstruction, providing a molecular basis for the adaptive interfacial transition. Comparative transcriptomic analysis showed that dexamethasone‐loaded NGs (NGD) were associated with ECM–receptor interaction, focal adhesion, integrin‐mediated adhesion, actin‐cytoskeletal organization and mechanosensitive cellular responses. In vivo, drug‐free NGs achieved therapeutic outcomes comparable to NGD. Mechanistically, protonation‐driven host–guest reconstruction enables pH‐adaptive lubrication, which is associated with matrix‐interactive and mechanosensitive cellular programs favorable for matrix homeostasis and tissue preservation. These findings establish a multiscale mechanobiological framework linking molecular reconstruction, adaptive interfacial lubrication and matrix‐preserving biological remodeling, providing a strategy for microenvironment‐responsive mechanical regulation in OA therapy.

We design a drug-free, asymmetric patch with ROS-scavenging ability for oral ulcer (OU) treatment. The asymmetric patch exhibited instant wet adhesion and effective anti-inflammation, regulated cellular redox status and accelerated OU healing.

Repairing large bone defects remains a significant clinical challenge, as they exceed the bone's innate regenerative capacity. The current gold standard, autologous bone grafting, is constrained by donor site morbidity, limited tissue availability, and additional surgical risks. Bone tissue engineering offers a compelling alternative; yet achieving fully functional, vascularized bone regeneration remains challenging. Inspired by the hierarchical architecture of native osteons, a dual-ring hydrogel scaffold was developed by incorporating the zwitterionic monomer 2-(methacryloyloxy)ethyl choline phosphate (MCP) into a gelatin methacryloyl (GelMA) matrix. This design facilitated spatially programmed encapsulation of human umbilical vein endothelial cells (HUVECs) and bone marrow-derived mesenchymal stem cells (BMSCs), replicating the cellular spatial organization of native osteons. MCP integration imparted the GelMA hydrogel with enhanced hydrophilicity, tunable porosity, and optimized mechanical and degradable properties. Optimized GelMA-MCP formulations supported the cell-specific viability and functional activity of HUEVCs and BMSCs, while the spatial configuration promoted synergistic angiogenesis and osteogenesis. Both in vitro and in vivo evaluations demonstrated that the osteon-like scaffold significantly enhanced angiogenesis and bone regeneration compared to mixed or single-cell controls. This study describes a modular and biomimetic strategy for engineering vascularized bone tissue through the integration of functional monomers and spatially guided cell patterning.

Osteoarthritis (OA) is a degenerative bone and joint disease characterized by cartilage degradation and an inflammatory environment. Consequently, strategies aimed at remodeling the damaged joint microenvironment by concurrently enhancing lubrication and alleviating inflammation are essential for improving therapeutic efficacy. Herein, we designed multifunctional cyclic brush polymer (CP) nanomicelles composed of surface-grafted zwitterionic poly(sulfobetaine methacrylate) (PSBMA) brushes and a hydrophobic core of PHEMA. Benefiting from the unique cyclic brush topology and hydrated lubrication properties of PSBMA, the CPs exhibited effective lubrication. Tribological and wear tests showcased the CPs significantly reduced the coefficient of friction and surface wear under shear forces. Furthermore, the CPs served as nanocarriers for encapsulating the anti-inflammatory drug resveratrol (RSV) through hydrophobic interactions, serving as drug-loaded nanomicelles CP@RSV. In vitro studies indicated that CP@RSV exhibited excellent cytocompatibility, effectively eliminated reactive oxygen species (ROS) in cells and reversed mitochondrial dysfunction, thereby modulating the oxidative stress microenvironment. In conclusion, CP@RSV integrates enhanced lubrication with antioxidation properties, representing a promising strategy for the treatment of OA.

A fluid-variable STU hydrogel made from silk fibroin, tannic acid, and urea rapidly seals dentinal tubules over 660 μm deep in 3 min, with excellent biocompatibility, stability, and clinical potential for dentin hypersensitivity treatment.

Osteoarthritis (OA), which disables articular cartilage, affects millions of people. The self-healing capacity is inhibited by internal oxidative stress and external lubrication deficiency and enzymatic degradation. To overcome these challenges, a tailored cartilage-armor is designed to ameliorate the inflamed cartilage, which is implemented by a novel collagen type II (Col II)-binding peptide conjugated zwitterionic polymer (PSB-b-PColBP, PSP). By mimicking natural lubricin, PSP specifically targets the cartilage surface and forms an in situ hydration armor. This engineered cartilage-armor can prevent enzymatic cartilage degradation (nearly 100% resistance to catabolic enzymes) and provide durable lubrication properties (COF < 0.013 for 500 cycles). An autophagy-activation process, absent in previous biomimetic lubricants, enhances the enzymatic activity of the tailored cartilage-armor, offering effective anti-oxidant properties to suppress oxidative stress. By inhibiting the PI3K-Akt/NF-κB signaling pathway, chondrocytes protected by the tailored armor can secrete a cartilage matrix even in inflammatory microenvironments. In OA rat models, osteophyte formation and the inflammatory response have been inhibited by the cartilage-armor, demonstrating a therapeutic effect comparable to most drug-loaded systems. This study underscores the potential of tailoring cartilage-armor with the cartilage targeting and autophagy-activating properties in integrating offensive–defensive mechanisms for cartilage remodeling. This represents an alternative strategy for clinical OA therapy.

Commencing with the breakdown of the diabetic osteoimmune microenvironment, multiple pathogenic factors, including hyperglycemia, inflammation, hypoxia, and deleterious cytokines, are conjointly involved in the progression of diabetic periodontal bone regeneration. Based on the challenge of periodontal bone regeneration treatment and the absence of real‐time feedback of blood oxygen fluctuation in diabetes mellitus, a novel self‐adaptive hyperthermia supramolecular cascade nano‐reactor ACFDG is constructed via one‐step supramolecular self‐assembly strategy to address multiple factors in diabetic periodontal bone regeneration. Hyperthermia supramolecular ACFDG possesses high photothermal conversion efficiency (32.1%), and it can effectively inhibit the vicious cycle of ROS‐inflammatory cascade through catalytic cascade reactions, up‐regulate the expression of heat shock proteins (HSPs) under near‐infrared (NIR) irradiation, which promotes periodontal bone regeneration. Remarkably, ACFDG can provide real‐time non‐invasive diagnosis of blood oxygen changes during periodontal bone regeneration through photoacoustic (PA) imaging, thus can timely monitor periodontal hypoxia status. In conclusion, this multifunctional supramolecular nano‐reactor combined with PA imaging for real‐time efficacy monitoring provides important insights into the biological mechanisms of diabetic periodontal bone regeneration and potential clinical theranostics.