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The development of mechanically robust super-lubrication hydrogel materials with sustained lubricity at high contact pressures is challenging. In this work, inspired by the durable lubricity feature of the earthworm epidermis, a multilevel structural super-lubrication hydrogel (MS-SLH) system, the so-called lubricant self-pumping hydrogel, is developed. The MS-SLH system is manufactured by chemically dissociating a double network hydrogel to generate robust and wrinkled lubrication layer, and then laser etching was used to generate cylindrical texture pores as gland-like pockets for storing lubricants. The surface of MS-SLH system shows ultrafast hydration characteristics and reversible pore-closing and pore-opening behavior. The current MS-SLH system shows excellent SL features, as follows: a very low COF (~0.0079) at high contact pressure condition (P: 11.32 MPa); a stable and robust SL lifespan (COF: ~0.0028, P: 8.48 MPa, 100k cylces) without surface wear; and a sustained lubricity period (3700 cycles) with limited lubricant volume (5 μL) in air. The robust and sustained lubricity of the MS-SLH system is likely attributed to the synergy from the strong electrostatic repulsion effect at the sliding interface, the robust but compliant modulus of the dissociation lubrication layer, and the self-pumping lubricant release from the gland-like pocket of the texture pores during the dynamic shearing process. The demonstration experiments based on self-built equipments intuitively exhibit durable SL behavior of MS-SLH system. This work provides an easy strategy for the large-scale manufacture of high-performance water-lubrication coatings suitable for high-end medical devices or moving parts. Developing mechanically robust hydrogels with high lubricity is challenging but desirable. Here, the authors report the development of a layered hydrogel with a robust and wrinkled lubrication layer, and pores for storing lubricants, for sustained lubricity. [ABSTRACT FROM AUTHOR]

Porous hydrogels with high porosity can achieve high matter diffusion and transport efficiency. Achieving both ultrahigh porosity and excellent mechanical properties in porous hydrogels remains a long‐standing challenge, considerably hindering their use in high load‐bearing elastic scaffolds such as artificial articular cartilages and meniscus replacements. Herein, a novel crystalline‐constrained multi‐solvents template preparation method is proposed for synthesizing highly porous hierarchical polyvinyl alcohol hydrogels (P‐exogel) with excellent mechanical properties. The enhanced mechanical characteristics of the P‐exogel are attributed to the crystallinity‐induced network anti‐swelling effect of the pore walls during dynamic template removal. The P‐exogel exhibits a hierarchical and interconnected pore structure with high porosity (81.69%), resulting in ultrafast surface wetting with water (in less than 10 ms). Moreover, the P‐exogel exhibits good tensile breaking strength (2.47 ± 0.53 MPa) with elongation of more than 400%, high toughness (5.61 ± 1.65 MJ m−3), and excellent elastic recovery performance. The pre‐crack testing results further confirm the ultrahigh fracture resistance (18.73 ± 2.52 KJ m−2) of the P‐exogel, which almost surpasses those of all reported and commercial porous hydrogels. The unique network microstructure of the P‐exogel ensures its highly efficient and reversible liquid absorption and release ability during dynamic loading–unloading processes, confirming its great application potential in high load‐bearing elastic scaffolds. [ABSTRACT FROM AUTHOR]

Natural cartilage exhibits superior lubricity as well as an ultra‐long service lifetime, which is related to its surface hydration, load‐bearing, and deformation recovery feature. Until now, it is of great challenge to develop reliable cartilage lubricating materials or coatings with persistent robustness. Inspired by the unique biochemical structure and mechanics of natural cartilage, the study reports a novel cartilage‐hydrogel composed of top composite lubrication layer and bottom mechanical load‐bearing layer, by covalently manufacturing thick polyelectrolyte brush phase through sub‐surface of tough hydrogel matrix with multi‐level crystallization phase. Due to multiple network dissipation mechanisms of matrix, this hydrogel can achieve a high compression modulus of 11.8 MPa, a reversible creep recovery (creep strain: ≈2%), along with excellent anti‐swelling feature in physiological medium (v/v0 < 5%). Using low‐viscosity PBS as lubricant, this hydrogel demonstrates persistent lubricity (average COF: ≈0.027) under a high contact pressure of 2.06 MPa with encountering 100k reciprocating sliding cycles, negligible wear and a deformation recovery of collapse pit in testing area. The extraordinary lubrication performance of this hydrogel is comparable to but beyond the natural animal cartilage, and can be used as compliant coating for implantable articular material of UHMWPE to present, offering more robust lubricity than current commercial system. [ABSTRACT FROM AUTHOR]

Piezo1 is an essential mechanosensitive transduction ion channel in mammals. Its unique structure makes it capable of converting mechanical cues into electrical and biological signals, modulating biological and (patho)physiological processes in a wide variety of cells. There is increasing evidence demonstrating that the piezo1 channel plays a vital role in renal physiology and disease conditions. This review summarizes the current evidence on the structure and properties of Piezo1, gating modulation, and pharmacological characteristics, with special focus on the distribution and (patho)physiological significance of Piezo1 in the kidney, which may provide insights into potential treatment targets for renal diseases involving this ion channel. [ABSTRACT FROM AUTHOR]

Recent advancements in bioengineering and medical devices have been greatly influenced and dominated by synthetic polymers, particularly polyurethanes (PUs). PUs offer customizable mechanical properties and long‐term stability, but their inherent hydrophobic nature poses challenges in practically biological application processes, such as interface high friction, strong protein adsorption, and thrombosis. To address these issues, surface modifications of PUs for generating functionally hydrophilic layers have received widespread attention, but the durability of generated surface functionality is poor due to irreversible mechanical wear or biodegradation. As a result, numerous researchers have investigated bulk modification techniques to incorporate zwitterionic polymers or groups onto the main or side chains of PUs, thereby improving their hydrophilicity and biocompatibility. This comprehensive review presents an extensive overview of notable zwitterionic PUs (ZPUs), including those based on phosphorylcholine, sulfobetaine, and carboxybetaine. The review explores their wide range of biomedical applications, from blood‐contacting devices to antibacterial coatings, fouling‐resistant marine coatings, separation membranes, lubricated surfaces, and shape memory and self‐healing materials. Lastly, the review summarizes the challenges and future prospects of ZPUs in biological applications. [ABSTRACT FROM AUTHOR]