Multifunctional, high-performance wearable heaters are highly desired for future human health-related applications but are generally hindered by the absence of flexibility, air-permeability, and clothes-knittability. Here, polymeric textile-based wearable heaters are constructed by decorating an MXene on the fiber surface via a simple solution dip coating technique. Alkali pretreatment of textiles enables strong interaction between the MXene and textiles through the synergistic effect of hydrogen bonds and physical rivet action. These MXene-decorated textiles (M-textiles) not only maintain the innate flexibility, comfort, light-weight and permeability characteristics of the textile substrates, but also exhibit exceptional heating performance including dual-driven energy conversion (electrothermal and photothermal), wide temperature range (40–174 °C in electrothermal and 40–204 °C in photothermal conversion), safe operating conditions (1–3.5 V for electrothermal, and NIR/FIR or abundant sunlight for photothermal conversion), and fast thermal response (reaching over 100 °C within 25 s at 2.5 V or within seconds in photothermal conversion). Impressively, the M-textiles integrate superb resistance to fire and bacteria, and a high electromagnetic interference (EMI) shielding efficiency of 42.1 dB in the X-band. These multifunctional M-textile wearable heaters are highly promising for applications in warmth-keeping, thermotherapy, deicing, heating water, EMI shielding, and antibacterial and fire protection, and are ideal candidates for future health management and protection.

Due to their mechanical flexibility, conductive hydrogels have been widely investigated in the fields of flexible electronics and soft robots, but their non-negligible disadvantages, such as poor toughness and limited self-healing, severally restrict their practical application. Herein, gallium indium alloy (EGaIn) is utilized to initiate the polymerization and simultaneously serve as flexible fillers to construct a super-stretchable and self-healing liquid metal/polyvinyl alcohol/p(acrylamide-co-octadecyl methacrylate) (liquid metal/PVA/P(AAm-co-SMA)) double network hydrogel (LM hydrogel). The synergistic effect of the rigid PVA microcrystal network and the ductile P(AAm-co-SMA) hydrophobic network, together with the ionic coordination and hydrogen bonds between polymer networks (multiple physical cross-links), endow the LM hydrogel with excellent super-stretchability (2000%), toughness (3.00 MJ m⁻³), notch resistance, and self-healing property (healing efficiency > 99% at 25 °C after 24 h). The LM hydrogel exhibits sensitive strain sensing behavior, allowing human–computer interaction to achieve motion recognition and health monitoring. Significantly, owing to the excellent photothermal effect and low infrared emissivity of EGaIn, the LM hydrogel reveals great potential in infrared camouflage. The work of self-healing conductive liquid metal hydrogels will promote the research and practical application of hydrogels and liquid metal in intelligent devices and military fields.

Cartilage injury originating from trauma or osteoarthritis is a common joint disease that can bring about an increasing social and economic burden in modern society. On account of its avascular, neural, and lymphatic characteristics, the poor migration ability of chondrocytes, and a low number of progenitor cells, the self-healing ability of cartilage defects has been significantly limited. Natural hydrogels, occurring abundantly with characteristics such as high water absorption, biodegradation, adjustable porosity, and biocompatibility like that of the natural extracellular matrix (ECM), have been developed into one of the most suitable scaffold biomaterials for the regeneration of cartilage in material science and tissue engineering. Notably, natural hydrogels derived from sources such as animal or human cadaver tissues possess the bionic mechanical behaviors of physiological cartilage that are required for usage as articular cartilage substitutes, by which the enhanced chondrogenic phenotype ability may be achieved by facilely embedding living cells, controlling degradation profiles, and releasing stimulatory growth factors. Hence, we summarize an overview of strategies and developments of the various kinds and functions of natural hydrogels for cartilage tissue engineering in this review. The main concepts and recent essential research found that great challenges like vascularity, clinically relevant size, and mechanical performances were still difficult to overcome because the current limitations of technologies need to be severely addressed in practical settings, particularly in unpredictable preclinical trials and during future forays into cartilage regeneration using natural hydrogel scaffolds with high mechanical properties. Therefore, the grand aim of this current review is to underpin the importance of preparation, modification, and application for the high performance of natural hydrogels for cartilage tissue engineering, which has been achieved by presenting a promising avenue in various fields and postulating real-world respective potentials.