Brittle materials propagate opening cracks under tension. When stress increases beyond a critical magnitude, then quasistatic crack propagation becomes unstable. In the presence of several precracks, a brittle material always propagates only the weakest crack, leading to catastrophic failure. Here, we show that all these features of brittle fracture are fundamentally modified when the material susceptible to cracking is bonded to a hydrogel, a common situation in biological tissues. In the presence of the hydrogel, the brittle material can fracture in compression and can hydraulically resist cracking in tension. Furthermore, the poroelastic coupling regularizes the crack dynamics and enhances material toughness by promoting multiple cracking.
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http://dx.doi.org/10.1103/PhysRevLett.115.188105 | DOI Listing |
J Control Release
January 2025
Guangdong Provincial Engineering Research Center of Molecular Imaging, Guangdong-Hong Kong-Macao University Joint Laboratory of Interventional Medicine, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, Guangdong, China; Zhuhai Hospital of Integrated Traditional Chinese & Western Medicine, Zhuhai, Guangdong, China. Electronic address:
Dry eye disease (DED) is a complex and multifactorial ocular surface disease. Reactive oxygen species (ROS) are of pivotal importance in the inflammatory processes and biological dysfunction associated with DED. In this study, an injectable hydrogel, designated as OHACDgel, was created by combining oxidized HA-containing aldehyde groups (OHA) and gelation (gel) via dynamic covalent linkages of the hydrazine bonds, is employed as the carrier, while polyethylene imine-functionalized carbon dots (PEI-CD) can form dynamic chemical bonds with the hydrogel, thus prolonging the retention time of the ocular.
View Article and Find Full Text PDFFood Chem
January 2025
Department of Food Science and Technology, College of Agriculture, Isfahan University of Technology, Isfahan 84156-83111, Iran. Electronic address:
A colorimetric-fluorescence ripeness indicator, based on copper nanoparticles and carbon quantum dots doped with nitrogen (CuNPs/N@CQD) immobilized in agar hydrogel (AGH-CuNPs/N@CQDs) for ethylene gas detection, was developed for detecting the ripening of bananas. Ethylene could reduce the fluorescence intensity of CuNPs/N@CQDs and cause a red shift of the LSPR peak. The prepared AGH-CuNPs/N@CQDs indicator had an irreversible response to ethylene with LOD and LOQ of 9.
View Article and Find Full Text PDFBiomaterials
January 2025
School of Pharmacy, Nanjing Medical University, Nanjing, 211166, China. Electronic address:
The therapeutic agent-based self-assembled hydrogel is gaining interest for biomedical applications, because it overcomes the poor biodegradability and low therapeutic agent loading of conventional polymer gelator-based hydrogel. Here, we present rhein lysinate (RHL), a therapeutic agent that self-assembles to form a stable hydrogel through the π-π stacking and hydrogen bonding interactions, while also exerting anti-neuroinflammatory effect. As a small molecular hydrogelator, RHL has significantly improved water solubility and enhanced self-assembly and gelation capabilities compared to the natural anthraquinone rhein.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Hydrogel-based sensors typically demonstrate conspicuous swelling behavior in aqueous environments, which can severely compromise the mechanical integrity and distort sensing signals, thereby considerably constraining their widespread applicability. Drawing inspiration from the multilevel heterogeneous structures in biological tissues, an antiswelling hydrogel sensor endowed with high strength, rapid self-recovery, and low swelling ratio was fabricated through a water-induced phase separation and coordination cross-linking strategy. A dense heterogeneous architecture was developed by the integration of "rigid" quadridentate carboxyl-Zr coordination bonds and "soft" hydrophobic unit-rich regions featuring π-π stacking and cation-π interactions into the hydrogels.
View Article and Find Full Text PDFFront Bioeng Biotechnol
January 2025
Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, Research Unit of Oral and Maxillofacial Regenerative Medicine, Chinese Academy of Medical Sciences, Shanghai, China.
A one-step hydrothermal method was applied to prepare carbon dots (CDs) with superior fluorescence properties using chitosan as a carbon source. The as-prepared carbon dots were then grafted onto a sodium alginate-gelatin hydrogel film to form a fluorescent hydrogel film (FHGF), emitting at 450 nm under excitation of 350 nm light. In comparison to the CDs, the fluorescence intensity of this film was maintained over 90.
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