The assembly of biopolymers into a hydrated elastic network often goes along with , a spontaneous process during which the hydrogel slowly shrinks and releases solvent. The tendency to syneresis of calcium-alginate hydrogels, widely used biocompatible materials, is a hindrance to applications for which dimensional integrity is crucial. Although calcium-induced aggregation of specific block-sequences has been long known as the microscopic process at work in both primary cross-linking and syneresis, the nature of the coupling between these structural events and the global deswelling flow has remained so far elusive. We have tackled this issue within the regime of entangled pregels that yield highly cross-linked, self-crowded hydrogels with stiff networks. Using an original, stopped-flow extrusion experiment, we have unveiled a robust, stretched-exponential kinetics of shrinking, spanning more than six decades of time and quasi-independent of the alginate concentration. A careful analysis of the puzzling dynamical features of syneresis in these gels has led us to propose that due to the network rigidity, the calcium-fueled, random collapse events that drive solvent locally, are not thermally activated but rather controlled by the average poroelastic flow itself, according to a self-sustained mechanism described here for the first time.
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http://dx.doi.org/10.1039/d2sm01496c | DOI Listing |
Biosens Bioelectron
January 2025
Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, 213164, Changzhou, China. Electronic address:
Wearable sensors can easily enable real-time and noninvasive glucose (Glu) monitoring, providing vital information for effectively preventing various complications caused by high glucose level. Here, a wearable sensor based on nanozyme-catalyzed cascade reactions is designed for Glu monitoring in sweat. Au nanoparticles (AuNPs) are anchored to the carbonated zeolitic imidazolate framework-8 (ZIF-8-C), endowing the sensor with Glu oxidase (GOx)-like and peroxidase (POD)-like activity.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
January 2025
Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China.
Burns are complex traumatic injuries that lead to severe physical and psychological problems due to the prolonged healing period and resulting physical scars. Owing to their versatility, hydrogels can be loaded with various functional factors, making them promising wound dressings. However, many hydrogel dressings cannot support cell survival for a long time, thereby delaying the process of tissue repair.
View Article and Find Full Text PDFFood Res Int
January 2025
Key Laboratory of Product Packaging and Logistics, Packaging Engineering Institute, College of Packaging Engineering, Jinan University, Qianshan Road 206, Zhuhai 519070, Guangdong Province, China. Electronic address:
Hydrogel indicators promise to monitor food spoilage, but their poor mechanics can cause defects in transport. Herein, a novel zwitterionic double network (DN) hydrogel was developed by polymerizing arylamide and sulfobetaine methacrylate in an alginate-Ca system. This hydrogel exhibited enhanced mechanical properties, including a maximum 2087 % breaking elongation and 135 ± 12 kJ/m toughness, significantly outperforming the current zwitterionic DN hydrogels, which typically exhibit less than 1800 % breaking elongation, capable of supporting 150 g-136 times its own weight.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
School of Materials Science and Engineering, Tongji University, Shanghai 201804, PR China. Electronic address:
Skin grafting techniques are widely used for large burns, trauma, and various acute and chronic wounds, contributing greatly to the repair of traumatic tissue. However, donor site repair and regeneration are often neglected, resulting in infection and delayed healing. Therefore, it is crucial to reduce the rate of donor site infection and improve the speed and quality of healing.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
School of Environmental and Architecture, University of Shanghai for Science and Technology, Shanghai 200093, China. Electronic address:
Carbon dots (CDs) mediated g-CN (CN) is a promising visible-light-driven semiconductor in catalyzing peroxymonosulfate (PMS) for aqueous contaminants remediation. However, the poor dispersibility of powered catalyst and its challenging recyclability impede their broader application. Herein, we embedded FeN bridge within the g-CN framework and immobilized g-CN gel beads (CA/FNCCN) through a 3D cross-linking process with sodium alginate.
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