Interpenetrating polymer network (IPN) hydrogel beads of carrageenan-sodium alginate (Caralgi) were prepared under mild conditions. Betamethasone acetate, as a water-soluble drug model, was simultaneously loaded while the hydrogel network was being formed. The effect of pH and temperature of the preparative media on the drug loading efficiency was investigated. Maximum loading efficiency (71%) was achieved at pH 4.8 and 55°C. The chemical structure and morphology of the Caralgi IPN hydrogels with and without drug were studied using FTIR and SEM analyses. The system exhibited a loading efficiency that depended on the pH and temperature. The in vitro release behavior by Caralgi IPN samples, prepared under various conditions, was evaluated and compared with that of the non-IPN alginate-Ca²⁺ and carrageenan-K ⁺ hydrogels at pH 1.2 and 7.4.

Hydrogel beads based on the carbohydrate biopolymers kappa-carrageenan and sodium alginate were newly prepared. Both classical and experimental design (Taguchi) methods were used to obtain the opti...

Hydrogel-based wearable electrochemical biosensors (HWEBs) are emerging biomedical devices that have recently received immense interest. The exceptional properties of HWEBs include excellent biocompatibility with hydrophilic nature, high porosity, tailorable permeability, the capability of reliable and accurate detection of disease biomarkers, suitable device–human interface, facile adjustability, and stimuli responsive to the nanofiller materials. Although the biomimetic three-dimensional hydrogels can immobilize bioreceptors, such as enzymes and aptamers, without any loss in their activities. However, most HWEBs suffer from low mechanical strength and electrical conductivity. Many studies have been performed on emerging electroactive nanofillers, including biomacromolecules, carbon-based materials, and inorganic and organic nanomaterials, to tackle these issues. Non-conductive hydrogels and even conductive hydrogels may be modified by nanofillers, as well as redox species. All these modifications have led to the design and development of efficient nanocomposites as electrochemical biosensors. In this review, both conductive-based and non-conductive-based hydrogels derived from natural and synthetic polymers are systematically reviewed. The main synthesis methods and characterization techniques are addressed. The mechanical properties and electrochemical behavior of HWEBs are discussed in detail. Finally, the prospects and potential applications of HWEBs in biosensing, healthcare monitoring, and clinical diagnostics are highlighted.