Provided are superabsorbent materials composed of agar, and one or more water-soluble natural polysaccharides, and dietary compositions containing such superabsorbent materials. The disclosed superabsorbent materials have various food and therapeutic applications and can be used as loading vehicles for nutrients and therapeutic agents. Also provided are methods for preparing such superabsorbent materials.

Disclosed are an electrically conductive hydrogel having a graphene network and a method for fabricating the same. The electrically conductive hydrogel is fabricated by thermal annealing of granular hydrogel, and thus it has a porous structure, excellent electrical conductivity, and improved compressive modulus and yield stress. Accordingly, the electrically conductive hydrogel may be advantageously used in biomedical applications, such as scaffolds for tissue engineering, bioelectrodes, and biosensors.

A heparinized microsphere is provided, including a polymer, heparin and a cross-linking agent. The polymer has at least one functional group includes a hydroxyl group, a carboxyl group, an amine group, or a combination thereof. The polymer and the heparin are cross-linked by a cross-linking agent. A method of preparing heparinized microsphere and a method of isolating exosomes are also provided to achieve purification of exosomes with high purity.

A hydrogel structure (10) includes: a continuous phase (11) of a first hydrogel; and a dispersion phase (12) of a second hydrogel, the dispersion phase being dispersed in the continuous phase (11). A ratio of a local minimum value of a load after break to a breaking load (a local minimum value of a load after break/a breaking load) of the hydrogel structure (10) is 0.1 or more.