Open Access

Hydrogels

A hydrogel is a network of polymer chains that are hydrophilic, sometimes found as a colloidal gel in which water is the dispersion medium. A three-dimensional solid results from the hydrophilic polymer chains being held together by cross-links.[clarification needed] Because of the inherent cross-links, the structural integrity of the hydrogel network does not dissolve from the high concentration of water. Hydrogels are highly absorbent (they can contain over 90% water) natural or synthetic polymeric networks

Scaffolds in tissue engineering. When used as scaffolds, hydrogels may contain human cells to repair tissue. They mimic 3D microenvironment of cells.

Hydrogel-coated wells have been used for cell cultur

Environmentally sensitive hydrogels (also known as 'Smart Gels' or 'Intelligent Gels'). These hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change.

Injectable hydrogels which can be used as drug carriers for treatment of diseases or as cell carriers for regenerative purposes or tissue engineering.

Sustained-release drug delivery systems. Ionic strength, pH and temperature can be used as a triggering factor to control the release of the drug.

Providing absorption, desloughing and debriding of necrotic and fibrotic tissue

Hydrogels that are responsiv to specific molecules, such as glucose or antigens, can be used as biosensors, as well as in DDS.

Disposable diapers where they absorb urine, or in sanitary napkins

Contact lenses (silicone hydrogels, polyacrylamides, polymacon)

EEG and ECG medical electrodes using hydrogels composed of cross-linked polymers (polyethylene oxide, polyAMPS and polyvinylpyrrolidone)

Water gel explosives

Rectal drug delivery and diagnosis

Encapsulation of quantum dots

Breast implants

Glue

Granules for holding soil moisture in arid areas

Dressings for healing of burn or other hard-to-heal wounds. Wound gels are excellent for helping to create or maintain a moist environment.

Reservoirs in topical drug delivery; particularly ionic drugs, delivered by iontophoresis (see ion exchange resin).

Materials mimicking animal mucosal tissues to be used for testing mucoadhesive properties of drug delivery systems

Thermodynamic electricity generation. When combined with ions allows for heat dissipation for electronic devices and batteries and converting the heat exchange to an electrical charge.