From the Guidelines
Hydrogels are three-dimensional networks of hydrophilic polymers that can absorb and retain large amounts of water or other aqueous solutions, making them highly swollen and flexible 1.
Key Characteristics
- They are commonly used in medical applications, such as wound dressings, contact lenses, and drug delivery systems, due to their biocompatibility, permeability, and ability to mimic the properties of natural tissues 1.
- Hydrogels can be made from a variety of materials, including natural polymers like collagen and hyaluronic acid, and synthetic polymers like polyethylene glycol and polyvinylpyrrolidone 1.
- They can be tailored to have specific properties, such as pH sensitivity, temperature responsiveness, and controlled release of therapeutic agents 1.
Applications
- Hydrogels are used in tissue engineering to create scaffolds for cell growth and differentiation 1.
- They are also used in drug delivery to control the release of therapeutic agents 1.
- Additionally, hydrogels are used in wound healing to promote tissue repair and regeneration 1.
Types of Hydrogels
- Natural hydrogels are made from natural polymers like collagen and hyaluronic acid 1.
- Synthetic hydrogels are made from synthetic polymers like polyethylene glycol and polyvinylpyrrolidone 1.
- Hybrid hydrogels are made from a combination of natural and synthetic polymers 1.
- Supramolecular hydrogels are made from self-assembling monomers that form a network of hydrogen bonds or other non-covalent interactions 1.
From the Research
Definition of Hydrogels
- Hydrogels are crosslinked polymer chains with three-dimensional (3D) network structures, which can absorb relatively large amounts of fluid 2.
- They are three-dimensional networks of polymer chains containing large amounts of water in their structure 3.
- Hydrogels are hydrophilic 3D networks that are able to ingest large amounts of water or biological fluids 4.
- They are three-dimensional hydrophilic polymeric networks that can be made from a wide range of natural and synthetic polymers 5.
- Hydrogels are three-dimensional networks of hydrophilic polymers able to absorb and retain a considerable amount of water or biological fluid while maintaining their structure 6.
Properties of Hydrogels
- Hydrogels have high water content, soft structure, and porosity, which closely resemble living tissues 2.
- They have attractive physicochemical properties, including flexibility, softness, biodegradability, and biocompatibility 3.
- Hydrogels can be physically or chemically cross-linked depending on the structure 3.
- They require variable time to reach an equilibrium swelling due to the variable diffusion rates of water sorption, capillary action, and other modalities 4.
Applications of Hydrogels
- Hydrogels have been applied in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine 2.
- They have potential biomedical applications, including 3D cell cultures, drug delivery, wound dressing, and tissue engineering 2.
- Hydrogels can be used for bone regeneration, wound healing, drug delivery, bioimaging, and therapy 3.
- They can be used as drug delivery systems for the controlled release of various bioactives 6.