Hydrogel dressing

Hydrogel dressings are a hydrogel pad in contact with the wound. The hydrogel is a hydrated three-dimensional (3D) network consisting of physically or chemically cross-linked bonds of hydrophilic polymers. They are designed to keep the wound moist and absorbing wound exudate.[1] Hydrogel dressing possesses a highly hydrated 3D polymeric network and can bind several-fold more water as compared to their dry weight and can thereby maintain a high level of moisture at the wound bed.[2] Furthermore, hydrogels offer a platform to load cells, antibacterial agents, growth factors, as well as distinct supplementary and biomacromolecules to accelerate the wound contraction and wound healing process.[3]

An entirely transparent adhesive bandage, with a transparent hydrogel pad and adhesive waterproof plastic film (removable backing is blue and white).

Concerning extracellular matrix similarity, hydrogels used for wound healing applications can provide a cell-friendly 3D environment to promote tissue regeneration, with or without the presence of cells embedded in the scaffold.[4][5] Importantly, all hydrogels need to satisfy the basic requirements of biocompatibility in clinical use as well as possess unique physical and mechanical properties suited for skin wound applications. Moreover, they also need to provide the appropriate microenvironment for vessel ingrowth and cellular proliferation.[6]

Polymers used in hydrogels include chitosan, dextran, kappa-carrageenan, alginate/gelatin and collagen/glycosaminoglycan. Other materials include custom polypeptides, and blends such as chitosan/sodium alginate/poly(vinyl acetate).[6][7] The physical, mechanical, and biological properties of hydrogels used as dressings can modulate by some modifications including chemical modification of polymer, crosslinking strategies, copolymerization, and nanoparticle incorporation.[6][8][9]

A short-peptide-based hydrogel matrix, capable of holding about one hundred times its own weight in water. The thickness of the fibers is on the order of tens of nm, mimicking the fibrous microenvironment found in the extracellular matrix. FESEM image.

The hydrogel dressings can be prepared in the shape of the film which can directly place at the wound site. Besides, there is a new generation of hydrogel dressings that can be sprayed or injected in situ. The prepolymer solution should have shear-thinning behavior to allow spraying/injecting gel on the wound site.[6][9]