Hydrogels are created from crosslinked polymers that are water-insoluble. Polymer hydrogels absorb significant amounts of aqueous solutions, and therefore have a high water content. This high water content makes hydrogel more similar to living body tissues than any other material for tissue regeneration. Additionally, polymer scaffolds using self-healing hydrogels are structurally similar to the extracellular matrices of many of the tissues. Scaffolds act as three-dimensional artificial templates in which the tissue targeted for reconstruction is cultured to grow onto. The high porosity of hydrogels allows for the diffusion of cells during migration, as well as the transfer of nutrients and waste products away from cellular membranes. Scaffolds are subject to harsh processing conditions during tissue culturing. These include mechanical stimulation to promote cellular growth, a process which places stress on the scaffold structure. This stress may lead to localized rupturing of the scaffold which is detrimental to the reconstruction process. In a self-healing hydrogel scaffold, ruptured scaffolds have the ability for localized self-repair of their damaged three-dimensional structure.
Current research is exploring the effectiveness of using various types of hydrogel scaffolds for tissue engineering and regeneration including synthetic hydrogels, biological hydrogels, and biohybrid hydrogels.
In 2019, researchers Biplab Sarkar and Vivek Kumar of the New Jersey Institute of Technology developed a self-assembling peptide hydrogel that has proven successful in increasing blood vessel regrowth and neuron survival in rats affected by Traumatic Brain Injuries (TBI).  By adapting the hydrogel to closely resemble brain tissue and injecting it into the injured areas of the brain, the researchers’ studies have shown improved mobility and cognition after only a week of treatment. If trials continued to prove successful, this peptide hydrogel may be approved for human trials and eventual widespread use in the medical community as a treatment for TBIs.  This hydrogel also has the potential to be adapted to other forms of tissue in the human body, and promote regeneration and recovery from other injuries.