Hydrogels, which are soft materials formed by cross-linking polymers, could have a variety of medical applications. In research published in Advanced Science, investigators developed an injectable hydrogel containing components of fish swim bladders and used it to repair damaged heart tissue.

The fish swim bladder is an organ that aids fish in floating in water and is composed of collagen, glycosaminoglycans, and elastin, closely resembling parts of the human heart.

Experiments revealed that the researchers’ fish swim bladder–based hydrogel enhances cardiac cell adhesion and stretching while promoting new blood vessel formation and causing immune cells to fight inflammation. The hydrogel also provided sustained support for heart contractions. These effects were seen after hydrogel treatment in cultured cells and in a rat model of ischemic heart failure.

“The irreversible loss of cardiomyocytes—or heart muscle cells—following ischemic events underpins the pressing need for novel regenerative strategies in myocardial repair,” said lead corresponding author Zhihong Wang, Ph.D., of Nankai University in China.

“By harnessing the unique bioactivity of fish swim bladder–derived biomaterials to enhance hydrogel performance, this innovative approach promises to significantly advance the restoration of cardiac function and overcome current therapeutic limitations.”