An ailing heart is a place of cell death and decay. But injecting the cardiac tissue with a gelatinous mix of proteins and nanofibers creates a healing environment that promotes cell growth and repair. Experiments with pigs show that the gel’s nanofibers provide scaffolding that optimizes heart reconstruction, scientists from Taiwan and the University of California, San Francisco report in the Aug. 8 Science Translational Medicine. The researchers designed the water-swollen scaffold so it would also slowly release the protein VEGF, which kick-starts blood vessel growth. After 28 days, pigs that received treatment had grown more new blood vessels and arteries than untreated animals (green). Treated pigs’ heart tissue was also abuzz with other cell-repair molecules. The approach might not work if a lot of scar tissue has built up, but it looks promising as a future means for fighting heart failure, the leading cause of death in the western world.