Next time you're clearing your ceiling corners of spider webs, just think "wow, they're trying to grow an organ on that." Well, not actual spider webs, but synthetic versions of them.

Researchers are genetically engineering fibers of spidroin, a protein that makes up the bulk of spider silk. Spidroin may be the answer to the challenge of finding a compatible scaffold to grow a human heart. Finding a viable scaffold is among the greatest challenges in the cutting edge field of organ growing.

A matrix for the human heart must have mechanical and elastic properties similar to the heart, be biocompatible, and allow electrical properties essential to the proper functioning of the heart. Scientists created two forms of synthetic spidroin and found the silk from these two proteins have high biocompatibility. The next step was to show that cardiac cells grown on a spider silk matrix achieve coordinated electrical activity that orchestrates the pumping actions of the heart.

They spun blends of spidroin to form matrices on glass disks. They then applied mouse cardiac cells to the scaffolds sitting in a growth medium and compared how well the cells adhered to the silk against other natural protein matrices. This is crucial because cells that don't attach die.

One formulation of the spider silk bound 90% as many cells as the control matrix. Left to grow for three days, the cells formed a uniform layer across the matrix and began to show electrical activity and coordinated movements of contraction.

A lot more testing is ahead but so far it's encouraging. Spider silk could be the next wonder material whether it's body armor, better bandages, or in this case' a working heart.