Hydrogel for the heart may prevent a common post-surgical complication
After open-heart surgery has been performed, the scar tissue that forms on the heart will sometimes stick to the tissue surrounding it. Such complications are known as adhesions, and a new hydrogel may help keep them from occurring.
Although not always a serious problem, cardiac adhesions can prevent the heart from functioning normally, plus they may make it impossible to safely perform subsequent heart surgeries. The latter problem particularly applies to children, since they may require multiple procedures as their heart grows.
That's where the hydrogel is designed to come in. It's being developed by a team at the University of California San Diego, and consists of two parts: a water-soluble polymer base material known as polyethylene glycol (PEG), and an organic compound called catechol that contains a muscle-binding amino acid by the name of L-dopa.
Two different formulations of the PEG – one of which is combined with the catechol – are contained in separate chambers of an applicator device. After the heart surgery has been completed, that device is used to simultaneously spray the two types of PEG onto the surface of the muscle. As they mix, their molecules crosslink with one another, forming an elastic hydrogel that binds to the cardiac tissue.
That gel serves as a barrier which keeps adhesions from occurring, while still allowing the heart to expand and contract normally. It harmlessly dissolves within six to eight weeks – which is far longer than the 30-day post-surgical period in which adhesions typically form – and it doesn't produce an inflammatory response in the heart.
In tests conducted so far, the hydrogel completely prevented cardiac adhesions in rats, and made them much less severe in pigs. The hydrogel is now being commercialized by spinoff company Karios Technologies, with hopes of it being cleared for use on human patients within five years.
"Our work is an engineering solution driven by a medical problem," says the lead scientist, Prof. Karen Christman. "And now it's poised to significantly improve cardiac surgery, both for adults and children."
A paper on the research was recently published in the journal Nature Communications.