Injectable hydrogel shows promise in boosting survival rates for patients with congenital heart defects

By Stephanie Srakocic | Fact-checked by Davi Sherman
Published March 6, 2024

Key Takeaways

  • A new study shows promising results of injectable hydrogel as a treatment for hypoplastic left heart syndrome.

  • In mice, injectable hydrogel was able to improve heart function, slow down scarring, and increase the amount of pressure and volume the right ventricle could handle.

A study published March 6 in the Journals of the American College of Cardiology by a research team from the University of California San Diego, Georgia Institute of Technology, and Emory University shows promising results from trials testing a potential new use of injectable hydrogel. In recent years, injectable hydrogel has been tested for use in treating multiple heart conditions. In 2019, the Food and Drug Administration (FDA) approved a Phase 1 trial of its use in people who suffered a heart attack.[]

 The new study focused on pediatric patients with congenital heart conditions. Specifically, researchers looked at the possibility that injectable hydrogel could help patients with hypoplastic left heart syndrome, a condition responsible for 40% of deaths associated with heart defects in newborns.[] 

Currently, all patients with hypoplastic left heart syndrome require three open heart surgeries before their fifth birthday. Surgeries reroute oxygenated blood supply to the right ventricle. Even after surgeries, however, children with this condition require medication, a special diet, and physical therapy. Typically, after several years of pumping blood for the entire body, the right heart ventricle begins to fail, and patients will require a heart transplant. Patients with hypoplastic have a 35% survival rate.[] 

In testing, researchers injected hydrogen into the right ventricle of rats. The hydrogel improved heart function, allowing the heart to tolerate increased blood pressure and volume. The treatment also slowed down the rate of scarring and abnormal right ventricle muscle growth and affected gene expression related to cardiac repair.[] 

If hydrogel injections produce the same results in humans, they could increase the amount of time that a patient’s heart functions. It could give children with hypoplastic left heart syndrome longer before they need a transplant. Potentially, the treatment could allow children to wait until they can get on an adult heart transplant list, thereby increasing the chances of finding a donor organ.[] 

Researchers hope this could improve patients’ quality of life, enabling physical growth and better cognitive development.[]

The FDA has approved further testing of this potential treatment. Emory University and the Georgia Institute of Technology will join Children’s Healthcare of Atlanta to begin recruiting volunteers for a clinical trial that will test the treatment's efficacy in newborns with hypoplastic left heart syndrome.[]

Hydrogel and the heart

Hydrogel is made from cardiac extracellular matrix. When injected, it can cause a patient’s cells to repopulate areas of damaged cardiac tissue and improve cardiac function. Researchers prepared the hydrogel with tissue from the right and left ventricles of pig hearts.[] 

In the hypoplastic left heart syndrome treatment study, results from the hydrogel created by the left and right ventricles differed. While hydrogel from the left ventricle and right ventricle tissue were both able to improve the heart’s ability to pump blood and reduce scarring and abnormal growth, the latter was more effective overall.  

Hydrogel’s future as a heart health treatment

Multiple studies have examined hydrogel’s use as a heart treatment over the past decade. Injectable hydrogel has a range of advantages that make it especially intriguing. It’s easily injected through minimally invasive IV delivery and is both stable and biocompatible. In testing, hydrogel has been shown to provide benefits as a treatment for heart disease, heart scarring, arrhythmias, damage caused by radiation treatments, and heart failure.[] 

Hydrogel patches have also been tested as a treatment option. The patches, which are sutured or glued directly onto the cardiac wall, have demonstrated the ability to provide support to damaged cardiac tissue. The treatment is also linked to improvements in electric cardiac signal conduction and the reduced chance of an embolism.[]

Hydrogel treatments are still in development. Trials involving larger animals and human subjects, as well as tests that will explore long-term effects, will be vital. However, research has already shown benefits, such as restored heart function, increased tissue repair, and reduced stress on the heart. As additional research is completed and delivery methods, dosages, and formulations are tested, hydrogel has the potential to emerge as a key player in heart disease treatment.[]

In a 2024 comprehensive review of hydrogel treatment currently being tested for myocardial infraction, study author Qiaxin Xu concluded that:

Challenges and opportunities coexist. Although hydrogels for cardiac tissue engineering have made outstanding progress, many challenges still need to be addressed before these methods can be safely used in clinical practice…It is anticipated that, in the near future, injectable hydrogels and heart patches will bring increased hope and confidence to a growing number of myocardial infarction patients, ultimately benefiting their well-being.[]

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