From the lectures on tissue engineering, I found the idea of fixing the body with the same materials that make up the body really interesting, and how this can help with rejection which is faced by foreign materials in the body. This led me to look more into recent advances in tissue engineering, where I came across this news article about a new biomaterial with the potential for healing damaged heart tissue after a heart attack.

What is it?

A team at the University of California San Diego has developed a new hydrogel, which is a polymer chain complex that can hold a lot of water. The hydrogel contains extracellular matrix (ECM), from the myocardium, or heart muscles. The ECM has been decellularized to isolate the matrix, enzymatically digested, and fractionated. In the body, cells exist inside a matrix, which contains proteins and other molecules to give structure to tissues and aid in cell communication. The original hydrogel that was developed was too large to target leaky blood vessels. This issue was solved by centrifuging the gel in its liquid stage to remove larger particles.

How does it work?

The hydrogel is injected intravenously, taking advantage of the bloodstream to access hard to reach organs. After a heart attack, gaps form between the endothelial cells which line blood vessels. When the hydrogel reaches the damaged tissue, it binds to these cells, bridging these gaps and promoting new cell growth and repair, and also reducing inflammation. The gel takes roughly 3 days to degrade after administration.

In their initial clinical trial, the gel was directly injected into the heart muscle. This came with the disadvantage of having to wait at least a week after the heart attack, as injecting the damaged tissue by needle directly after is likely to do more harm than good. Intravenous injection can be done immediately. The hydrogel can then work together with other treatments such as angioplasty or a stent. In addition, the gel is more evenly distributed around the tissue rather than being concentrated around the site of injection.

The Next Steps

This new way of administering the gel has been successfully tested on rodents and pigs to treat damaged heart tissue. The research group are looking to get authorisation from the FDA to perform human trials, with plans to start in the next couple of years. They are also exploring the potential of the hydrogel to treat other inflammatory diseases such as traumatic brain injury and pulmonary arterial hypertension with preclinical trials on rodents.

In the UK there are around 100,000 hospital admissions every year for heart attacks- or one every five minutes. Over the past 50 years, there has been major advances in treatment and survival. In the 19080s roughly 25% of people having a heart attack would die, nowadays, if treated quickly, the chance of dying during a heart attack is 2-4%. In the future this number will hopefully reduce even more with advances in bioengineering.

References

British Heart Foundation, 2023. UK Factsheet. [Online]
[Accessed 9 March 2023].

Spang, M. T. et al., 2022. Intravascularly infused extracellular matrix as a biomaterial for targeting and treating inflamed tissues. Nature Biomedical Engineering, 29 December, Volume 7, pp. 94-109.

Thomas, M., n.d. Focus on: Heart Attacks [Interview] n.d.

University of California – San Diego, 2023. Groundbreaking Biomaterial Heals Tissues From the Inside Out. [Online]
Available at: https://scitechdaily.com/groundbreaking-biomaterial-heals-tissues-from-the-inside-out/ [Accessed 8 March 2023].