Supercharged Silk Could Help Regenerate Heart Tissue

Following a heart attack, part of the heart muscle dies, and the heart is unable to fully repair itself. This leads to weakened heart muscle and increased workload, which may result in heart failure over time. To address this, researchers have developed a new microgel from moth silk that can aid tissue regeneration and recovery post-heart attack.

Developed by engineers at the University of New South Wales (UNSW, Sydney, Australia), this innovative material is derived from the silk of a domestic silk moth, transformed into a jelly-like substance called a microgel using light. This microgel is engineered to mimic the mechanical and physical interactions that cells experience within the body, closely resembling human tissue properties. Published in Advanced Functional Materials, the study demonstrated that when the microgel is applied to the skin of mice, it supports cell and blood vessel growth and fosters new tissue generation. The ultimate aim is to further refine this material to improve treatment for cardiovascular diseases and to support heart muscle in post-heart attack patients. The microgel facilitates the appropriate inflammatory responses to encourage cell growth and tissue repair. Additionally, it can be infused with specific proteins or growth factors that are known to promote new blood vessel formation. These factors are already used clinically but degrade quickly when injected directly into the body. Using microgels for delivery could potentially extend their longevity and enhance their effectiveness.

The researchers are planning to develop a cardiac patch that, through the microgel, stimulates heart repair and supports enhanced cardiac function. A significant advancement in this research is the development of a porous microgel, which proves more effective than traditional hydrogels, which are less porous and restrict cell movement and growth within them. This new microgel retains the beneficial properties of hydrogels but with increased porosity, enhancing cellular interaction and integration. This microgel also mirrors the body’s complex, heterogeneous nature, unlike the homogeneity of standard hydrogels. Each microgel particle maintains unique properties, allowing the creation of a complex structure that better replicates the body’s own. Researchers at UNSW are moving forward with experiments injecting their microgel into the hearts of mice to examine its specific repair capabilities in myocardial tissue. Success in these trials could lead to further studies in larger animals such as pigs and eventually to clinical trials in humans, which are expected to begin in about five years.

“Our microgels are made up of entirely of silk, but we can also load them with other molecules such as drugs and proteins that help control inflammation or promote tissue growth, so they work both to support damaged tissue and as a delivery vehicle to promote tissue regeneration,” said A/Prof. Rnjak-Kovacina from the UNSW Graduate School of Biomedical Engineering. “The ultimate goal is to be able inject these microgels into the heart muscle after a heart attack in order to support the heart muscle and help it regenerate.”

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