Have you ever wondered if we could heal tissues in the body from damage that can be detrimental? In December 2022, a journal on Nature, brought to light from the University of California San Diego, discovered a new biomaterial that can heal tissues from the inside out 1,3 . Karen Christman, professor of bioengineering at the University of California San Diego and the lead researcher for the team who developed the biomaterial, stated, “It is a new approach to regenerative engineering 1 .”
Christman and colleagues developed a hydrogel produced from the natural scaffolding of cardiac muscle tissue known as the extracellular matrix (ECM) 1 . This can be injected into the damaged heart tissue via a catheter, forming a structure in damaged areas of heart tissue, assisting in new cell growth and cell repair 1 . However, this hydrogel needed to be injected directly into the heart as well as using the hydrogel only one week or more after a heart attack – due to needle-based injection procedures, this caused a risk of damage 1 . This biomaterial was tested, and it has effectively treated tissue damage caused by heart attacks in rodents and large animals 1 . Initial proof of concept in rodent models strongly suggests that the biomaterial could potentially be beneficial to patients with traumatic brain injury and pulmonary arterial hypertension 1 . Christman stated that studies to test the safety and efficiency of the biomaterial on human subjects could start within one or two years 1 .
In the USA, approximately 785,000 new heart attack cases arise every year 1 . When a person recovers from a heart attack, they are left with scar tissue and muscle function decline leading to congestive heart failure. Currently, there are no treatments for repairing cardiac tissue damage 1 .
How is this biomaterial created?
Initially, researchers in Christman’s laboratory used hydrogel they developed that enabled intravenous injections as part of safety trials 1 . However, the hydrogel particles were too large to target leaky blood vessels, this was resolved by a PhD student Sprang by centrifuging the hydrogel particles into nanoparticle size 1 . The liquid ECM hydrogel was centrifuged at 15,000 RCF at 4°C for 45 minutes, which separated the bigger-sized particles away to extract only the nano-size particles 1,2 . After centrifuging, the supernatant iECM (infusible ECM) was out through dialysis, then sterile filtering, and finally, freeze-dried 1,2 .
How does this biomaterial work?
Patches of decellularised extracellular matrix and locally injected hydrogels have been used as therapies in animal models of disease 2 .
Instead, the biomaterial bound to the endothelial cells forces the gap to close and increases the speed of healing in blood vessels 1 . This helped reduce inflammation, equivalent results occurred when researchers tested the biomaterial on porcine models of heart attack 1 . Various assays were performed to comply with evidence, and iECM was found to be haemocompatible – meaning being compatible in the presence of blood. This was tested using 1:1 iECM to human blood and physiological concentrations of 1:10 iECM, with immediate dilution with blood, then infusion 2 . As a result, Prothrombin times, RBC aggregation, and Platelets aggregation with agonists were within the physiological ranges 2 . IECM has been shown to bind to inflamed endothelium, reduce vascular leakages and increase vascular healing 1,2 .
Figure 1: The biomaterial is based on the hydrogel that was produced in Christman’s laboratory 1,3 .
For the future?
Christman and Ventri Bio, Inc., are now amid seeking FDA approval to conduct a study on human hearts of the biomaterial’s applications in heart conditions 1 .
References
1. Patringenaru, I. (2023). This Injectable Biomaterial Heals Tissues From the Inside Out . UC San Diego Today. https://today.ucsd.edu/story/this-groundbreaking-biomaterial-heals-tissues-from-the-inside-out#:~:text=The%20biomaterial%20was%20tested%20and%20proven%20effective%20in,with%20traumatic%20brain%20injury%20and%20pulmonary%20arterial%20hypertension
2. Spang, M. T., Middleton, R., Diaz, M., Hunter, J., Mesfin, J., Banka, A., Sullivan, H., Wang, R., Lazerson, T. S., Bhatia, S., Corbitt, J., D’Elia, G., Sandoval-Gomez, G., Kandell, R., Vratsanos, M. A., Gnanasekaran, K., Kato, T., Igata, S., Luo, C., . . . Christman, K. L. (2022). Intravascularly infused extracellular matrix as a biomaterial for targeting and treating inflamed tissues. Nature Biomedical Engineering . https://doi.org/10.1038/s41551-022-00964-5
3. University of California - San Diego. (2023). This groundbreaking biomaterial heals tissues from the inside out . ScienceDaily. Retrieved 20th February 2023 from www.sciencedaily.com/releases/2023/01/230130144805.htm