Scientists develop new biomaterial that can be injected intravenously

Scientists have developed new biomaterial that can be injected intravenously, reduces inflammation in tissue and that could be used to repair the damage to cardiac tissue resulting from heart attack

Scientists have developed a new biomaterial that can be injected intravenously, reduces inflammation in tissue and that could be used to repair the damage to cardiac tissue resulting from a heart attack.

The researchers at the University of California (UC) San Diego, US, also provided proof of concept in a rodent model that the biomaterial could be beneficial to patients with traumatic brain injury and pulmonary arterial hypertension, the study said.

The biomaterial was tested and proven effective in treating tissue damage caused by heart attacks in both rodent and large animal models, according to the study.

"This biomaterial allows for treating damaged tissue from the inside out," said Karen Christman, a professor at UC San Diego, and the lead researcher on the team that developed the material.

"It's a new approach to regenerative engineering," said Christman.

A study on the safety and efficacy of the biomaterial in human subjects could start within one to two years, Christman said.

The study is published in the journal Nature Biomedical Engineering.

After a heart attack, scar tissue develops, which diminishes muscle function and can lead to congestive heart failure. There is no established treatment for repairing the resulting damage to cardiac tissue that follows a heart attack.

"Coronary artery disease, acute myocardial infarction, and congestive heart failure continue to be the most burdensome public health problems affecting our society today," said Dr. Ryan R. Reeves, a physician in the UC San Diego Division of Cardiovascular Medicine.

"As an interventional cardiologist, who treats patients with coronary artery disease and congestive heart failure on a daily basis, I would love to have another therapy to improve patient outcomes and reduce debilitating symptoms," said Reeves.

The team wanted to develop a treatment that could be administered immediately after a heart attack. This meant developing a biomaterial that could be infused into a blood vessel in the heart at the same time as other treatments such as angioplasty or a stent, or injected intravenously, the study said.

"We sought to design a biomaterial therapy that could be delivered to difficult-to-access organs and tissues, and we came up with the method to take advantage of the bloodstream - the vessels that already supply blood to these organs and tissues," said Martin Spang, the paper's first author.

According to the study, one advantage of the new biomaterial is that it gets evenly distributed throughout damaged tissue, because it is infused or injected intravenously.

Researchers in Christman's lab started with the hydrogel they developed, which was proven to be compatible with blood injections as part of safety trials. But the particle size in the hydrogel was too big to target leaky blood vessels, the study said.

Spang, then a PhD student in Christman's lab, solved this issue by putting the liquid precursor of the hydrogel through a centrifuge, which allowed for sifting out bigger particles and keeping only nano-sized particles, the study said.

The resulting material was put through dialysis and sterile filtering before being freeze dried. Adding sterile water to the final powder results in a biomaterial that can be injected intravenously or infused into a coronary artery in the heart, the study said.

Researchers then tested the biomaterial on a rodent model of heart attacks. They expected the material to pass through the blood vessels and into the tissue because gaps develop between endothelial cells in blood vessels after a heart attack, the study said.

But something else happened.

The biomaterial bound to those cells, closing the gaps and accelerating healing of the blood vessels, reducing inflammation as a result. Researchers tested the biomaterial in a porcine model of heart attack as well, with similar results, the study said.

The team also successfully tested the hypothesis that the same biomaterial could help target other types of inflammation in rat models of traumatic brain injury and pulmonary arterial hypertension. Christman's lab will undertake several preclinical studies for these conditions, the study said.