Photo: University of Sydney
Saving gravely wounded patients from hemorrhaging can be key to saving their lives.
An injury to just an arm or leg can be fatal within minutes if someone is hemorrhaging without treatment.
However, in many situations it can be difficult, even for doctors, to stop the bleeding long enough to save a patient.
An injury to the delicate tissue of an artery or to a major organ can be difficult to repair.
In remote areas or on the battlefield, it can be difficult to get people who are bleeding into an operating room quick enough to save their life.
As a result, a group of scientists are hoping to save lives by developing a new type of surgical sealant that can be affixed even to delicate tissues.
Devising a surgical sealant
In a new study published in Science Translational Medicine, scientists from Harvard University, Northeastern University, and other institutions, wanted to see if they could utilize a natural human protein called tropoelastin to find a way to make a better surgical sealant.
The team examined how the sealant performed in animal tissue.
Nasim Annabi, a lead study author as well as an assistant professor at the Department of Chemical Engineering at Northeastern University and a lecturer at Harvard-MIT’s Division of Health Sciences and Technology, said that after talking to pulmonologists the team realized the need for a new kind of surgical sealant.
“We became aware that lung injuries in particular pose a surgical problem for which there is no convincing solution yet, and started to investigate our materials approach as a sealant for lung and other elastic tissues,” Annabi said in a statement.
Tropoelastin helps the body create elastin, which is key for the lungs, joints, and other parts of the body.
The team was able to use the tropoelastin in a process that also involved UV light to create a “crosslinked” gel they called MeTro, short for methacryloyl-substituted tropoelastin.
The hope for MeTro was to create a surgical sealant that can be applied without additional sutures or staples.
“Currently available sealants are not suitable for most surgical applications and they do not work alone without the need for suturing or stapling because they lack an optimal combination of elasticity, tissue adhesion, and strength,” said Ali Khademhosseini, PhD, a study co-author and an associate faculty member at Harvard’s Wyss Institute for Biologically Inspired Engineering, in a statement. “Using our expertise in creating materials for regenerative medicine, we aimed to create an actual fix for this problem.”
Testing the sealant
The team tested the material in the lungs and arteries of rats and found it effectively sealed them.
They also tested the substances in leaking lungs in pigs.
The researchers found that they were able to completely seal the wound without additional sutures or staples, and that there was no sign of pneumothorax or collapsed lung during a 14-day follow-up of the pigs.
“In our in vivo studies, MeTro seems to remain stable over the period that wounds need to heal in demanding mechanical conditions and later it degrades without any signs of toxicity,” said Khademhosseini in a statement. “It checks off all the boxes of a highly versatile and efficient surgical sealant with potential also beyond pulmonary and vascular suture and staple-less applications.”
Dr. Robert Glatter, an emergency physician at Lenox Hill Hospital in New York, said there’s a need for a better sealant to help patients.
“In the setting of the emergency department, anything that is less invasive or a time saver is something that would be valuable to us,” he said.
He also said doctors can do sutures quickly, including a figure eight stitch, to stop bleeding for certain wounds, but that can lead to “tissue injury or disfigurement in the long term.”
Glatter said this study was “very promising” even though it’s preliminary.
“This kind of product would be ideal certainly to coagulate or promote the coagulation cascade and stop the bleeding,” he said.
He also added that the fact that the sealant is “part of a naturally [occurring] part of our body” is helpful since it’s “not toxic.”