The most common complication after lung surgery is air leakage. Patients who experience air leaks after surgery may need a chest tube to drain the lung, which can put them at increased risk for infection, longer hospital stays and higher health care costs. Current synthetic sealants that have been approved by the Food and Drug Administration have drawbacks and limitations - some are complex to apply, others are elastic but don't adhere well in the dynamic environment of the lung. And no commercially available sealant has been approved for use without sutures or staples. A newly engineered material, developed and tested by researchers from Brigham and Women's Hospital and their collaborators at Northeastern University, Beth Israel Deaconess Medical Center and the University of Sydney, could become the first suture-less sealant for wound closure. In laboratory tests of the material, known as a MeTro sealant, the team demonstrated complete sealing of severely leaking lung tissue, as well as evidence that the material could help promote wound healing. Their results are published this week in Science Translational Medicine.
"A good surgical sealant needs to have a combination of characteristics: it needs to be elastic, adhesive, non-toxic and biocompatible," said lead author Nasim Annabi, PhD, who holds a joint appointment at Northeastern University and is a lecturer at BWH. Annabi is also affiliated with the Wyss Institute. "Most sealants on the market possess one or two of these characteristics, but not all of them. We set out to engineer a material that could have all of these properties."
MeTro is shorthand for methacryloyl-substituted tropoelastin - a protein derived from the elastic fibers that make up human tissue. Because the substance is laboratory-modified tissue rather than synthetic, it is much more biocompatible than other sealants. After a short exposure to light, it can form a highly elastic and adhesive layer on the wound. The research team tested the MeTro sealant in preclinical models, including rat and porcine models, finding that the sealant had no toxicity and controlled in vivo degradation. The team also found that the sealant provided higher tensile strength, elongation, and better adhesive strength and burst pressure resistance than several commercially available sealants. In previous work, the team found that the MeTro gel was an excellent candidate for regenerating tissue, meaning that it could potentially help to heal as well as seal incisions.
The team plans to launch the first phase of clinical trials in humans and will investigate other adhesion mechanisms for the MeTro sealant to guide the next-generation of its formulation.
Funding for this work was provided by the NIH (EB023052, AR057837, DE021468, D005865, AR068258, AR066193, EB022403, and EB021148) and the Office of Naval Research, Presidential Early Career Award for Scientists and Engineers, the NIH (EB014283), the Australian Research Council, and the National Health and Medical Research Council. N.A. acknowledges the support from the American Heart Association (16SDG31280010), FY17 TIER 1 Interdisciplinary Research Seed Grants from Northeastern University and a postdoctoral funding from the German Heart Foundation, Frankfurt, Germany.