In recent years, patients with pulmonary emphysema have been increasing mainly among middle-aged and elderly males due to aging and excessive smoking. Emphysema makes brittle lungs, and in severe cases, holes develop in the lung tissue, causing air leakage. Researchers at NIMS developed a new sealant to close holes developed in lungs and blood vessels using Alaska pollock gelatin. In the paper published in the Journal of Biomedical Nanotechnology, they reported that the sealant is about 12 times stronger than conventional sealants and is able to resist pressure as high as approximately 2.8 times the normal blood pressure.
Furthermore, the researchers explain that the advantage of the sealant is its property of remaining liquid at room temperature as it contains gelatin extracted from Alaska pollock, which is a cold-water fish. “The sealant doesn’t have to be preheated before surgery, and it can be sprayed directly on an open wound after mixing it with a crosslinking agent. Because it possesses extremely high bonding strength and elasticity, and it slowly breaks down in the body after surgery, it has the potential to be used as a sealant for any organ.”
Currently, fibrin sealants, which contain blood-derived components, are mostly used as supplementary materials to seal holes developed in blood vessels and organs. However, their bonding strengths are lower than normal blood pressure and thus are inadequate, and their wet tissue adhesion is particularly weak.
To resolve this issue, the research group led by Tetsushi Taguchi
, who belongs to the MANA (International Center for Materials Nanoarchitectonics) Biomaterials Unit, had been developing a sealant using pig-derived gelatin. Taguchi explains that the key approach to increasing sealants’ bonding strength is the creation and use of hydrophobically-modified gelatin. “When gelatin is chemically modified with hydrophobic group, the hydrophobic group partially penetrates tissue in the manner in which a ship anchors itself to the seabed. Consequently, the use of hydrophobically-modified gelatin will improve sealants’ adhesion to biological tissues.” However, sealants using pig-derived gelatin still had a disadvantage: they need to be liquefied by heating before their use in surgery operation, since they become gelatinous when they are exposed to low temperatures or condensed.