Bucheon, South Korea – A group of scientists at the Catholic University of Korea’s biomedical and chemical engineering department have developed a novel polyurethane hydrogel. They suggest that it might have medical applications.
The hydrogels were made from a waterborne polyurethane based on poly(eta-caprolactone) and aqueous polyethyleneimine (PEI) solution. The gel formation was triggered by atmospheric carbon dioxide with no need for any other catalysts or UV initiation.
The CO2 adsorbs onto the PEI, and ammonium cations form, facilitating the crosslinking reaction between PEI and the PU. The rate can be controlled by the addition of sodium hydrogencarbonate to increase the amount of CO2 present.
The resulting PU hydrogels are both tough and elastic, the team says, with a high tensile strength of 2.05MPa, and an elongation at break of almost 440%.
Importantly, they say, the hydrogels are both biocompatible and biodegradable, and have a high adhesion strength on the skin, and injectability because they are made in situ. They claim these properties mean they have potential in applications such as tissue adhesion barriers, wound dressings, artificial skin and injectable fillers.
The work has been published in the journal Macromolecular Rapid Communications.