College of Engineering | December 29, 2018
A study from the University of Notre Dame has found that the properties of a material commonly used to create conductive or protective films and encapsulate drug compounds – and the conditions in which this material will disassemble to release that medication – may be different than initially thought.
Published in the Journal of the American Chemical Society, the study aimed to identify the conditions under which polyelectrolyte complexes, or PECs, would assemble and stay assembled. The researchers found new, important differences between strong and weak PECs.
“The mechanism of weak PECs is completely different than that of strong PECs,” said Jonathan Whitmer, assistant professor in the Department of Chemical and Biomolecular Engineering (CBE) and principal investigator for the study. “During our research, we found that when each of the weak polyelectrolytes came together in a solution, the presence of an oppositely charged polymer resulted in a strong pKa shift, enabling both polyelectrolytes to become highly charged and to stay stable.” Whitmer continued, “On the contrary, pH has relatively little influence on the charge and assembly of strong PECs, whose strong binding to salt ions determines most of their assembly.”
Weak PECs have been studied for many uses, including as a material to create capsules that hold medications. Weak PECs have a unique ability to bond and release in certain environments, but Whitmer’s team found that pH affected the overall assembly of weak PECs, as well as the conditions in which these materials may release.
Read more here.