Where bioengineering meets physical chemistry: elucidating design principles of ionic liquids for transdermal drug delivery
Eden E. L. Tanner, DPhil
Ionic liquids (ILs), which consist of anions and bulky, asymmetric organic cations that are liquid below 100 degree Celsius, have been used in a variety of contexts, including energy and battery applications, in catalysis, and in synthesis. Their popularity is due to a range of favorable properties such as low volatility, recyclability, and tuneability, meaning that structural changes in the ionic components result in different observed physicochemical properties. Recently, this solvent class has been employed in a biomedical context, where ILs such as choline geranate (Figure 1 a) and b)) have shown great promise in navigating biological barriers and acting as efficacious transdermal drug delivery agents, transporting large proteins such as insulin across the skin and into the bloodstream (Figure 1 c) and d)). However, there is currently limited information on the chemical origins of this transport enhancement. What makes an ionic liquid great at transdermal delivery?
In this talk I will focus on the use of physical chemistry principles and techniques such as 2D Nuclear Magnetic Resonance Spectroscopy and Fourier Transform Infrared Spectroscopy to elucidate design principles to answer this question, and, more broadly, to highlight the opportunities that lay at the intersection of physical chemistry and bioengineering.
Figure 1. a) Chemical structure of choline geranic acid-based ionic liquid (CAGE), b) physical appearance of CAGE, c) PBS-insulin delivered to porcine skin, and d) CAGE-insulin delivered to porcine skin.
Dr Eden Tanner completed her undergraduate studies as a Chemistry major at the University of New South Wales in Sydney, Australia working with Jason Harper. She continued on to complete a DPhil under the supervision of Richard Compton at the University of Oxford as a Clarendon Scholar in Physical and Theoretical Chemistry with a thesis titled “Nanoelectrochemistry in Room Temperature Ionic Liquids”. Currently, Eden is working with Samir Mitragotri at Harvard University on the application of ionic solvents to drug delivery. In the future, the Tanner lab will focus on the application of ionic solvents to solve outstanding challenges in nanoparticle drug delivery.