Molecular Design of Amphiphilic Plasma Membrane-Targeted Azobenzenes for Nongenetic Optical Stimulation

• Main Authors: Vito Vurro, Gaia Bondelli, Valentina Sesti, Francesco Lodola, Giuseppe Maria Paternò, Guglielmo Lanzani, Chiara Bertarelli
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-01-01
• Series: Frontiers in Materials
• Subjects: photochromic molecules; photostimulation; cell membrane; amphiphilic compounds; spectroscopy
• Online Access: https://www.frontiersin.org/articles/10.3389/fmats.2020.631567/full

We present a series of cationic membrane-targeted azobenzene molecules, with the aim to understand how variations in molecular architecture influence the relative optical and biological properties. 1,4-Amino-substituted azobenzene was chosen as the switching unit while the number of linked alkyl chains and their cationic end-group were systematically varied. Their photophysics, membrane partitioning, and electrophysiological efficacy were studied. We found that the polar end group is a key-factor determining the interaction with the phospholipid heads in the plasma membrane bilayer and consequently the ability to dimerize. The monosubstituted photoswitch with a pyridinium-terminated alkyl chain was found to be the best candidate for photostimulation. This study provides a structure-property investigation that can guide the chemical engineering of a new generation of molecular photo-actuators.