The transportation of large biomolecules across cell membranes poses a significant challenge. To overcome this hurdle and effectively deliver hydrophilic substances like pharmaceuticals into cells, researchers from the University of Santiago de Compostela’s Center for Research in Biological Chemistry and Molecular Materials (CiQUS) collaborated with a team from the Universidade Nova de Lisboa (NOVA) to develop novel light-responsive membrane transporters.
The scientists employed calixarene-based receptors equipped with azobenzene units, which act as photoresponsive counterions. By utilizing these counterions, they were able to exert precise control over the transport of cationic peptides. Counterions are oppositely charged ions that are attracted to the charged compound, forming charge-neutralized complexes that possess enhanced membrane permeability in this particular context.
When subjected to light irradiation, the azobenzene units undergo a conformational change, transitioning from a more polar to a more hydrophobic state. This transformation enables the counterions to traverse the cell membrane and enter the cytosol successfully. Dr. Nuno Basílio, a researcher at NOVA and co-author of the study recently published in the Journal of the American Chemical Society (JACS), explained that the ability to dynamically control the structure and polarity of counterion activators using light represents a promising conceptual strategy for the development of stimuli-responsive membrane carriers.
The synthesis of these molecular photoswitches demonstrates their potential for the light-triggered delivery of large biomolecules and opens up new avenues for remotely controlled systems in pharmaceutical applications, according to the authors.
Source: Center for Research in Biological Chemistry and Molecular Materials (CiQUS)