Some marine plankton called dinoflagellates emit light in response to the movement of surrounding water, resulting in a phenomenon called milky seas or sea sparkle. The underlying concept, a shear‐stress induced permeabilisation of biocatalytic reaction compartments, is transferred to polymer‐based nanoreactors. Amphiphilic block copolymers that carry nucleobases in their hydrophobic block are self‐assembled into polymersomes. The membrane of the vesicles can be transiently switched between an impermeable to a semipermeble state by shear forces occurring in flow or during turbulent mixing of polymersome dispersions. Nucleobase pairs in the hydrophobic leaflet separate when mechanical force is applied, exposing their hydrogen bonding motifs and therefore making the membrane less hydrophobic and more permeable for water soluble compounds. This polarity switch is used to release payload of the polymersomes on demand, and to activate biocatalytic reactions in the interior of the polymersomes, such as luminescence reactions or radical polymerizations catalysed by the enzyme horseradish peroxidase. Such bio‐inspired shear stress‑responsive nanoreactors have potential for applications ranging from gel‐formation on demand, to three‐dimensional inkjet printing, and shear‐stress triggered drug delivery.
- block copolymers
- mechanoresponsive materials
- bioinspired materials
Rifaie-Graham, O., Galensowske, N. F. B., Dean, C., Pollard, J., Balog, S., Gouveia, M. G., Chami, M., Vian, A., Amstad, E., Lattuada, M., & Bruns, N. (2020). Shear stress-responsive polymersome nanoreactors inspired by the marine bioluminescence of dinoflagellates. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202010099