Nanocompartments with a pH release system based on an engineered OmpF channel protein

Synthosomes are a subclass of Polymersomes with a block copolymer membrane (PMOXA–PDMS–PMOXA) and a modified embedded transmembrane channel protein which acts as a selective gate. A synthosome based pH release system functioning increasing the pH from 5 to 7 was developed by introducing six histidine mutations to the OmpF constriction site (OmpF 6His). The pH-dependent compound release (acridine orange, positively charged between 5 ≤ pH ≤ 7) has been found to be tuned by the constriction site electrostatics and size by local structural modifications.