Temperature and oxidation-sensitive dioleoylphosphatidylethanolamine liposome stabilized with poly(ethyleneimine)/(phenylthio)acetic acid ion pair

• Published in: Journal of biomaterials science. Polymer ed. Vol. 34; no. 5; pp. 632 - 649
• Main Authors: Zhao, Fanyu, Sharma, Garima, Kim, Jin-Chul
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01-04-2023; Taylor & Francis Ltd
• Subjects: (phenylthio)acetic acid; Acetic Acid; Dioleoylphosphatidylethanolamine; Hydrogen Peroxide; Hydrogen-Ion Concentration; Ions; Liposomes - chemistry; Oxidation; Phosphatidylethanolamines - chemistry; poly(ethylene imine); Spectroscopy, Fourier Transform Infrared; Temperature; oxidation; poly(ethylene imine); temperature; (phenylthio)acetic acid; Dioleoylphosphatidylethanolamine
• ISSN: 0920-5063; 1568-5624
• DOI: 10.1080/09205063.2022.2138693

Temperature and oxidation-sensitive liposomes were prepared by stabilizing dioleoylphosphatidylethanolamine (DOPE) bilayers with the ion pair of poly(ethyleneimine)/(phenylthio)acetic acid (PEI/PTA). An upper critical solution temperature (UCST) behavior was observed when PEI/PTA ion pair was suspended in an aqueous solution. It was observed that the UCST increased with increasing PTA content. The ion pair was self-assembled into nanospheres owing to its amphiphilic property which was confirmed by transmission electron microscopy. The FT-IR spectroscopic spectrum showed that the ion pair formed a salt bridge between the amino group and the carboxyl group and the PTA content in the ion pair was readily oxidized by H
2
O
2
. Further, DOPE liposomal membranes could be stabilized with PEI/PTA ion pair. Due to the amphiphilic property, the ion pair played a role as a stabilizer for the formation of DOPE liposomes. The liposome released its payload in a temperature-responsive manner, possibly because when the temperature is raised, the ion pair loses its amphiphilic property and can be detached from the liposomal membrane. The liposome was also oxidation-responsive in terms of release, possibly because the amphiphilic property of the ion pair disappears when the PTA is oxidized.
The schematic diagram of temperature and oxidation-sensitive DOPE liposome incorporating PEI/PTA ion pair.