In this study, the differential interaction mechanism of curcumin with the lipid/Chol monolayer (molar ratio 7:3) rich in electrically neutral PC groups and rich in negatively charged PS groups was revealed at the membrane level.
Using the Langmuir monolayer technique combined with atomic force microscopy, the effects of different concentrations of curcumin (22, 41, 253 ng/mL) on the surface pressure-mean molecular area isotherms, elastic modulus, relaxation time, and microscopic morphology of the two mixed monolayers were systematically studied.
The results showed that the interaction strength between curcumin and the POPS/Chol monolayer was significantly greater than that of the POPC/Chol monolayer, and the response pattern was quite different.
The AFM results further shown that curcumin may be adsorbed in the form of aggregates in POPC/Chol monolayer films, while no curcumin aggregates were observed in POPS/Chol monolayer films.
The above difference are most likely due to the negative charge of the PS head group and its high exposure on the surface of the monolayer, allowing curcumin to interact with it more strongly through ion-dipole interaction.This study revealed a new mechanism of curcumin’s anti-tumor selectivity at the level of the membrane and provided experimental evidence for designing curcumin delivery strategies targeting the characteristics of tumor membrane phospholipids.
In this study, the differential interaction mechanism of curcumin with the lipid/Chol monolayer (molar ratio 7:3) rich in electrically neutral PC groups and rich in negatively charged PS groups was revealed at the membrane level. Using the Langmuir monolayer technique combined with atomic force microscopy, the effects of different concentrations of curcumin (22, 41, 253 ng/mL) on the surface pressure-mean molecular area isotherms, elastic modulus, relaxation time, and microscopic morphology of the two mixed monolayers were systematically studied. The results showed that the interaction strength between curcumin and the POPS/Chol monolayer was significantly greater than that of the POPC/Chol monolayer, and the response pattern was quite different. The AFM results further shown that curcumin may be adsorbed in the form of aggregates in POPC/Chol monolayer films, while no curcumin aggregates were observed in POPS/Chol monolayer films. The above difference are most likely due to the negative charge of the PS head group and its high exposure on the surface of the monolayer, allowing curcumin to interact with it more strongly through ion-dipole interaction.This study revealed a new mechanism of curcumin’s anti-tumor selectivity at the level of the membrane and provided experimental evidence for designing curcumin delivery strategies targeting the characteristics of tumor membrane phospholipids.
