Investigation of Surface Behavior of DPP Cand Curcuminin Langmuir Monolayers at the Air-Water Interface

Langmuir monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and a mixture of DPPC with curcumin (CUR)have been investigated at the air-water interface through a combination of surface pressure measurements and atomic forcemicroscopy (AFM) observation. By analyzing the correlation data of mean molecular areas, the compressibility coefficient, andother thermodynamic parameters, we obtained that the interaction between the two components perhaps was mainly governed bythe hydrogen bonding between the amino group of DPPC and the hydroxyl groups of CUR. CUR markedly affected the surfacecompressibility, the thermodynamic stability, and the thermodynamic phase behaviors of mixed monolayers. The interactionbetween CUR and DPPC was sensitive to the components and the physical states of mixed monolayers under compression. Two-dimensional phase diagrams and interaction energies indicated that DPPC and CUR molecules were miscible in mixed monolayers.AFM images results were in agreement with these analyses results of experimental data. This study will encourage us to furtherresearch the application of CUR in the biomedical field.