Phase Behavior of Pure PSPC and PEGylated Multicomponent Lipid and Their Interaction with Paclitaxel: An All-Atom MD Study.

Exploring structural behavior of pure 1-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine (PSPC) and multicomponent PSPC and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N[amino(poly(ethylene glycol))-2000] (DSPE-PEG2000) membranes and their interaction with pharmaceutically important drugs carry huge importance in drug delivery. Using all-atom molecular dynamics (MD) simulations, we investigated the phase behavior of pure and PEGylated membranes at the temperature range of 280-360 K. We observe a gel-to-liquid crystalline phase transition for pure PSPC between 320 and 330 K, and in the case of multicomponent membranes, at 320 K, a coexistence of order-disorder phases is observed, which gradually transform to a complete liquid crystalline to gel phase between 320 and 310 K. We further studied the interaction of Paclitaxel with pure PSPC and PEGylated bilayers and elucidated the interaction behavior of Paclitaxel at the bilayer interfaces. Understanding of structural and interaction behaviors of the PEGylated bilayers with Paclitaxel will help to explore Paclitaxel-based drug applications in the future.