Gopal Anyarambhatla

Enhancement of the Phase Transition Permeability of DPPC Liposomes by Incorporation of MPPC: A New Temperature-Sensitive Liposome for use with Mild Hyperthermia

AbstractThe present study describes a novel method of preparing thermosensitive liposomes by compositional modification, incorporating a highly bilayer compatible lysolipid, 1 -Palmitoyl-2-Hydroxy-sn-Glycero-3-Phosphocholine (MPPC) into the gel phase liposomes composed of l,2-Dipalmitoyl-sn-Glycero-3-Phosphocholine (DPPC). This compositional modification of the liposomes achieved a significantly enhanced release of entrapped liposome contents at mild hyperthermic temperatures between 39°C-40°C as compared to pure DPPC which released only 20% of contents over a broader range of 40°C-45°C, and the more conventional (DPPC/DSPC-based) temperature-sensitive liposomes that released more slowly in the 43°C-45°C range. Also, the temperature range over which the maximum release occurred for the DPPC:MPPC system remained very narrow and maximum release is achieved after only a tens of seconds of heating. Characterization of the liposome formulation was carried out by studying the release profiles of entrapped carbo...