Association and release of prostaglandin E1 from liposomes.

摘要: Abstract PGE1–lipid interactions were studied in several liposome systems. Data from both circular dichroic (CD) measurements and differential scanning calorimetry (DSC) indicated that PGE1 the protonated form seeks less polar environment of lipid bilayer. CD made on solution showed wavelength maximum absorbance red shifted approximately 8 nm with decreasing solvent polarity. The spectrum liposomal prepared pH 4.5 but not 7.2 buffer was also shifted. There no shift detected at absence phospholipid. DSC DSPC bilayers 5 mol% revealed an almost complete loss pre-transition as well broadening main phase transition. amount 3H-PGE1 initially associated EPC, POPC or liposomes determined using size exclusion filters centrifugation. This found to be dependent (pH 4.5≫pH 7.2) fluidity bilayer (EPC=POPC>DSPC), independent lamellarity liposome. In all cases, addition cholesterol reduced time-dependent release by rapidly diluting sample 100-fold into buffer. Lipid saturation a key factor influencing this release. Gel-phase rapid initial (t1/2