Influence of archaeal lipids isolated from Aeropyrum pernix K1 on physicochemical properties of sphingomyelin-cholesterol liposomes

We investigated the influence of archaeal lipids (C_25,25) isolated from thermophilic archaeon Aeropyrum pernix K1 on physicochemical properties of liposomes comprised of egg sphingomyelin (SM) and cholesterol (CH) using fluorescence emission anisotropy, calcein release studies, dynamic light scattering, transmission electron microscopy and phase analysis light scattering. The 2 mol% addition of archaeal lipids enabled formation of small unilamellar vesicles by sonication while also having significant effect on reducing mean size, polydispersity index and zeta potential of C_25,25/SM/CH vesicles. Increasing the ratio of C_25,25 lipids in mixture of C_25,25/SM/CH decreased lipid ordering parameter in dose dependent manner at different temperatures. We also demonstrated that adding 15 mol% C_25,25 to SM/CH mixture will cause it to notably interact with fetal bovine serum which could make them a viable alternative adjuvant to synthetic ether-linked lipids in development of advanced liposomal vaccine delivery systems. The prospect of combining the proven strengths of SM/CH mixtures with the unique properties of C_25,25 opens exciting possibilities for advancing drug delivery technologies, promising to yield formulations that are both highly effective and adaptable to a range of therapeutic applications.