Effects of Cremophor EL/ethanol/oleinic acid/water microemulsion on human blood components and coagulation function

Microemulsions have attracted great interest in the biomedical field involving drug delivery, skin treatment and immune-adjuvant. In any case, microemulsions administered in vivo will more or less contact blood tissue inevitably, however there is no specialized investigation on the interaction between microemulsions and human blood components at cellular and membrane levels. Herein we investigate the effect of a typical microemulsion formulation (Cremophor EL/ethanol/oleinic acid/water (CEOW-ME)) with different extent dilution on human blood components (red blood cells (RBCs), coagulation factor, plasma albumin) and blood coagulation function. It was found that CEOW-ME had a concentration dependent effect on blood components and displayed anti-coagulant activity, causing coagulation factor activation, platelet aggregation impairment and RBC morphology alteration, whereas no impacting on fibrinogen polymerization. Interestingly CEOW-ME had greater influence on the coagulation factors in the plasma related to intrinsic coagulation pathway than extrinsic coagulation pathway. Additionally, spectroscopy studies (DLS, UV-vis, Fluorescence and CD) demonstrated that the impact of CEOW-ME on the size, local micro-structure and conformation of albumin was mediated by hydrophobic binding-induced unfolding and disordering of hierarchical albumin structure. These findings give more comprehensive information for forecasting the potential interaction of the in vivo-administered microemulsions with the cells and bioactive molecules in the human blood.