We studied the effects of emulsifiers on the entrapment yields of a hydrophilic material, calcein, in lipid vesicles formed using the multiple emulsion method. The primary emulsion (W₁/O) was prepared via sonication while the secondary emulsification that produced the W₁/O/W₂ multiple emulsions was achieved using the microchannel (MC) emulsification technique. The emulsifiers used in the continuous (W₂) phase were Tween® 80, Pluronic® F68, and bovine serum albumin (BSA). Lipid vesicles formed via solvent evaporation of the multiple emulsion droplets had an average diameter of about 180 nm, similar to the size of the water droplets in the primary W₁/O emulsions. The entrapment yields of calcein increased with decreasing concentrations of Tween® 80 but decreased with decreasing concentrations of Pluronic® F68 and BSA. The effects of type and concentration of emulsifier were considered in relation to three possible mechanisms: (i) destabilization/solubilization of lipid bilayers by emulsifiers, (ii) reversed‐micellar transport of W₁ contents from internal to external water phases through the O phase, and (iii) release of inner water (W₁) contents into the continuous (W₂) phase via the instability of W₁/O/W₂ and leakage of W₁ contents. Using the food grade emulsifier Tween® 80 at a low concentration of about 0.1 or 0.05 wt%, calcein as a model hydrophilic material could be efficiently entrapped (ca. 80%) in homogenously dispersed lipid vesicles.

中文翻译：

---

使用W / O / W多种乳液通过溶剂蒸发制备脂质囊泡：乳化剂对亲水性材料截留率的影响

我们研究了乳化剂对使用多重乳液法形成的脂质囊泡中亲水材料钙黄绿素的截留率的影响。通过超声处理制备初级乳液（W ₁ / O），而使用微通道（MC）乳化技术实现产生W ₁ / O / W ₂多重乳液的二次乳化。连续（W ₂）相中使用的乳化剂是Tween®80，Fluronic®F68和牛血清白蛋白（BSA）。通过溶剂蒸发多个乳化液滴形成的脂质囊泡的平均直径约为180 nm，与初级W _1中的液滴大小相似/ O乳液。钙黄绿素的包封率随Tween®80浓度的降低而增加，但随Pluronic®F68和BSA浓度的降低而降低。乳化剂的类型和浓度的影响与三种可能的机理有关：（i）乳化剂使脂质双层不稳定/增溶；（ii）W ₁含量从内相到外相通过O相反向胶束传输，和（iii）的内水释放（W ₁）内容物进入连续的（W ₂通过的不稳定性）相W ₁ / O / W ₂和W的泄漏₁内容。使用约0.1或0.05 wt％的低浓度食品级乳化剂Tween®80，可以将钙黄绿素作为模型亲水材料有效地捕获（约80％）在均匀分散的脂质囊泡中。