Development of processing techniques for liposomes using membranes

在这项研究中，我们开发了一种简单而新颖的方法，通过将脂醇溶液透过Shirasu多孔玻璃(SPG)膜来制备脂质体，这是基于当脂醇溶液缓慢透过SPG膜时，脂醇溶液与水之间形成界面并在SPG膜表面相互混合的现象，从而降低了醇溶液的浓度，并诱导脂质体的自发形成。我们用这种方法成功地制备了100 nm单分散脂质体，分别用脂质-异丙醇(IPA)和脂质-乙醇(EtoH)溶液。此外，当以IPA为乙醇时，冻融处理的脂质体的尺寸明显增大，而当使用乙醇时，冻融处理的脂质体的尺寸不变。有趣的是，尽管没有观察到乙醇对脂质体的大小、单分散性等结构的影响，但乙醇仍然影响脂质体的性质，特别是膜的流动性。

In this study, we developed a facile and novel method for preparing liposomes simply by permeating lipid-alcohol solutions through Shirasu porous glass (SPG) membranes.This is based on the phenomenon in which an interface between a lipid-alcohol solution and water is formed and the two solutions mix with each other at the surface of an SPG membrane when the lipid-alcohol solution is slowly permeated through the membrane; this reduces the concentration of the alcohol solution and induces spontaneous formation of liposomes. We successfully prepared 100-nm monodispersed liposomes by this method using lipid-isopropyl alcohol (IPA) and lipid-ethanol (EtOH) solutions. Additionally, an increase in the liposome size was clearly observed in freezing-thawing treatment when IPA was used as the alcohol, whereas the liposome size was unchanged by freezing-thawing treatment when EtOH was used. It is interesting that the alcohol affected the liposome properties, in particular the membrane fluidity, even although no effect of the alcohol on the liposome structure, such as size, monodispersity, was observed.