Currently, organic solvents are necessary for the preparation of anionic liposomes for siRNA delivery. The removal of organic solvent is time-consuming and the residual organic solvent is not only a hidden danger, but also affects the stability of anionic liposomes. Glycerol, which is physiologically compatible and does not need to be removed, is used to promote the dispersion of lipids and the formation of anionic liposomes. Additionally, the preparation process is simple and not time-consuming. The results showed that anionic liposomes, which were typically spherical with a particle size of 188.9 nm were successfully prepared with glycerol. And with the help of Ca2+ , siRNA was encapsulated in anionic liposomes. The highest encapsulation efficiency at 2.4 mM Ca2+ reached 91%. And the formation of calcium phosphate could promote the endosomal escape of siRNA effectively. The results from cell viability showed that the anionic liposomes had no obvious cytotoxicity. It was also verified that anionic liposomes could improve the resistance of siRNA against degradation. Additionally, siRNA delivered by anionic liposomes could play an effective role in knockout. Therefore, anionic liposomes prepared with glycerol will be a safe and effective delivery platform for siRNA and even other nucleic acid drugs.

中文翻译：

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无需有机溶剂制备的阴离子脂质体，可有效递送 siRNA。

目前，有机溶剂是制备用于 siRNA 递送的阴离子脂质体所必需的。有机溶剂的去除费时费力，残留的有机溶剂不仅是一种隐患，还会影响阴离子脂质体的稳定性。甘油具有生理相容性，不需要去除，用于促进脂质的分散和阴离子脂质体的形成。此外，制备过程简单且不费时。结果表明，用甘油成功制备了粒径为188.9 nm的典型球形阴离子脂质体。在 Ca2+ 的帮助下，siRNA 被包裹在阴离子脂质体中。在 2.4 mM Ca2+ 时的最高包封效率达到 91%。并且磷酸钙的形成可以有效促进siRNA的内体逃逸。细胞活力的结果表明阴离子脂质体没有明显的细胞毒性。还验证了阴离子脂质体可以提高siRNA的抗降解性。此外，阴离子脂质体递送的 siRNA 可在基因敲除中发挥有效作用。因此，用甘油制备的阴离子脂质体将成为siRNA乃至其他核酸药物安全有效的递送平台。