Various amounts of Ovalbumin (OVA) were encapsulated into positively and negatively charged multilamellar liposomes, with the aim to investigate the entrapment efficiency in different buffers and to study their effects on the liposome size and zeta potential. Results showed that the entrapment efficiency of OVA in anionic liposomes was the same in 10 mM Phosphate Buffer (PB) as in Phosphate-Buffered Saline (PBS; PB + 0.15 M NaCl). Also, liposome size was approximately 1200 nm for all anionic liposomes incorporating OVA. The entrapment efficiency of OVA in cationic liposomes was highly dependent on ionic strength. The size of cationic liposomes was approximately 1200 nm in PBS, regardless of protein content, but increased with the amount of the incorporated protein in PB. Aggregation of cationic liposomes in PB was observed when the mass of the protein was 2.5 mg or greater. The zeta potential of anionic liposomes was negative and of cationic liposomes positive in the whole range of protein mass tested. These results show how different compositions of lipid and aqueous phases can be used to vary the entrapment efficiency, liposome size, and zeta potential—the factors that are of great importance for the use of liposomes as drug carriers.

中文翻译：

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卵清蛋白包埋到脂质体中——影响包埋效率、脂质体大小和 Zeta 电位的因素

将不同量的卵清蛋白 (OVA) 封装到带正电荷和带负电荷的多层脂质体中，目的是研究不同缓冲液中的包封效率，并研究它们对脂质体大小和 zeta 电位的影响。结果表明，OVA 在阴离子脂质体中的截留效率在 10 mM 磷酸盐缓冲液 (PB) 中与在磷酸盐缓冲盐水 (PBS; PB + 0.15 M NaCl) 中相同。此外，所有包含 OVA 的阴离子脂质体的脂质体大小约为 1200 nm。OVA 在阳离子脂质体中的包埋效率高度依赖于离子强度。无论蛋白质含量如何，PBS 中阳离子脂质体的大小约为 1200 nm，但随着 PB 中掺入蛋白质的量而增加。当蛋白质质量为 2.5 mg 或更大时，观察到 PB 中阳离子脂质体的聚集。在测试的整个蛋白质质量范围内，阴离子脂质体的 zeta 电位为负值，而阳离子脂质体的 zeta 电位为正值。这些结果显示了如何使用不同的脂质和水相组成来改变包封效率、脂质体大小和 zeta 电位——这些因素对于使用脂质体作为药物载体非常重要。