Isoliquiritigenin (ILQ) has a number of biological activities such as antitumor and anti-inflammatory effects. However, biomedical applications of ILQ are impeded by its poor aqueous solubility. Therefore, in this research, we prepared a novel ILQ-loaded nanoemulsion, i.e., ILQ-NE, which consisted of Labrafil^® M 1944 CS (oil), Cremophor^® EL (surfactant), ILQ, and phosphate-buffered saline, by employing a combined sonication (high-energy) and phase-inversion composition (low-energy) method (denoted as the SPIC method). The ILQ-NE increased the ILQ solubility ~1000 times more than its intrinsic solubility. It contained spherical droplets with a mean diameter of 44.10 ± 0.28 nm and a narrow size distribution. The ILQ loading capacity was 4%. The droplet size of ILQ-NE remained unchanged during storage at 4 °C for 56 days. Nanoemulsion encapsulation effectively prevented ILQ from degradation under ultraviolet light irradiation, and enhanced the ILQ in vitro release rate. In addition, ILQ-NE showed higher cellular uptake and superior cytotoxicity to 4T1 cancer cells compared with free ILQ formulations. In conclusion, ILQ-NE may facilitate the biomedical application of ILQ, and the SPIC method presents an attractive avenue for bridging the merits and eliminating the shortcomings of traditional high-energy methods and low-energy methods.

中文翻译：

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联合超声和相转化组合法制备异甘草素纳米乳：体外抗癌活性

异甘草素 (ILQ) 具有许多生物活性，例如抗肿瘤和抗炎作用。然而，ILQ 的生物医学应用因其水溶性差而受到阻碍。因此，在本研究中，我们制备了一种新型负载 ILQ 的纳米乳液，即 ILQ-NE，它由 Labrafil ^® M 1944 CS（油）、Cremophor ^®组成。EL（表面活性剂）、ILQ 和磷酸盐缓冲盐水，采用组合的超声处理（高能）和相转化组合物（低能）方法（表示为 SPIC 方法）。ILQ-NE 将 ILQ 溶解度提高到其固有溶解度的 1000 倍以上。它包含平均直径为 44.10 ± 0.28 nm 和窄尺寸分布的球形液滴。ILQ 负载能力为 4%。ILQ-NE 的液滴大小在 4 °C 储存 56 天期间保持不变。纳米乳液的包封有效地防止了ILQ在紫外光照射下的降解，提高了ILQ的体外释放率。此外，与游离 ILQ 制剂相比，ILQ-NE 对 4T1 癌细胞具有更高的细胞摄取和更高的细胞毒性。总之，ILQ-NE 可以促进 ILQ 的生物医学应用，