目的 探究磷脂种类对吲哚菁绿（ICG）脂质体制剂学性质的影响。方法 采用薄膜水化挤出法分别制备以氢化大豆卵磷脂（HSPC）、蛋黄卵磷脂为脂质成分的脂质体（ICG-H-Lipo、ICG-E-Lipo）。采用Zetasizer3000HS粒径仪测定脂质体的粒径、聚合物分散性指数（PDI）和Zeta电位；透射电子显微镜观察脂质体形态；超滤离心法分别测定ICG-H-Lipo和ICG-E-Lipo的包封率。用紫外分光光度计分别测定ICG-E-Lipo、ICG-H-Lipo及游离ICG在400～1 000 nm的紫外吸收光谱。以粒径变化为指标，考察脂质体用纯水稀释10倍、4℃条件下储存1个月的长期稳定性，考察脂质体在模拟血浆（pH 7.4大鼠血浆）中的稳定性，考察脂质体用纯水稀释10倍后给予808 nm激光辐照（1 w·cm^-2、5 min）7 d内稳定性；将ICG-HLipo、ICG-E-Lipo和游离ICG 4℃避光保存，分别于0、1、3、5、7 d检测ICG在780 nm处的吸光度（A）值。将ICG-ELipo、ICG-H-Lipo和游离ICG配制成ICG质量浓度为25 μg·mL^-1的溶液，给予1 w·cm^-2、808 nm激光辐照5 min，用红外热像仪记录温度变化；给予5个808 nm激光开-关辐照（1 w·cm^-2，开5 min，关15 min），用红外热成像仪记录温度变化；采用1 w·cm^-2、808 nm激光分别辐照0、1、2、3、4 min，用紫外分光光度计检测A值变化；以评价不同制剂的光热效率。结果 成功制备了ICG-H-Lipo和ICG-E-Lipo，粒径分布均匀，ICG的包封率分别为77.97%和70.67%。ICG-E-Lipo、ICG-H-Lipo均在895 nm处出现了强吸收峰，相比于游离ICG，ICG-E-Lipo、ICG-H-Lipo均发生了明显红移。稳定性结果表明，ICG-H-Lipo和ICG-E-Lipo在去离子水、血浆溶液中及激光照射后粒径没有明显变化；储存7 d后的紫外吸收光谱图显示，ICG-E-Lipo和ICG-H-Lipo具有比游离ICG更好的稳定性（P＜0.05、0.001） ，且ICG-H-Lipo中的ICG稳定性最好。经过808 nm激光辐照5 min后，ICG-E-Lipo、ICG-H-Lipo、游离ICG的温度均能达到肿瘤细胞的死亡温度；在5次激光开-关循环照射后，ICG-H-Lipo的产热效率相对稳定，而ICG-E-Lipo略有下降，游离ICG的产热效率下降了64%；激光照射4 min后的紫外吸收光谱图表明，游离ICG发生严重的光漂白现象，ICG脂质体吸收峰下降较缓慢。结论 脂质体能显著改善ICG的稳定性；ICG脂质体的制剂学性质与磷脂种类密切相关；相同处方下，与蛋黄卵磷脂相比，HSPC制备的ICG脂质体具有更好的稳定性和光热性能。

Objective To investigate the impact of phospholipid type on the pharmacological properties of indocyanine green (ICG) liposomes. Methods Liposomes (ICG-H-Lipo, ICG-E-Lipo) with hydrogenated soybean lecithin (HSPC) and egg yolk lecithin as lipid components were prepared by thin film hydration extrusion method. The particle size, polymer dispersion index (PDI) and Zeta potential of liposomes were measured by Zetasizer3000HS particle size analyzer. The morphology of liposomes was observed by transmission electron microscopy. The encapsulation efficiency of ICG-H-Lipo and ICG-E-Lipo were determined by ultrafiltration centrifugation. The ultraviolet absorption spectra of ICG-E-Lipo, ICG-H-Lipo and free ICG in the range of 400-1000 nm were determined by ultraviolet spectrophotometer. With the change of particle size as an index, the long-term stability of liposomes diluted with 10 times pure water and stored at 4 ℃ for 1 month was investigated, the stability of liposomes in simulated plasma (pH 7.4 rat plasma) was investigated, and the stability of liposomes diluted with 10 times pure water and irradiated with 808 nm laser (1 w·cmcm^-2, 5 min) within seven days was investigated. ICG-H-Lipo, ICG-E-Lipo and free ICG were stored in dark at 4 ℃, and the absorbance (A) value of ICG at 780 nm was measured at 0, 1, 3, 5 and 7 days respectively. In order to evaluate the photothermal efficiency of different preparations, ICG-E-Lipo, ICG-H-Lipo and free ICG were prepared into ICG with a mass concentration of 25 μg·mL^-1 solution, irradiated with 1 w·cmcm^-2, 808 nm laser for 5 min, and recorded the temperature change with infrared thermal imager. Give five 808 nm laser on-off irradiation (1 w·cmcm^-2, on 5 min, off 15 min), and record the temperature change with infrared thermal imager. Irradiate 1 w·cmcm^-2 and 808 nm laser for 0, 1, 2, 3 and 4 min respectively, and detect the change of A value with ultraviolet spectrophotometer. Results ICG-H-Lipo and ICG-E-Lipo liposomes were successfully prepared by the thin film hydration and extrusion method, the ICG encapsulation of which were 77.97% and 70.67%, respectively. Both ICG-E-Lipo and ICGH-Lipo have strong absorption peaks at 895 nm. Compared with free ICG, ICG-E-Lipo and ICG-H-Lipo have significant redshift. The stability results demonstrated that both ICG-H-Lipo and ICG-E-Lipo possess desirable colloid stability in deionized water, plasma solution and after laser irradiation. Changes of UV absorption profiles after seven days storage revealed that ICG-H-Lipo and ICG-E-Lipo generated better ICG stability than free ICG (P< 0.05 and 0.001), and ICG-H-Lipo possessed the best ICG stability. After irradiation of five on-off cycles, the heat production efficiency of ICG-H-Lipo was relatively stable, while ICG-E-Lipo decreased slightly, and the free ICG generate a 64% decrease, indicating that the photothermal stability of ICG-H-Lipo was better than ICG-E-Lipo and free ICG. Furthermore, the UV absorption spectrum after 4 min laser irradiation exhibited that the free ICG underwent a severe photobleaching performance, while the absorption peak of ICG liposomes decreased slowly. Conclusion Liposome is able to significantly improve the stability and pharmaceutical properties of the encapsulated ICG, and these improved characteristics were highly related with phospholipid type. ICG liposome consisting of hydrogenated soy lecithin displayed a better storage stability and photothermal performance than the counterpart egg yolk lecithin-constructed liposome.

R943

国家自然科学基金项目（82003675）；安徽中医药大学培育项目（2020py04；2021py05）；安徽省高校科学研究项目（KJ2020A0429）