目的 探究磷脂種類對吲哚菁綠（ICG）脂質體制劑學性質的影響。方法 采用薄膜水化擠出法分別制備以氫化大豆卵磷脂（HSPC）、蛋黃卵磷脂為脂質成分的脂質體（ICG-H-Lipo、ICG-E-Lipo）。采用Zetasizer3000HS粒徑儀測定脂質體的粒徑、聚合物分散性指數（PDI）和Zeta電位；透射電子顯微鏡觀察脂質體形態(tài)；超濾離心法分別測定ICG-H-Lipo和ICG-E-Lipo的包封率。用紫外分光光度計分別測定ICG-E-Lipo、ICG-H-Lipo及游離ICG在400～1 000 nm的紫外吸收光譜。以粒徑變化為指標，考察脂質體用純水稀釋10倍、4℃條件下儲存1個月的長期穩(wěn)定性，考察脂質體在模擬血漿（pH 7.4大鼠血漿）中的穩(wěn)定性，考察脂質體用純水稀釋10倍后給予808 nm激光輻照（1 w·cm^-2、5 min）7 d內穩(wěn)定性；將ICG-HLipo、ICG-E-Lipo和游離ICG 4℃避光保存，分別于0、1、3、5、7 d檢測ICG在780 nm處的吸光度（A）值。將ICG-ELipo、ICG-H-Lipo和游離ICG配制成ICG質量濃度為25 μg·mL^-1的溶液，給予1 w·cm^-2、808 nm激光輻照5 min，用紅外熱像儀記錄溫度變化；給予5個808 nm激光開-關輻照（1 w·cm^-2，開5 min，關15 min），用紅外熱成像儀記錄溫度變化；采用1 w·cm^-2、808 nm激光分別輻照0、1、2、3、4 min，用紫外分光光度計檢測A值變化；以評價不同制劑的光熱效率。結果 成功制備了ICG-H-Lipo和ICG-E-Lipo，粒徑分布均勻，ICG的包封率分別為77.97%和70.67%。ICG-E-Lipo、ICG-H-Lipo均在895 nm處出現了強吸收峰，相比于游離ICG，ICG-E-Lipo、ICG-H-Lipo均發(fā)生了明顯紅移。穩(wěn)定性結果表明，ICG-H-Lipo和ICG-E-Lipo在去離子水、血漿溶液中及激光照射后粒徑沒有明顯變化；儲存7 d后的紫外吸收光譜圖顯示，ICG-E-Lipo和ICG-H-Lipo具有比游離ICG更好的穩(wěn)定性（P＜0.05、0.001） ，且ICG-H-Lipo中的ICG穩(wěn)定性最好。經過808 nm激光輻照5 min后，ICG-E-Lipo、ICG-H-Lipo、游離ICG的溫度均能達到腫瘤細胞的死亡溫度；在5次激光開-關循環(huán)照射后，ICG-H-Lipo的產熱效率相對穩(wěn)定，而ICG-E-Lipo略有下降，游離ICG的產熱效率下降了64%；激光照射4 min后的紫外吸收光譜圖表明，游離ICG發(fā)生嚴重的光漂白現象，ICG脂質體吸收峰下降較緩慢。結論 脂質體能顯著改善ICG的穩(wěn)定性；ICG脂質體的制劑學性質與磷脂種類密切相關；相同處方下，與蛋黃卵磷脂相比，HSPC制備的ICG脂質體具有更好的穩(wěn)定性和光熱性能。

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

國家自然科學基金項目（82003675）；安徽中醫(yī)藥大學培育項目（2020py04；2021py05）；安徽省高?？茖W研究項目（KJ2020A0429）