5,10,15,20–Tetrakis(3–hydroxyphenyl)chlorin (mTHPC; temoporfin) is one of the most potent second-generation photosensitizers available today for the treatment of a variety of clinical disorders and has a unique capability of being activated at different wavelengths. However, due to its highly lipophilic nature, poor solubility in the aqueous media and poor bioavailability limits its application in anticancer therapies. To overcome these potential issues, we developed three different liposomal formulations with mTHPC encapsulated in hydrophobic milieu thus increasing the bioavailability of the drug. The prepared formulations were characterized in terms of hydrodynamic diameter, surface charge, encapsulation efficiency, and stability studies. The mean size of the liposomes was found to be in the nanoscale range (about 100 nm) with zeta potential ranging from -6.0 to -13.7 mV. mTHPC loaded liposomes were also evaluated for morphology using atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM). Data obtained from the hemocompatibility experiments showed that these formulations were compatible with blood showing less than 10% hemolysis and coagulation time lower than 40 s. The results obtained from the single-cell gel electrophoresis assay also demonstrated no incidence of genotoxicity. Photodynamic destruction of SK-OV-3 cells using mTHPC loaded liposomes showed a dose-response relationship upon irradiation with two different wavelength lights (blue λ=457 nm & red λ=652 nm). A 10-fold pronounced effect was produced when liposomal formulations were irradiated at 652 nm as compared to 457 nm. This was also evaluated by the quantitative assessment of reactive oxygen production (ROS) using fluorescence microscopy. The qualitative assessment of PDT pre- and post-irradiation was visualized using confocal laser scanning microscopy (CLSM) which demonstrated an intense localization of mTHPC liposomes in the perinuclear region. Chick chorioallantoic membrane assay (CAM) was used as an alternative in-ovo model to demonstrate the localized destruction of tumor microvasculature. Overall, the prepared nanoformulation is a biocompatible, efficient and well characterized delivery system for mTHPC for the safe and effective PDT.

5,10,15,20–四（3-羟基苯基）二氢卟酚（mTHPC；替莫泊芬）是当今可用的最有效的第二代光敏剂之一，可用于治疗多种临床疾病，并具有独特的活化能力不同的波长。然而，由于其高度亲脂性，其在水性介质中的溶解性差和生物利用度差，限制了其在抗癌治疗中的应用。为了克服这些潜在的问题，我们开发了三种不同的脂质体制剂，其中的mTHPC封装在疏水性环境中，从而提高了药物的生物利用度。所制备的制剂通过流体动力学直径，表面电荷，包封效率和稳定性研究来表征。发现脂质体的平均大小在纳米级范围内（约100nm），ζ电势为-6.0至-13.7mV。还使用原子力显微镜（AFM）和低温透射电子显微镜（cryo-TEM）评估了装载mTHPC的脂质体的形态。从血液相容性实验中获得的数据表明，这些制剂与血液相容，表现出小于10％的溶血和小于40 s的凝结时间。从单细胞凝胶电泳分析获得的结果也证明没有遗传毒性发生。使用载有mTHPC的脂质体对SK-OV-3细胞的光动力破坏显示了在用两种不同波长的光（蓝色λ= 457 nm和红色λ= 652 nm）照射时的剂量反应关系。与457 nm相比，在652 nm处照射脂质体制剂时，产生了10倍的显着效果。这也通过使用荧光显微镜对活性氧产生（ROS）的定量评估进行了评估。使用共聚焦激光扫描显微镜（CLSM）可视化对PDT辐照前后的定性评估，结果表明mTHPC脂质体在核周区域中强烈定位。小鸡绒膜尿囊膜测定（CAM）被用作替代 使用共聚焦激光扫描显微镜（CLSM）可视化对PDT辐照前后的定性评估，结果表明mTHPC脂质体在核周区域中强烈定位。小鸡绒膜尿囊膜测定（CAM）被用作替代 使用共聚焦激光扫描显微镜（CLSM）可视化对PDT辐照前后的定性评估，结果表明mTHPC脂质体在核周区域中强烈定位。小鸡绒膜尿囊膜测定（CAM）被用作替代卵内模型来证明肿瘤微脉管系统的局部破坏。总体而言，所制备的纳米制剂是用于mTHPC的生物相容性，高效且特征明确的输送系统，用于安全有效的PDT。