Pharmacy Department, Faculty of Technology & Engineering, The Maharaja Sayajirao University of Baroda, Post Box No.: 51, Kalabhavan, Vadodara 390 001, Gujarat state, India.
Biomaterials. 2012 Mar;33(8):2492-507. doi: 10.1016/j.biomaterials.2011.11.067. Epub 2011 Dec 24.
The objective of present investigation was to develop and assess comparative enhancement in cytotoxicity of liposomal Etoposide and Docetaxel in non-small cell lung cancer cell lines after pre-treatment and co-administration of p53 tumor suppressor gene and to assess direct lung targeting of optimized formulations by dry powder inhaler technology. Cationic liposomes with and without drug were prepared and allowed to form p53-lipoplex for undertaking cytotoxicity studies in H-1299 (p53 null) and A-549 (p53 wt) cell lines. The optimized lipoplexes showed average size of 200-350 nm, zeta potential of 25-32 mV and sustained drug release up to 16-24 h. The developed liposomes and lipoplexes showed significant intracellular uptake and demonstrated enhanced cytotoxicity of 13-28 % after p53-drug co-administration and 41-63 % after p53 pre-treatment. The p53 mediated enhanced cytotoxicity by increased apoptosis and necrosis was also confirmed using Annexin V - FITC assay. The increased apoptosis suggested restored p53 function and reduced anti-apoptotic drug resistance theirby causing cell sensitization and synergism towards cytotoxicity. The studies conducted above demonstrated significant cell chemo-sensitization after p53 pre-treatment followed by Etoposide/Docetaxel liposomes administration than p53-Etoposide or p53-Docetaxel lipoplex co-administration; more significantly in Docetaxel and in H 1299 cell line. All the formulations when developed as dry powder inhalers showed significant in vitro lung deposition pattern in cascade impactor with fine particle faction of 33-37%. The study opens up a new strategy to treat lung cancer especially in cases of drug resistance. Moreover direct delivery to lung may provide an important role in complete remission of the disease due to target specificity.
本研究旨在开发和评估在预处理和共给药 p53 肿瘤抑制基因后，脂质体依托泊苷和多西紫杉醇对非小细胞肺癌细胞系的细胞毒性的增强作用，并通过干粉吸入器技术评估优化配方的直接肺部靶向作用。制备了载药和未载药的阳离子脂质体，并使其形成 p53-脂质体复合物，以在 H-1299（p53 缺失）和 A-549（p53 wt）细胞系中进行细胞毒性研究。优化的脂质体的平均粒径为 200-350nm，zeta 电位为 25-32mV，药物持续释放时间长达 16-24 小时。所开发的脂质体和脂质复合物表现出明显的细胞内摄取，并在 p53-药物共给药后显示出 13-28%的增强细胞毒性，在 p53 预处理后显示出 41-63%的增强细胞毒性。使用 Annexin V-FITC 测定法还证实了 p53 介导的增强细胞毒性通过增加凋亡和坏死来实现。增加的凋亡表明恢复了 p53 功能并降低了抗凋亡药物耐药性，从而导致细胞对细胞毒性的敏感性和协同作用。上述研究表明，与 p53-Etoposide 或 p53-Docetaxel 脂质复合物共给药相比，p53 预处理后给予依托泊苷/多西紫杉醇脂质体给药可显著增强细胞化学敏感性，尤其是在多西紫杉醇和 H1299 细胞系中。所有制剂均开发为干粉吸入剂，在级联撞击器中显示出显著的体外肺部沉积模式，其中细颗粒分数为 33-37%。该研究为治疗肺癌，特别是在耐药情况下，开辟了一条新的策略。此外，由于靶向特异性，直接向肺部给药可能在疾病的完全缓解中发挥重要作用。
