Center for Post Graduate Studies and Research in Pharmaceutical Sciences, The Maharaja Sayajirao University of Baroda, Vadodara, India.
J Liposome Res. 2012 Jun;22(2):139-47. doi: 10.3109/08982104.2011.633266. Epub 2011 Dec 8.
Vincristine-sulfate-loaded liposomes were prepared with an aim to improve stability, reduce drug leakage during systemic circulation, and increase intracellular uptake. Liposomes were prepared by the thin-film hydration method, followed by coating with calcium phosphate, using the sequential addition approach. Prepared formulations were characterized for size, zeta potential, drug-entrapment efficiency, morphology by transmission electron microscopy (TEM), in vitro drug-release profile, and in vitro cell cytotoxicity study. Effect of formulation variables, such as drug:lipid ratio as well as nature and volume of hydration media, were found to affect drug entrapment, and the concentration of calcium chloride in coating was found to affect size and coating efficiency. Size, zeta potential, and TEM images confirmed that the liposomes were effectively coated with calcium phosphate. The calcium phosphate nanoshell exhibited pH-dependent drug release, showing significantly lower release at pH 7.4, compared to the release at pH 4.5, which is the pH of the tumor interstitium. The in vitro cytotoxicity study done on the lung cancer cell line indicated that coated liposomes are more cytotoxic than plain liposomes and drug solution, indicating their potential for intracellular drug delivery. The cell-uptake study done on the lung cancer cell line indicated that calcium-phosphate-coated liposomes show higher cell uptake than uncoated liposomes.
载硫酸长春新碱脂质体旨在提高稳定性，减少药物在全身循环中的泄漏，并增加细胞内摄取。脂质体采用薄膜水化法制备，然后通过顺序添加法用磷酸钙进行涂层。对制备的制剂进行了粒径、ζ电位、药物包封效率、透射电子显微镜（TEM）形态学、体外药物释放曲线和体外细胞毒性研究。发现制剂变量（如药物：脂质比以及水合介质的性质和体积）会影响药物包封，涂层中氯化钙的浓度会影响粒径和涂层效率。粒径、ζ电位和 TEM 图像证实了脂质体已被有效地用磷酸钙进行了涂层。磷酸钙纳米壳表现出 pH 依赖性的药物释放，与 pH 7.4 相比，在 pH 4.5（肿瘤间质的 pH 值）下的释放明显较低。对肺癌细胞系进行的体外细胞毒性研究表明，包被的脂质体比普通脂质体和药物溶液具有更高的细胞毒性，表明它们具有用于细胞内药物递送的潜力。对肺癌细胞系进行的细胞摄取研究表明，磷酸钙涂层脂质体比未涂层脂质体具有更高的细胞摄取。
