Oh Yeonsu, Wi Rinbok, Choi Yeon Beom, Kim Do Hyun, Chae Chanhee
Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 599 Gwanak-Ro, Gwanak-Gu, Seoul 151-921, Republic of Korea.
J Nanosci Nanotechnol. 2012 Jul;12(7):6131-8. doi: 10.1166/jnn.2012.6370.
Liposomes are small lipid vesicles that mimic biological membranes and have been spotlighted in the clinical field due to their ability to enclose a biologically active substance of any structure and to release it into the host's body. This study compares the physicochemical properties and biological activity of nano-liposomes with different compositions to determine the most effective formulation for further in vivo application. Nano-scale liposomes composed of different ratios of 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE), dihexadecyl phosphate (DCP), and cholesterol (Chol): DMPE, DMPE/DCP, DMPE/Chol, and DMPE/DCP/Chol were produced. The thermal phase transition was assessed via differential scanning calorimetry (DSC); the particle size, via dynamic light scattering (DLS); the colloidal stability, via the zeta potential; the direct morphological characterization, via transmission electron microscopy (TEM); and the protein encapsulation efficiency. The bioavailability was also investigated with respect to the immunological responses via porcine interferon gamma (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay in peripheral blood mononuclear cells (PBMC) of immunocompetent pigs. All the liposomes can be expected to be stable in an in vivo physiological temperature, and the liposomes that were prepared from DMPE/DCP showed the best efficiency in the in vitro model that mimicked the release of a bioactive substance in vivo. In the result of DLS and the zeta potential for the investigation of the colloidal stability in the system, DMPE/DCP/Chol appeared better than the other formulations. The porcine IFN-gamma ELISPOT assay results postulated that DMPE/DCP most potently induced the IFN-gamma secretion by PBMC, followed by DMPE/DCP/Chol and DMPE alone, in that order.
脂质体是模仿生物膜的小型脂质囊泡,由于其能够包裹任何结构的生物活性物质并将其释放到宿主体内,因而在临床领域备受关注。本研究比较了不同组成的纳米脂质体的物理化学性质和生物活性,以确定最有效的制剂以便进一步用于体内应用。制备了由不同比例的1,2-二肉豆蔻酰-sn-甘油-3-磷酸乙醇胺(DMPE)、磷酸二己酯(DCP)和胆固醇(Chol)组成的纳米级脂质体:DMPE、DMPE/DCP、DMPE/Chol和DMPE/DCP/Chol。通过差示扫描量热法(DSC)评估热相变;通过动态光散射(DLS)评估粒径;通过zeta电位评估胶体稳定性;通过透射电子显微镜(TEM)进行直接形态表征;并评估蛋白质包封效率。还通过猪干扰素γ(IFN-γ)酶联免疫斑点(ELISPOT)测定法在具有免疫活性的猪的外周血单核细胞(PBMC)中研究了关于免疫反应的生物利用度。预计所有脂质体在体内生理温度下都是稳定的,并且由DMPE/DCP制备的脂质体在模拟生物活性物质体内释放的体外模型中表现出最佳效率。在用于研究系统中胶体稳定性的DLS和zeta电位结果中,DMPE/DCP/Chol似乎比其他制剂更好。猪IFN-γ ELISPOT测定结果表明,DMPE/DCP最有效地诱导PBMC分泌IFN-γ,其次是DMPE/DCP/Chol和单独的DMPE,顺序依次如此。