Department of Biomedical Sciences, University of Cagliari, Italy; INN, National Institute of Neuroscience, University of Cagliari, Italy.
Department of Life and Environmental Sciences, University of Cagliari, Italy; CNBS, University of Cagliari, Italy.
Int J Pharm. 2015 Feb 1;479(1):129-37. doi: 10.1016/j.ijpharm.2014.12.057. Epub 2015 Jan 2.
The aim of this work was to evaluate the capability of lactoferrin- and antitransferrin-modified long circulating liposomes to deliver the hydrophilic peptide senktide, a selective NK3 receptor agonist unable to cross the blood brain barrier, to central nervous system by using an indirect method based on in vivo microdialysis studies to estimate the responsiveness of nucleus accumbens shell dopamine to senktide. To this purpose, senktide was encapsulated in different targeted and not-targeted stealth liposomes prepared using film hydration method. Formulations were characterized in terms of morphology, size distribution, zeta potential, encapsulation efficiency, and antibody presence on the liposome surface. In vivo microdialysis studies were performed injecting intravenously the senktide-loaded liposomes and comparing obtained dopamine levels with those found with the free senktide given intracerebroventricularly. Results showed that all vesicles were spherical, small in size (around 120 nm), homogeneously dispersed, and slightly negatively charged. TEM analysis, using an anti IgG secondary antibody with 10nm gold nanoparticles at its distal end, demonstrated the successful linkage of the antibody on the liposomal surface. Intravenously administered in rats, senktide-loaded targeted stealth liposomes elicited a significant increase of dialysate dopamine in the nucleus accumbens shell, which was comparable to that of the free senktide given intracerebroventricularly when antitransferrin-targeted liposomes were tested. On the contrary, control stealth liposomes did not affect dopamine levels. Senktide brain levels were higher using the antitransferrin-targeted liposomes in comparison with the lactoferrin ones, while the opposite was obtained in the liver tissue where the highest senktide accumulation was always found.
这项工作的目的是评估乳铁蛋白和抗转铁蛋白修饰的长循环脂质体将亲水性肽 senktide（一种不能穿过血脑屏障的选择性 NK3 受体激动剂）递送至中枢神经系统的能力，使用基于体内微透析研究的间接方法来估计核壳accumbens 多巴胺对 senktide 的反应性。为此，将 senktide 包裹在使用薄膜水化法制备的不同靶向和非靶向隐形脂质体中。制剂的形态、粒径分布、Zeta 电位、包封效率和脂质体表面抗体的存在进行了表征。进行体内微透析研究，静脉内注射负载 senktide 的脂质体，并将获得的多巴胺水平与脑室内给予游离 senktide 时的水平进行比较。结果表明，所有囊泡均为球形，粒径小（约 120nm），均匀分散，略带负电荷。TEM 分析使用末端带有 10nm 金纳米颗粒的抗 IgG 二级抗体，证明了抗体成功连接到脂质体表面。在大鼠体内静脉给药后，负载 senktide 的靶向隐形脂质体在壳核 accumbens 中引发了显著增加的透析液多巴胺，当测试抗转铁蛋白靶向脂质体时，与脑室内给予的游离 senktide 相当。相反，对照隐形脂质体不会影响多巴胺水平。与乳铁蛋白靶向脂质体相比，使用抗转铁蛋白靶向脂质体时，senktide 的脑内水平更高，而在肝脏组织中则相反，在肝脏组织中始终发现最高的 senktide 积累。
