Gaál Anikó, Garay Tamás M, Horváth Ildikó, Máthé Domokos, Szöllősi Dávid, Veres Dániel S, Mbuotidem Jeremiah, Kovács Tibor, Tóvári József, Bergmann Ralf, Streli Christina, Szakács Gergely, Mihály Judith, Varga Zoltán, Szoboszlai Norbert
Biological Nanochemistry Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary.
Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, H-1083 Budapest, Práter utca 50/a, Hungary.
Pharmaceutics. 2020 May 20;12(5):466. doi: 10.3390/pharmaceutics12050466.
Liposomes containing copper and the copper ionophore neocuproine were prepared and characterized for in vitro and in vivo anticancer activity. Thermosensitive PEGylated liposomes were prepared with different molar ratios of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and hydrogenated soybean phosphatidylcholine (HSPC) in the presence of copper(II) ions. Optimal, temperature dependent drug release was obtained at 70:30 DPPC to HSPC weight ratio. Neocuproine (applied at 0.2 mol to 1 mol phospholipid) was encapsulated through a pH gradient while using unbuffered solution at pH 4.5 inside the liposomes, and 100 mM HEPES buffer pH 7.8 outside the liposomes. Copper ions were present in excess, yielding 0.5 mM copper-(neocuproine) complex and 0.5 mM free copper. Pre-heating to 45 °C increased the toxicity of the heat-sensitive liposomes in short-term in vitro experiments, whereas at 72 h all investigated liposomes exhibited similar in vitro toxicity to the copper(II)-neocuproine complex (1:1 ratio). Thermosensitive liposomes were found to be more effective in reducing tumor growth in BALB/c mice engrafted with C26 cancer cells, regardless of the mild hyperthermic treatment. Copper uptake of the tumor was verified by PET/CT imaging following treatment with [Cu]Cu-neocuproine liposomes. Taken together, our results demonstrate the feasibility of targeting a copper nanotoxin that was encapsulated in thermosensitive liposomes containing an excess of copper.
制备了含有铜和铜离子载体新亚铜试剂的脂质体，并对其体外和体内抗癌活性进行了表征。在铜（II）离子存在的情况下，用不同摩尔比的1,2-二棕榈酰-sn-甘油-3-磷脂酰胆碱（DPPC）和氢化大豆磷脂酰胆碱（HSPC）制备了热敏聚乙二醇化脂质体。在DPPC与HSPC重量比为70:30时获得了最佳的、温度依赖性药物释放。新亚铜试剂（以0.2摩尔对1摩尔磷脂的比例应用）通过pH梯度进行包封，同时在脂质体内部使用pH 4.5的无缓冲溶液，在脂质体外部使用100 mM pH 7.8的HEPES缓冲液。铜离子过量存在，产生0.5 mM铜-（新亚铜试剂）络合物和0.5 mM游离铜。在短期体外实验中，预热至45°C可增加热敏脂质体的毒性，而在72小时时，所有研究的脂质体对铜（II）-新亚铜试剂络合物（1:1比例）表现出相似的体外毒性。发现热敏脂质体在减少接种C26癌细胞的BALB/c小鼠肿瘤生长方面更有效，无论是否进行轻度热疗。在用[Cu]Cu-新亚铜试剂脂质体治疗后，通过PET/CT成像验证了肿瘤对铜的摄取。综上所述，我们的结果证明了靶向封装在含有过量铜的热敏脂质体中的铜纳米毒素的可行性。
