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)2 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 [64Cu]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.

中文翻译：

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使用温度敏感脂质体制剂的水溶性抗癌铜离子载体系统的开发和体内应用。

制备了含铜和铜离子载体新cuproine的脂质体，并对其体外和体内抗癌活性进行了表征。在铜（II）离子存在下，以不同摩尔比的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）制备热敏性聚乙二醇化脂质体。以70:30 DPPC与HSPC重量比获得最佳的温度依赖性药物释放。通过在脂质体内部使用pH 4.5的非缓冲溶液和在脂质体外部使用pH 7.8的100 mM HEPES缓冲液，通过pH梯度将Neocuproine（以0.2 mol至1 mol的磷脂施用）封装。铜离子过量存在，产生0.5 mM的铜-（新古铜）2络合物和0.5 mM的游离铜。在短期的体外实验中，预热至45°C会增加热敏脂质体的毒性，而在72 h时，所有研究的脂质体均表现出与铜（II）-新古铜复合物（1：1比例）相似的体外毒性。 ）。无论温和的高温治疗如何，都发现热敏脂质体在植入C26癌细胞的BALB / c小鼠中可更有效地减少肿瘤的生长。在用[64Cu] Cu-新皮氨酸脂质体治疗后，通过PET / CT成像验证了铜的摄取。综上所述，我们的结果证明了靶向铜纳米毒素的可行性，该铜纳米毒素被封装在含有过量铜的热敏脂质体中。1个比率）。无论温和的高温治疗如何，都发现热敏脂质体在植入C26癌细胞的BALB / c小鼠中可更有效地减少肿瘤的生长。在用[64Cu] Cu-新皮氨酸脂质体治疗后，通过PET / CT成像验证了铜的摄取。综上所述，我们的结果证明了靶向铜纳米毒素的可行性，该铜纳米毒素被封装在含有过量铜的热敏脂质体中。1个比率）。无论温和的高温治疗如何，都发现热敏脂质体在植入C26癌细胞的BALB / c小鼠中可更有效地减少肿瘤的生长。在用[64Cu] Cu-新皮氨酸脂质体治疗后，通过PET / CT成像验证了铜的摄取。综上所述，我们的结果证明了靶向铜纳米毒素的可行性，该铜纳米毒素被封装在含有过量铜的热敏脂质体中。