Colorectal cancer is the third most frequent type of cancer and the second leading cause of cancer-related deaths worldwide. The majority of cases are diagnosed at a later stage, leading to the need for more aggressive treatments such as chemotherapy. 5-Fluorouracil (5-FU), known for its high cytotoxic properties has emerged as a chemotherapeutic agent. However, it presents several drawbacks such as lack of specificity and short half-life. To reduce these drawbacks, several strategies have been designed namely chemical modification or association to drug delivery systems. Current research was focused on the design, physicochemical characterization and evaluation of a lipid-based system loaded with 5-FU. Furthermore, aiming to maximize preferential targeting and release at tumour sites, a hybrid lipid-based system, combining both therapeutic and magnetic properties was developed and validated. For this purpose, liposomes co-loaded with 5-FU and iron oxide (II, III) nanoparticles were accomplished. The characterization of the developed nanoformulation was performed in terms of incorporation parameters, mean size and surface charge. studies assessed in a murine colon cancer cell line confirmed that 5-FU antiproliferative activity was preserved after incorporation in liposomes. In same model, iron oxide (II, III) nanoparticles did not exhibit cytotoxic properties. Additionally, the presence of these nanoparticles was shown to confer magnetic properties to the liposomes, allowing them to respond to external magnetic fields. Overall, a lipid nanosystem loading a chemotherapeutic agent displaying magnetic characteristics was successfully designed and physicochemically characterized, for further applications.

中文翻译：

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一种结合细胞毒性和磁性的替代混合脂质纳米系统作为增强 5-氟尿嘧啶抗肿瘤作用的工具

结直肠癌是全球第三常见的癌症类型，也是全球癌症相关死亡的第二大原因。大多数病例在晚期才被诊断出来，导致需要更积极的治疗，例如化疗。 5-氟尿嘧啶 (5-FU) 以其高细胞毒性特性而闻名，已成为一种化疗药物。然而，它存在一些缺点，例如缺乏特异性和半衰期短。为了减少这些缺点，已经设计了几种策略，即化学修饰或与药物递送系统结合。目前的研究重点是装载 5-FU 的脂质系统的设计、理化表征和评估。此外，为了最大限度地在肿瘤部位优先靶向和释放，开发并验证了一种结合了治疗和磁性特性的混合脂质系统。为此，我们制备了共负载 5-FU 和氧化铁 (II, III) 纳米颗粒的脂质体。根据掺入参数、平均尺寸和表面电荷对所开发的纳米制剂进行表征。对小鼠结肠癌细胞系进行评估的研究证实，5-FU 掺入脂质体后仍保留其抗增殖活性。在同一模型中，氧化铁 (II, III) 纳米颗粒没有表现出细胞毒性。此外，这些纳米颗粒的存在被证明赋予脂质体磁性，使它们能够对外部磁场做出反应。总体而言，成功设计了负载具有磁性特性的化疗剂的脂质纳米系统并进行了物理化学表征，以供进一步应用。