This study presents the development of melatonin-coated lactoferrin-chitosan nanoparticles (ETP-CS-LF-MLT-NPs) using ionic gelation and carbodiimide coupling for colorectal cancer treatment. The nanoparticles were characterized by an average size of 208.7 ± 1.25 nm, a zeta potential of 30.77 ± 1.21 mV, and 82.45 % drug encapsulation efficiency. In vitro drug release studies showed sustained, pH-responsive release, with 98.68 ± 4.12 % released at pH 5.5 over 24 h. The nanoparticles exhibited significant cytotoxicity in HCT116 cells (IC50 = 15.32 μg/mL), inducing ROS generation, apoptosis, and G2/M cell cycle arrest, with notable downregulation of BCL2 gene expression. Enhanced cellular uptake due to lactoferrin targeting improved therapeutic efficacy. In In vivo studies, the nanoparticles demonstrated significant tumor reduction and selective colon accumulation in a DMH-induced colorectal cancer rat model, along with improved pharmacokinetics, showing extended plasma circulation and bioavailability compared to free etoposide. Biocompatibility assays, including hemolysis (<1 %), platelet aggregation, and HET-CAM tests, confirmed the safety profiling of the prepared nanoparticles. The nanoparticles also inhibited Proteus mirabilis (ZOI = 1.9 cm) and exhibited promising effects on the gut microbiome of treated animals. Altogether, ETP-CS-LF-MLT-NPs hold great potential for targeted colorectal cancer therapy, improving drug delivery, tumor targeting, bioavailability, and reducing systemic toxicity.

中文翻译：

---

通过碳二亚胺偶联制造含褪黑素的乳铁蛋白-壳聚糖-依托泊苷纳米颗粒：结肠癌的体外和体内评估


本研究介绍了使用离子凝胶和碳二亚胺偶联治疗褪黑激素包被的乳铁蛋白-壳聚糖纳米颗粒 （ETP-CS-LF-MLT-NPs） 的开发，用于治疗结直肠癌。纳米颗粒的平均尺寸为 208.7 ± 1.25 nm，zeta 电位为 30.77 ± 1.21 mV，药物包封效率为 82.45%。体外药物释放研究表明，在 pH 值为 5.5 的情况下，在 24 小时内释放 98.68 ± 4.12%。纳米颗粒在 HCT116 细胞中表现出显着的细胞毒性 （IC50 = 15.32 μg/mL），诱导 ROS 生成、细胞凋亡和 G2/M 细胞周期停滞，BCL2 基因表达显着下调。由于乳铁蛋白靶向而增强细胞摄取，提高了治疗效果。在体内研究中，纳米颗粒在 DMH 诱导的结直肠癌大鼠模型中表现出显着的肿瘤减少和选择性结肠积累，同时药代动力学得到改善，与游离依托泊苷相比，显示出延长的血浆循环和生物利用度。生物相容性测定，包括溶血 （<1 %）、血小板聚集和 HET-CAM 测试，证实了制备的纳米颗粒的安全性。纳米颗粒还抑制了奇异变形杆菌 （ZOI = 1.9 cm），并对治疗动物的肠道微生物组表现出有希望的效果。总之，ETP-CS-LF-MLT-NPs 在靶向结直肠癌治疗、改善药物输送、肿瘤靶向、生物利用度和降低全身毒性方面具有巨大潜力。