Retinoblastoma (Rb) is the most common intraocular malignancy in children that accounts for approximately 4% of all pediatric malignancies. Since chemotherapy is a widely practiced treatment for Rb, there is a growing interest in developing new and effective drugs to overcome systemic and local side effects of chemotherapy to improve the quality of life and increase the chances of survival. This study sought to fabricate thiolated chitosan nanoparticles containing topotecan (TPH-TCs-NPs) with a view of enhancing drug loading and release control. This research was also designed to assess the ability of TPH-TCs-NPs to improve cell association, increase treatment efficacy in retinoblastoma cells and xenograft-rat-model of retinoblastoma, and overcome current topotecan hydrochloride (TPH) intravitreal administration challenges, including stability loss and poor cellular uptake. Modified ionic gelation method was optimized to fabricate TPH-TCs-NPs and TPH-TMC-NPs (N-trimethyl chitosan nanoparticles containing TPH). We characterized the NPs and quantified topotecan loading and release against a free TPH standard. The efficacy of TPH-NPs was quantified in human retinoblastoma cells (Y79) by XTT and flow cytometry measurement. In addition, Y79 cells were injected intravitreally in both eyes of immunodeficient wistar albino rats to create a xenograft-rat-model to compare the antitumor effectiveness of TPH-NPs and TPH by intravitreal administration. TPH-NPs complexation was confirmed by EDX, FTIR, and DSC techniques. TPH-TCs-NPs and TPH-TMC-NPs had high encapsulation efficiency (85.23 ± 2 and 73.34 ± 2% respectively). TPH-TCs-NPs showed a mean diameter, polidispersity index, and zeta potential of 25±2 nm, 0.21 ± 0.03 and +12 ± 2 mV, respectively. As a function of dose, TCs and TMC NPs were more efficacious than free topotecan (IC50s 53.17 and 85.88 nM, relative to 138.30 nM respectively, P = 0.012). Kruskal-Wallis test showed a statistically significant difference between the groups. Additionally, a significant difference between the tumor control and TPH-TCs-NPs treated group in xenograft-rat-model ( Range of P-value: 0.026 to 0.035) was shown by Bonferroni post hoc test. The current investigation demonstrated enhanced efficacy and association of TPH-TCs-NPs relative to free TPH in retinoblastoma cells and tumor in vitro and in vivo.

视网膜母细胞瘤 (Rb) 是儿童最常见的眼内恶性肿瘤，约占所有儿科恶性肿瘤的 4%。由于化学疗法是 Rb 的广泛实践的治疗方法，因此人们越来越有兴趣开发新的有效药物来克服化学疗法的全身和局部副作用，以提高生活质量并增加生存机会。本研究旨在制造含有拓扑替康的硫醇化壳聚糖纳米颗粒（TPH-TCs-NPs），以增强药物负载和释放控制。本研究还旨在评估 TPH-TCs-NPs 改善细胞结合、提高视网膜母细胞瘤细胞和视网膜母细胞瘤异种移植大鼠模型的治疗效果的能力，并克服当前的盐酸拓扑替康 (TPH) 玻璃体内给药挑战，包括稳定性丧失和细胞摄取不良。优化了改进的离子凝胶法以制备 TPH-TCs-NPs 和 TPH-TMC-NPs（含有 TPH 的 N-三甲基壳聚糖纳米颗粒）。我们根据游离的 TPH 标准对 NP 进行了表征，并量化了拓扑替康的加载和释放。通过 XTT 和流式细胞术测量，在人视网膜母细胞瘤细胞 (Y79) 中量化 TPH-NPs 的功效。此外，在免疫缺陷 wistar 白化大鼠的双眼玻璃体内注射 Y79 细胞以创建异种移植大鼠模型，以比较玻璃体内给药的 TPH-NPs 和 TPH 的抗肿瘤效果。通过 EDX、FTIR 和 DSC 技术证实了 TPH-NPs 复合。TPH-TCs-NPs 和 TPH-TMC-NPs 具有高封装效率（分别为 85.23 ± 2 和 73.34 ± 2%）。TPH-TCs-NPs 显示平均直径、多分散指数、和 zeta 电位分别为 25±2 nm、0.21 ± 0.03 和 +12 ± 2 mV。作为剂量的函数，TCs 和 TMC NPs 比游离拓扑替康更有效（IC50s 53.17 和 85.88 nM，分别相对于 138.30 nM，P = 0.012）。Kruskal-Wallis 检验显示各组之间存在统计学上的显着差异。此外，Bonferroni post hoc 检验显示异种移植大鼠模型中肿瘤对照和 TPH-TCs-NPs 治疗组之间的显着差异（P 值范围：0.026 至 0.035）。目前的研究表明，在体外和体内，TPH-TCs-NPs 相对于游离 TPH 在视网膜母细胞瘤细胞和肿瘤中的功效和关联性增强。分别相对于 138.30 nM，P = 0.012）。Kruskal-Wallis 检验显示各组之间存在统计学上的显着差异。此外，Bonferroni post hoc 检验显示异种移植大鼠模型中肿瘤对照和 TPH-TCs-NPs 治疗组之间的显着差异（P 值范围：0.026 至 0.035）。目前的研究表明，在体外和体内，TPH-TCs-NPs 相对于游离 TPH 在视网膜母细胞瘤细胞和肿瘤中的功效和关联性增强。分别相对于 138.30 nM，P = 0.012）。Kruskal-Wallis 检验显示各组之间存在统计学上的显着差异。此外，Bonferroni post hoc 检验显示异种移植大鼠模型中肿瘤对照和 TPH-TCs-NPs 治疗组之间的显着差异（P 值范围：0.026 至 0.035）。目前的研究表明，在体外和体内，TPH-TCs-NPs 相对于游离 TPH 在视网膜母细胞瘤细胞和肿瘤中的功效和关联性增强。