Faculty of Pharmacy, Van Lang University, Ho Chi Minh City 70000, Vietnam; School of Pharmacy, University of Otago, Dunedin 9016, New Zealand.
Department of Pathology, University of Otago, Dunedin 9016, New Zealand.
Int J Pharm. 2024 Oct 25;664:124621. doi: 10.1016/j.ijpharm.2024.124621. Epub 2024 Aug 28.
Conjugation of a therapeutic agent to a polymer for enhanced delivery into target cells followed by its intracellular triggered release has proved to be an effective drug delivery approach. This approach is applied to the delivery of the immune-stimulatory unmethylated cytosine-phosphate-guanine (CpG) oligonucleotide for an anti-tumour immune response after intratumoral administration. On average four CpG-1668 molecules were covalently linked to a 40-kDa amino-functionalised dextran polymer via either a non-reversible (CpG-dextran) or an intracellular redox-responsive disulfide linkage (CpG-SS-dextran). Dynamic light scattering analysis showed that both conjugates had a similar particle size and surface charge of 17 nm and -10 mV, respectively. Agarose gel electrophoresis analysis showed that CpG-SS-dextran was stable in the extracellular low glutathione (GSH) concentration range (i.e. 10-20 μM) and was cleaved at the higher intracellular GSH concentration (5 mM), while CpG-dextran was stable in both GSH concentrations. Uptake and activation assays on bone-marrow-derived dendritic cells showed no significant difference between free CpG, CpG-dextran and CpG-SS-dextran. In a mouse subcutaneous colorectal tumour model the CpG-SS-dextran showed a statistically significantly greater inhibition of tumour growth (p < 0.03) and prolonged survival (p < 0.001) compared to CpG-dextran or free CpG. These results demonstrate that the redox-triggered intracellular release of CpG from a dextran polymer carrier has promise for intratumoral therapeutic vaccination against cancer.
将治疗剂与聚合物缀合以增强递送至靶细胞，然后在细胞内触发释放，已被证明是一种有效的药物递送方法。该方法应用于肿瘤内给药后递送免疫刺激性非甲基化胞嘧啶-磷酸-鸟嘌呤（CpG）寡核苷酸以产生抗肿瘤免疫反应。平均有四个 CpG-1668 分子通过非可逆（CpG-葡聚糖）或细胞内氧化还原响应性二硫键连接（CpG-SS-葡聚糖）共价连接到 40-kDa 氨基官能化葡聚糖聚合物上。动态光散射分析表明，两种缀合物的粒径和表面电荷相似，分别为 17nm 和-10mV。琼脂糖凝胶电泳分析表明，CpG-SS-葡聚糖在细胞外低谷胱甘肽（GSH）浓度范围内（即 10-20μM）稳定，并且在较高的细胞内 GSH 浓度（5mM）下被切割，而 CpG-葡聚糖在两种 GSH 浓度下均稳定。骨髓来源的树突状细胞的摄取和激活测定表明，游离 CpG、CpG-葡聚糖和 CpG-SS-葡聚糖之间没有明显差异。在小鼠皮下结直肠肿瘤模型中，CpG-SS-葡聚糖显示出统计学上显著更大的肿瘤生长抑制（p<0.03）和生存延长（p<0.001），与 CpG-葡聚糖或游离 CpG 相比。这些结果表明，从葡聚糖聚合物载体中通过氧化还原触发细胞内释放 CpG 具有用于肿瘤内治疗性疫苗接种以对抗癌症的潜力。
