The antioxidant quercetin (Q) is a bioactive compound that can inhibit colon cancer. However, its poor stability in the upper gastro-intestinal tract and low bioavailability compromised its benefits. In this study, a biopolymer-based colon-specific delivery system for Q was constructed by co-axial electrospinning. Quercetin-loaded chitosan nanoparticles (QCNP) were firstly prepared and characterized. Then, a Q-loaded electrospun fiber mat (Q-loaded EFM) containing prebiotics (galactooligosaccharide, GOS) was fabricated using sodium alginate as the shell layer and the abovementioned QCNP and prebiotics as the core layer. The DPPH assay showed that the antioxidant activity of Q was maintained in the obtained film. Owing to the addition of prebiotic GOS, the obtained fiber mat exhibited good prebiotic effects. In vitro release kinetics showed a sustained and targeted colon-specific release of Q from the Q-loaded EFM containing GOS, and the release rate of Q was enhanced by the presence of GOS. The obtained film also exhibited inhibition effects on Caco-2 cells in a dose- and time-dependent manner. Flow cytometry and fluorescence microscopy analysis indicated that the Q-loaded EFM containing GOS exerted its activity on colonic cancer cells by arresting the cell cycle in the G0/G1 phase and triggering apoptotic cell death. This study demonstrates the potential of the obtained film as an oral delivery system for encapsulation, protection, and release of Q at the colon for the oral therapy of colon disorders.

中文翻译：

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基于同轴静电纺丝的槲皮素结肠特异性递送系统，可增强癌症预防能力†

抗氧化剂槲皮素（Q）是一种可以抑制结肠癌的生物活性化合物。然而，其在上消化道中的差的稳定性和低的生物利用度损害了其益处。在这项研究中，通过同轴电纺丝构建了基于生物聚合物的Q结肠特异性递送系统。负载槲皮素的壳聚糖纳米颗粒（QCNP）的首次制备和表征。然后，以藻酸钠为壳层，以上述QCNP和益生元为核心层，制备了含有益生元（低聚半乳糖，GOS）的Q负载的电纺纤维毡（Q负载的EFM）。DPPH分析表明，在获得的膜中保持了Q的抗氧化活性。由于添加了益生元GOS，因此获得的纤维垫表现出良好的益生元效果。体外释放动力学表明，从含有QOS的载有QOS的EFM中，Q能够持续且有针对性地释放Q，并且由于GOS的存在，Q的释放速率得以提高。所获得的膜还以剂量和时间依赖性的方式对Caco-2细胞表现出抑制作用。流式细胞仪和荧光显微镜分析表明，含有QOS的Q负载EFM通过将细胞周期阻滞在G0 / G1期并触发凋亡性细胞死亡而发挥其对结肠癌细胞的活性。这项研究证明了所获得的薄膜作为口服递送系统的潜力，可用于结肠的口服治疗，结肠的Q的封装，保护和释放。