Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Research Institute of Eco-friendly Animal Science, Institute of Green-Bio Science and Technology, Seoul National University, Kangwon-Do 232-916, Republic of Korea.
Biomaterials. 2015 Aug;59:144-59. doi: 10.1016/j.biomaterials.2015.04.017. Epub 2015 May 15.
Orally delivered proteins or antigens are taken up by epithelial microfold cells (M cells) in Peyer's patches, especially abundant in the ileum of small intestine. However, several barriers including gastric pH, enzymatic degradation, rapid transit and lack of specificity of proteins towards M cells, has made the goal of oral delivery of proteins very challenging. To overcome the problems, we developed an ileum targeted protein delivery system using hydroxypropyl methylcellulose phthalate (HPMCP). Initially, we attuned pH-sensitive property of HPMCP for controlled dissolution at ileum pH (≥7.4) by thiolation. Thiolation also improved mucoadhesive property of HPMCP to prolong the particles transit time through the gastrointestinal tract. Typically, thiolated HPMCP (T-HPMCP) prevented protein release in acidic pH in stomach and duodenum but released the proteins at ileal pH in a controlled manner. To evaluate the effectiveness of an oral delivery vehicle, T-HPMCP was used to deliver an M cell targeting protein antigen to mice through oral route. The antigens were mostly delivered and located in Peyer's patches in the ileum demonstrating the higher uptake of antigens through M-cells. Importantly, oral delivery of the antigen with T-HPMCP not only induced strong antibody mediated immune responses but also generated memory T cells in the spleen as adaptive immunity indicating a direct evidence of an effective delivery system. Thus, this study represents the first demonstration of HPMCP for ileum-specific delivery of protein vaccine through oral route.
口服给予的蛋白质或抗原被派伊尔斑中的上皮微褶细胞 (M 细胞) 摄取，尤其是在小肠的回肠中丰富。然而，包括胃 pH 值、酶降解、快速转运和蛋白质对 M 细胞缺乏特异性等几个障碍，使得蛋白质的口服递送目标变得极具挑战性。为了克服这些问题，我们使用羟丙基甲基纤维素邻苯二甲酸酯 (HPMCP) 开发了一种回肠靶向蛋白质递送系统。最初，我们通过巯基化来调整 HPMCP 的 pH 敏感性，使其在回肠 pH(≥7.4) 时能够控制溶解。巯基化还提高了 HPMCP 的粘膜粘附性，从而延长了颗粒在胃肠道中的转运时间。通常，巯基化的 HPMCP (T-HPMCP) 在胃和十二指肠的酸性 pH 下阻止蛋白质释放，但在回肠 pH 下以受控方式释放蛋白质。为了评估口服递送载体的有效性，T-HPMCP 被用于通过口服途径向小鼠递送 M 细胞靶向蛋白质抗原。抗原主要在回肠的派尔斑中被递送至并定位于其中，这表明抗原通过 M 细胞的摄取增加。重要的是，T-HPMCP 口服递送抗原不仅诱导了强烈的抗体介导的免疫反应，而且还在脾脏中产生了记忆 T 细胞作为适应性免疫，这表明了一种有效的递送系统的直接证据。因此，这项研究代表了 HPMCP 首次通过口服途径用于回肠特异性蛋白质疫苗的递送。
