Department of Pharmaceutical Sciences and Pharmaceutics, Faculty of Pharmacy, Applied Science Private University, Amman 11931, Jordan; Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Eur J Pharm Biopharm. 2020 Oct;155:103-111. doi: 10.1016/j.ejpb.2020.08.012. Epub 2020 Aug 14.
The harsh conditions of the gastro-intestinal (GI) milieu pose a major barrier to the oral delivery of protein nanocages. Here we studied the stability of Nudaurelia capensis omega virus (NωV) virus-like particles (VLPs) in simulated GI fluids. NωV VLPs capsids and procapsids were transiently expressed in plants, the VLPs were incubated in various simulated GI fluids and their stability was determined by gel electrophoresis, density gradient ultracentrifugation and transmission electron microscopy (TEM). The results showed that the capsids were highly resistant to simulated gastric fluids at pH ≥ 3. Even under the harshest conditions, which consisted of a pepsin solution at pH 1.2, NωV capsids remained assembled as VLPs, though some digestion of the coat protein occurred. Moreover, 80.8% (±10.2%) stability was measured for NωV capsids upon 4 h incubation in simulated intestinal fluids. The high resistance of this protein cage to digestion and denaturation can be attributed to its distinctively compact structure. The more porous form of the VLPs, the procapsid, was less stable under all conditions. Our results suggest that NωV VLPs capsids are likely to endure transit through the GI tract, designating them as promising candidate protein nanocages for oral drug delivery.
胃肠道（GI）环境的苛刻条件对蛋白质纳米笼的口服递送构成了重大障碍。在这里，我们研究了 Nudaurelia capensis omega 病毒（NωV）病毒样颗粒（VLPs）在模拟 GI 液中的稳定性。NωV VLPs 衣壳和前衣壳在植物中瞬时表达，将 VLPs 孵育在各种模拟 GI 液中，并通过凝胶电泳、密度梯度超速离心和透射电子显微镜（TEM）测定其稳定性。结果表明，衣壳在 pH≥3 的模拟胃液中具有高度抗性。即使在最苛刻的条件下，即 pH 1.2 的胃蛋白酶溶液中，NωV 衣壳仍保持作为 VLPs 组装，尽管一些外壳蛋白发生了消化。此外，在模拟肠液中孵育 4 小时后，NωV 衣壳的稳定性为 80.8%（±10.2%）。这种蛋白质笼对消化和变性的高抗性可归因于其独特的紧凑结构。VLPs 的多孔形式，即前衣壳，在所有条件下都不太稳定。我们的结果表明，NωV VLPs 衣壳很可能在通过胃肠道的过程中存活下来，这使它们成为口服药物递送有前途的候选蛋白质纳米笼。
