Faculty of Pharmacy, Universiti Sultan Zainal Abidin, Besut Campus, Besut 22200, Terengganu, Malaysia; Advanced Medical and Dental Institute, Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang, Malaysia.
Faculty of Pharmacy, Universiti Sultan Zainal Abidin, Besut Campus, Besut 22200, Terengganu, Malaysia.
Int J Biol Macromol. 2024 Nov;281(Pt 4):136549. doi: 10.1016/j.ijbiomac.2024.136549. Epub 2024 Oct 12.
Colon-targeted delivery offers several benefits for oral protein delivery, such as low proteolytic enzyme activity, a natural pH environment, and extended residence time, which improve the bioavailability of the encapsulated protein. Therefore, we hypothesize that developing a novel colonic nanocarrier system, featuring modified chitosan that is soluble at physiological pH and coated with a colon-degradable polymer, will provide an effective delivery system for oral insulin. This study aims to synthesize insulin-loaded pectin-trimethyl chitosan nanoparticles (Ins-P-TMC-NPs) as an oral insulin delivery system and to evaluate its efficacy both in vitro and in vivo. N-trimethyl chitosan (TMC), synthesized via a methylation method, was used to prepare insulin-TMC nanoparticles coated with pectin via the ionic gelation method. The nanoparticles were characterized for their physicochemical properties, cumulative release profile, and surface morphology. The in vitro biological cytotoxicity and cellular uptake of the nanoparticles were evaluated against HT-29 cells. The in vivo blood glucose-lowering effect and histological toxicity were assessed in diabetic male Sprague-Dawley rats. The results showed that Ins-P-TMC-NPs were spherical, with an average size of 379.40 ± 40.26 nm, a polydispersity index of 24.10 ± 1.03 %, a zeta potential of +17.20 ± 0.52 mV, and a loading efficiency of 83.21 ± 1.23 %. Compared to uncoated TMC nanoparticles, Ins-P-TMC-NPs reduced insulin loss in simulated gastrointestinal fluid by approximately 67.23 ± 0.97 % and provided controlled insulin release in simulated colonic fluid. In vitro bioactivity studies revealed that Ins-P-TMC-NPs were non-toxic, with cell viability of 91.12 ± 0.91 % after 24 h of treatment, and exhibited high cellular uptake in the HT-29 cell line with a fluorescence intensity of 37.80 ± 2.40 after 4 h of incubation. Furthermore, the in vivo study demonstrated a sustained reduction in blood glucose levels after oral administration of Ins-P-TMC-NPs, peaking after 8 h with a blood glucose reduction of 87 ± 1.03 %. Histological sections showed no signs of toxicity when compared to those of healthy rats. Overall, the developed colon-targeted oral insulin delivery system exhibits strong potential as a candidate for effective oral insulin administration.
结肠靶向递药为口服蛋白递药提供了多种益处，例如低蛋白水解酶活性、天然 pH 环境和延长的驻留时间，这些都提高了包裹蛋白的生物利用度。因此，我们假设开发一种新型结肠纳米载体系统，其特征为在生理 pH 下可溶的改性壳聚糖，并用结肠可降解聚合物进行涂层，将为口服胰岛素提供一种有效的递药系统。本研究旨在合成载胰岛素的果胶-三甲基壳聚糖纳米粒（Ins-P-TMC-NPs）作为口服胰岛素递药系统，并评估其在体外和体内的效果。通过甲基化方法合成 N-三甲基壳聚糖（TMC），并用离子凝胶法制备包被果胶的胰岛素-TMC 纳米粒。对纳米粒的理化性质、累积释放曲线和表面形态进行了表征。通过 HT-29 细胞评估了纳米粒的体外生物细胞毒性和细胞摄取。在糖尿病雄性 Sprague-Dawley 大鼠中评估了其体内降血糖作用和组织学毒性。结果表明，Ins-P-TMC-NPs 呈球形，平均粒径为 379.40±40.26nm，多分散指数为 24.10±1.03%，Zeta 电位为+17.20±0.52mV，载药效率为 83.21±1.23%。与未包被的 TMC 纳米粒相比，Ins-P-TMC-NPs 使模拟胃肠道液中的胰岛素损失减少约 67.23±0.97%，并在模拟结肠液中提供了控释胰岛素。体外生物活性研究表明，Ins-P-TMC-NPs 无毒性，处理 24 h 后细胞活力为 91.12±0.91%，孵育 4 h 后在 HT-29 细胞系中摄取率高，荧光强度为 37.80±2.40。此外，体内研究表明，口服给予 Ins-P-TMC-NPs 后血糖水平持续降低，8 h 时达到峰值，血糖降低 87±1.03%。与健康大鼠的组织切片相比，未见毒性迹象。总体而言，所开发的结肠靶向口服胰岛素递药系统具有作为有效口服胰岛素给药候选物的巨大潜力。
