Center for Chemistry and Biomedicine, Department of Pharmaceutical Technology, Institute of Pharmacy , University of Innsbruck , Innrain 80/82 , 6020 Innsbruck , Austria.
Department of Pharmacy , COMSATS University Islamabad , Abbottabad Campus , 22060 Abbottabad , Pakistan.
Mol Pharm. 2019 Jun 3;16(6):2817-2825. doi: 10.1021/acs.molpharmaceut.9b00355. Epub 2019 May 22.
The aim of the present study was to develop zeta potential-changing polyphosphate nanoparticles (pp-NPs) in order to overcome the diffusion barrier of the mucus gel layer and to provide an enhanced cellular uptake. pp-NPs were obtained by in situ gelation between cationic polyethylene imine and anionic polyphosphate. The resulting pp-NPs were characterized with regard to size and zeta potential. Phosphate release studies were carried out by incubation of pp-NPs with isolated as well as cell-associated intestinal alkaline phosphatase (IAP) and quantified by malachite green assay. Correspondingly, change in the zeta potential was measured, and pp-NPs were analyzed by scanning electron microscopy studies. Mucus permeation studies were performed with porcine intestinal mucus via the transwell insert method and rotating tube method. Furthermore, cell viability and cellular uptake were investigated on Caco-2 cells. The resulting pp-NPs displayed a mean size of 269.16 ± 1.12 nm and a zeta potential between -9 and -10 mV in the characterization studies. Within 4 h, a remarkable amount of phosphate was released from pp-NPs incubated with isolated IAP as well as cell-associated IAP and zeta potential raised up from -9.14 ± 0.45 to -1.75 ± 0.46 mV. Compared with dephosphorylated polyphosphate nanoparticles (de-pp-NPs), a significantly enhanced mucus permeation of pp-NPs was observed. Moreover, pp-NPs did not exhibit cytotoxicity. Cellular uptake increased 2.6-fold by conversion of pp-NPs to de-pp-NPs following enzymatic cleavage. Taking the comparatively simple preparation method and the high mucus-permeating properties of pp-NPs and high cellular uptake properties of de-pp-NPs into account, these nanocarriers might be promising novel tools for mucosal drug delivery.
本研究旨在开发具有变化 ζ 电位的多聚磷酸盐纳米粒（pp-NPs），以克服黏液凝胶层的扩散障碍，并提供增强的细胞摄取。pp-NPs 是通过阳离子聚乙烯亚胺和阴离子多聚磷酸盐之间的原位凝胶化获得的。对所得 pp-NPs 的粒径和 ζ 电位进行了表征。通过将 pp-NPs 与分离的和细胞相关的肠碱性磷酸酶（IAP）孵育进行磷酸盐释放研究，并通过孔雀绿测定法进行定量。相应地，测量了 ζ 电位的变化，并通过扫描电子显微镜研究分析了 pp-NPs。通过跨膜插入法和旋转管法对猪肠黏液进行了黏液渗透研究。此外，还在 Caco-2 细胞上研究了细胞活力和细胞摄取。在表征研究中，所得 pp-NPs 的平均粒径为 269.16 ± 1.12nm，ζ 电位在-9 到-10mV 之间。在 4 小时内，与分离的 IAP 以及细胞相关的 IAP 孵育的 pp-NPs 释放出大量的磷酸盐，ζ 电位从-9.14 ± 0.45 升高至-1.75 ± 0.46mV。与去磷酸化多聚磷酸盐纳米粒（de-pp-NPs）相比，pp-NPs 的黏液渗透性明显增强。此外，pp-NPs 没有表现出细胞毒性。通过酶切将 pp-NPs 转化为 de-pp-NPs，细胞摄取增加了 2.6 倍。考虑到 pp-NPs 相对简单的制备方法、高黏液渗透性和 de-pp-NPs 的高细胞摄取特性，这些纳米载体可能是黏膜药物递送的有前途的新型工具。
