Behrens Isabel, Pena Ana Isabel Vila, Alonso Maria José, Kissel Thomas
Department of Pharmaceutics and Biopharmaceutics, University of Marburg, Marburg/Lahn, Germany.
Pharm Res. 2002 Aug;19(8):1185-93. doi: 10.1023/a:1019854327540.
The interaction of nanoparticles (NP), consisting of hydrophobic polystyrene, bioadhesive chitosan, and stealth PLA-PEG with two human intestinal cell lines, the enterocyte-like Caco-2 and mucus-secreting MTX-E12, was investigated and compared to the in vivo NP uptake in rats.
The extent and mechanism of cellular association of different NP with Caco-2 and MTX-E12 was investigated using confocal laser scanning microscopy (CLSM) and a cellular association assay. In vitro results were compared to gastrointestinal distribution of chitosan NP in rats after intra-duodenal injection.
Cellular association of NP with Caco-2 cell monolayers showed the following rank order: polystyrene > chitosan >> PLA-PEG. Mucus (MTX-E12) significantly decreased the association of hydrophobic polystyrene NP. While no mucus binding was observed for PLA-PEG, association of chitosan NP with mucus strongly increased. Intra-duodenal administration of chitosan NP in rats confirmed these in vitro results, demonstrating that NP could be detected in both epithelial cells and Peyer's patches. Chitosan NP internalization was saturable, as well as energy- and temperature-dependent. It could be inhibited by an excess of protamine and by removal of anionic sites of the apical membrane. By contrast, polystyrene NP uptake was found to be largely independent of these factors, except for a temperature-dependency.
In contrast to Caco-2 cells, the presence of mucus presented a major barrier for the uptake of hydrophobic polystyrene NP and showed an even more profound effect upon the uptake of chitosan NP. A correlation between the uptake in cell culture models and in vivo rat epithelial cells was confirmed for chitosan NP. Moreover, chitosan NP seemed to be taken up and transported by adsorptive transcytosis, while polystyrene NP uptake was probably mediated by non-adsorptive transcytosis.
研究了由疏水性聚苯乙烯、生物粘附性壳聚糖和隐形聚乳酸-聚乙二醇（PLA-PEG）组成的纳米颗粒（NP）与两种人肠道细胞系，即肠上皮样Caco-2细胞和分泌黏液的MTX-E12细胞之间的相互作用，并与大鼠体内NP摄取情况进行比较。
使用共聚焦激光扫描显微镜（CLSM）和细胞结合试验研究了不同NP与Caco-2细胞和MTX-E12细胞的细胞结合程度及机制。将体外结果与大鼠十二指肠内注射壳聚糖NP后的胃肠道分布情况进行比较。
NP与Caco-2细胞单层的细胞结合呈现以下顺序：聚苯乙烯＞壳聚糖＞＞PLA-PEG。黏液（MTX-E12）显著降低了疏水性聚苯乙烯NP的结合。虽然未观察到PLA-PEG与黏液结合，但壳聚糖NP与黏液的结合显著增加。大鼠十二指肠内给予壳聚糖NP证实了这些体外结果，表明在大鼠上皮细胞和派尔集合淋巴结中均可检测到NP。壳聚糖NP的内化是可饱和的，且依赖能量和温度。它可被过量的鱼精蛋白抑制，并可通过去除顶端膜的阴离子位点来抑制。相比之下，发现聚苯乙烯NP的摄取在很大程度上不受这些因素影响，除了对温度有依赖性。
与Caco-2细胞不同，黏液的存在对疏水性聚苯乙烯NP的摄取构成了主要障碍，对壳聚糖NP的摄取影响更为显著。壳聚糖NP在细胞培养模型中的摄取与大鼠体内上皮细胞摄取之间的相关性得到了证实。此外，壳聚糖NP似乎通过吸附转胞吞作用被摄取和转运，而聚苯乙烯NP的摄取可能由非吸附转胞吞作用介导。
