Yacobi Nazanin R, Demaio Lucas, Xie Jiansong, Hamm-Alvarez Sarah F, Borok Zea, Kim Kwang-Jin, Crandall Edward D
Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90033, USA.
Nanomedicine. 2008 Jun;4(2):139-45. doi: 10.1016/j.nano.2008.02.002. Epub 2008 Mar 28.
We investigated trafficking of polystyrene nanoparticles (PNP; 20 and 100 nm; carboxylate, sulfate, or aldehyde-sulfate modified [negatively charged] and amidine-modified [positively charged]) across rat alveolar epithelial cell monolayers (RAECM). Apical-to-basolateral fluxes of nanoparticles were estimated as functions of apical PNP concentration ([PNP]) and temperature. Uptake of nanoparticles into RAECM was determined using confocal microscopy. Fluxes increased as charge density became less negative/more positive, with positively charged PNPs trafficking 20-40 times faster than highly negatively charged PNP of comparable size. Trafficking rates decreased with increasing PNP diameter. PNP fluxes tended to level off at high apical [PNP]. Fluxes at 4 degrees C were significantly lower than those at 37 degrees C. Confocal microscopy revealed nanoparticles localized to cell cytoplasm, whereas cell junctions and nuclei appeared free of PNP. These data indicate that (1) trafficking of PNP across RAECM is strongly influenced by charge density, size, and temperature, (2) PNP translocate primarily transcellularly, and (3) PNP translocation requires cellular energy.
我们研究了聚苯乙烯纳米颗粒（PNP；20和100纳米；羧酸盐、硫酸盐或醛硫酸盐修饰[带负电荷]和脒修饰[带正电荷]）跨大鼠肺泡上皮细胞单层（RAECM）的转运情况。纳米颗粒从顶端到基底外侧的通量被评估为顶端PNP浓度（[PNP]）和温度的函数。使用共聚焦显微镜确定纳米颗粒被RAECM摄取的情况。随着电荷密度变得不那么负/更正，通量增加，带正电荷的PNP的转运速度比同等大小的高带负电荷的PNP快20 - 40倍。转运速率随着PNP直径的增加而降低。PNP通量在高顶端[PNP]时趋于平稳。4℃时的通量显著低于37℃时的通量。共聚焦显微镜显示纳米颗粒定位于细胞质中，而细胞连接和细胞核中未发现PNP。这些数据表明：（1）PNP跨RAECM的转运受到电荷密度、大小和温度的强烈影响；（2）PNP主要通过跨细胞转运；（3）PNP转运需要细胞能量。
