Technical University of Denmark, Department of Micro- and Nanotechnology, Frederiksborgvej 399, 4000 Roskilde, Denmark.
J Biomed Nanotechnol. 2009 Dec;5(6):676-82. doi: 10.1166/jbn.2009.1084.
Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green as pH sensitive dyes, which gave a dynamic pH measurement range from 4.1-7.5. Thus, the sensors cover the pH range of almost all intracellular compartments in mammalian cells. Both neutral and cationic polyacrylamide particles were synthesized where (3-acrylamidopropyl) trimethylammonium chloride was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells.
聚合物纳米粒子传感器已被构建用于研究哺乳动物细胞内吞途径中的 pH 值。荧光比率测量的 pH 传感器是通过反相微乳液聚合制备的，其中罗丹明作为参比荧光团，荧光素和 Oregon Green 作为 pH 敏感染料，其动态 pH 值测量范围为 4.1-7.5。因此，这些传感器涵盖了哺乳动物细胞中几乎所有细胞内区室的 pH 值范围。同时合成了中性和阳离子聚丙烯酰胺颗粒，其中（3-丙烯酰胺丙基）三甲基氯化铵用于在阳离子颗粒中引入净正电荷。研究发现，带正电荷的粒子传感器可被 HepG2 癌细胞自发内吞。这些新的 pH 纳米传感器是在活细胞内吞途径中实时定量 pH 值的潜在工具。
