Research of the relationship of intracellular acidification and apoptosis in Hela cells based on pH nanosensors

Abstract

In this paper, the relationship of intracellular acidification and apoptosis in Hela cells induced by vincristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group, employing fluorescein isothiocyanate (FITC) doped as the pH-sensitive dye and Tris(2,2'-bipyidyl) dichlororuthenium(II) hexahydrate (RuBpy) doped as reference dye. The pH change of the Hela cells induced by vincristine sulfate has been monitored in vivo, in situ and real time by use of the ratiometric pH nanosensors. The experimental results show that the pH of the apoptotic Hela cells induced by vincristine sulfate has been acidified from 7.11 to 6.51, and the percentage of intracellular acidification is correlated with the induced concentration and incubation time of the vincristine sulfate. The further study of the percentage of intracellular acidification and the percentage of apoptosis of Hela cells at the same time reveals that apoptosis of Hela cells induced by vincristine sulfate is preceded by intracellular acidification. These results would provide theoretical foundation for the therapy of cancer through interfering the pH of cells by use of vincristine sulfate or other anti-cancer drugs. ratiometric pH nanosensors, vincristine sulfate, Hela cells, intracellular acidification, apoptosis of cellsApoptosis is a programmed cell death process with great active roles in biology, which regulates and controls the physiological process together with mitosis such as development of embryo, differentiation of tissue, immunity and decrepitude of individual and so on [1] . The occurrence of apoptosis involves not only the related genes including survivable genes (e.g. Bcl-2 and Bcl-x) and deadly genes (e.g. C-myc and P53), but also the accommodation of intracellular signal systems such as the concentration of dissociative calcium ion, endogenous endonuclease, intracellular pH and so on [2,3] . Therefore, illustration of the influencing factors and relationships between intracellular signals transmission during the cell apoptosis is all of great importance to understand the evolution of life, the occurrence of disease and the directed disease therapy of drugs. Up to now, many research results [4][5][6] have showed that the cell apoptosis was correlated with the change of intracellular pH. The intracellular acidification has become a notable feature

Functionalized Silica Nanoparticles: A Platform for Fluorescence Imaging at the Cell and Small Animal Levels

“…Both lysosomal pH changes in murine macrophages stimulated by chloroquine and the intracellular acidification in apoptotic cancer cells were monitored in real time and with high pH sensitivity. Furthermore, the relationship of intracellular acidification and apoptosis in HeLa cells induced by vincristine sulfate was studied with this ratiometric pH nanosensors, which revealed that apoptosis was preceded by intracellular acidification . These results would provide theoretical foundation for the therapy of cancer through the interference of cells’ pH by use of vincristine sulfate or other anticancer drugs.…”

“…Furthermore, the relationship of intracellular acidification and apoptosis in HeLa cells induced by vincristine sulfate was studied with this ratiometric pH nanosensors, which revealed that apoptosis was preceded by intracellular acidification. 45 These results would provide theoretical foundation for the therapy Since functionalized SiNPs could enter into cells and locate in some certain organelles, they could also be utilized by nanoparticle-based controlled release systems for intracellular drug delivery and therapy studies. In order to increase the drug load amount, mesoporous SiNPs were selected to fabricate stimuli-responsive intracellular controlled release systems.…”

Protein analysis based on molecular beacon probes and biofunctionalized nanoparticles

“…We have developed uniform biofunctionalized core/shell NPs, composed of a functionalized fluorescent or magnetic core, a modifiable coating shell, and the biomolecules modified on the surface of the nanoparticles, as shown in Figure 8. The three parts all prominently contribute to their application of biomedicine, such as cell staining [92][93][94][95][96][97][98][99][100][101][102], bacteria detection [103,104], nanosensing [105,106], biomolecule detection and separation [107][108][109][110][111], gene and drug delivery [112][113][114][115][116], and biotechnological application in DNA protection [117]. Here, a few applications for protein detection and separation using biofunctionalized nanoparticles are discussed.…”