Page 9 - Flipbook-Advances_in_Science_v1c_Neat
P. 9
STIM Alpha particle- Optical fluorescence induced fluorescence Magnification: 100X 10 µm 10 µm Figure 2: The CIBA cell imaging beamline. outside the vacuum. Whole Cell Imaging 3 µm 3 µm The main applicaton for our high- (B) (C) resoluton imaging system is whole (A) cell imaging [1]. Since MeV ions are Figure 3: 100 nm fuorescent nanodiamonds in HeLa Cells. (A) Scanning able to penetrate a whole cell, no Transmission Ion Microscopy image showing the variaton in density. (B) Alpha additonal sectoning or thinning of partcle induced fuorescence image of the nanodiamonds in the cell. (C) The the cell sample is required for analysis. optcal wide-feld fuorescence image of the same region. The only sample preparaton that is required are the typical protocols used nanodiamonds by the HeLa cells and fuorescence image for comparison. for performing analysis under vacuum determine whether they are toxic to This image was taken with a wide-feld such as drying, fxing, etc. Afer sample the cell. In additon, we wanted to see fuorescence microscope so it does not preparaton, the cell structure remains where the nanopartcles went and have the resoluton required to see the intact. whether they are able to penetrate individual fuorescent nanodiamonds into the nucleus. Nanodiamonds are in the cell. One of the ongoing projects for cell of partcular interest because they imaging is looking at the uptake of have a bright fuorescence emission Conclusion various types of nanopartcles by under ion beam excitaton. They are cells [2]. The analysis that we can also stable, do not bleach very easily The whole cell imaging beam-line perform quanttatvely is important and are biocompatble. Figure 3A that we have developed in CIBA is a for applicatons such as drug delivery shows the STIM image of two HeLa unique instrument that can be used to [3]. Depending on the nanopartcles cells. The nucleus is easily observable perform quanttatve imaging of cells that are used, its locaton can be because it has a higher density than at resolutons well below the optcal measured using STIM or PIF. Figure the surrounding cytoplasm. There difracton limit. The system allows 3 shows several images of HeLa cells is some evidence in the STIM image us to measure density maps and to that have been grown in a medium that nanodiamonds are accumulatng simultaneously “count” nanopartcles containing fuorescent nanodiamonds around the nucleus. This can be easily in cells. We have applied the new that are approximately 100 nm in confrmed in the alpha partcle induced system to various studies including dimension. In this experiment, we fuorescence image (see Figure 3B) the uptake of gold nanopartcles, wanted to look at the uptake of these that shows a cluster of nanodiamonds nanodiamonds and rare earth doped in the cell. Figure 3C shows an optcal upconversion nanopartcles. Andrew A. BETTIOL is an Associate Professor with the Department of Physics, NUS. He obtained his Ph.D. from the University of Melbourne, Australia in 1999, working on ion beam induced luminescence. He joined NUS in 1999 as a NSTB fellow and later in 2007 as an Assistant Professor. His current research interests include the modifcaton of optcal propertes of materials by ion-beams, fabricaton of nanophotonic materials and sub- difracton limit imaging of whole cells using nuclear microscopy and radiobiology. References [1] Betol AA, et al., “High-resoluton fast ion microscopy of single whole biological cells” APPLIED PHYSICS REVIEWS Volume: 3 Issue: 4 Artcle Number: 041102 DOI: 10.1063/1.4971414 Published: 2016. [2] Mi ZH, et al., “ Subwavelength imaging through ion-beam-induced upconversion” NATURE COMMUNICATIONS Volume: 6 Artcle Number: 8832 DOI: 10.1038/ncomms9832 Published: 2015. [3] Chen X, et al., “High-Resoluton 3D imaging and quantfcaton of gold nanopartcles in a whole cell using scanning transmission ion microscopy” BIOPHYSICAL JOURNAL Volume: 104 Issue: 7 Pages: 1419-1425 DOI: 10.1016/j. bpj.2013.02.015 Published: 2013. ADVANCES IN SCIENCE | VOL. 22 | NUMBER 1 | JUNE 2017 7
   4   5   6   7   8   9   10   11   12   13   14