| AVS 61st International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI+AS-TuA |
| Session: | Characterization of Biointerfaces |
| Presenter: | Xin Hua, Pacific Northwest National Laboratory |
| Authors: | X. Hua, Pacific Northwest National Laboratory C. Szymanski, Pacific Northwest National Laboratory Z.Y. Wang, Pacific Northwest National Laboratory B.W. Liu, Pacific Northwest National Laboratory Z. Zhu, Pacific Northwest National Laboratory J.E. Evans, Pacific Northwest National Laboratory G. Orr, Pacific Northwest National Laboratory S.Q. Liu, Southeast University, China X.Y. Yu, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Mammalian cell analysis is of significant importance in providing detailed insights into biological system activities. Due to the complexity and heterogeneity of mammalian cell behavior and the technical challenge of spatially mapping chemical components in a hydrated environment, correlated chemical imaging from multiplexed measurement platforms is needed. Fluorescence structured illumination microscope (SIM), with super high resolution and visualization of proteins and sub-cellular structures in 3-D, provides more detailed information in cell imaging. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a unique surface-sensitive analytical tool that provides molecular information and chemical mapping with a sub-micron lateral resolution. However, the understanding of how the spatial heterogeneity and structural difference affect the mammalian cell activities in an unperturbed, hydrated state by ToF-SIMS is severely limited due to the challenge to detect liquids with high volatility under high vacuum environment using surface sensitive technique like ToF-SIMS.
We recently developed a novel microfluidic reactor for C10 mouse lung epithelial cell growth for SIM imaging and direct probing of hydrated cell in vacuum using ToF-SIMS. C10 cells were inoculated into the microchannel, incubated at 37 oC for 24 hr., fed with 5 nM quantum dots, and then fixed with 4% paraformaldehyde before SIM imaging. In subsequent ToF-SIMS analysis, an aperture of 2 µm in diameter was drilled through SiN membrane to form the detection window to image biological surfaces directly; and surface tension is used for holding the liquid within the aperture.
SIM images show that C10 cells are successfully cultured on the SiN membrane, and quantum dots are uptaken by cells and dispersed in the cytoplasm. The ToF-SIMS m/z spectra showing characteristic fragments of dried cell sample, hydrated cells, and uninoculated medium in the microreactor will be presented. Moreover, 2D images of representative cell fragments and quantum dots ion mapping will be discussed. In addition, depth profiling will be used to provide time- and space-resolved imaging of the cells inside the microchannel. Furthermore, principal component analysis is conducted to evaluate the intrinsic similarities and discriminations among samples. Our results demonstrate feasibility for in situ imaging of cells in the hydrated state using ToF-SIMS for the first time. Correlative imaging using SIM and ToF-SIMS provides information across different space scales for investigating cell dynamics. This novel approach has great potential for studying intracellular processes in the future.