Cell secreted matrices (CSM), especially extracellular matrix proteins (ECM) deposited by cells, has drawn attention in recent years in bio-material studies. Studying such matrices can help us to understand cell-substract interactions and find the cues of the cell adhesion, differentiation and proliferation mechanisms on material surfaces. It is known that surface characteristics such as hydrophilicity, surface potential, rigidity, and etc. affected the composition and the morphology of ECM that in turn altered the cell behaviors. In particular, self-assembled monolayers (SAMs) are known for their convenience and versatile to modify the surface. A series of zeta potential can be obtained by introducing two kinds of functional groups to gold surface, namely 6-amino-1-hexanethiol and 6-mecraptohexanoic acid. In previous works, these serial surfaces were found to cause different adhesion behaviors for HEK 293T epithelial and NIH 3T3 fibroblast cells. The cells can adhere and extend faster on surfaces of higher zeta potential. However, the results also showed that the morphological characteristics as the function of time were different between these cells. However, ECM-associated adhesion mechanisms in these systems were not yet clear. In this study, CSM created by NIH 3T3 fibroblast or HEK 293T cells seeded on binary SAM modified gold surface were examined. After incubation, the decellularized matrices were immune-stained for ECM proteins, including collagen IV, laminin and fibronectin, to determine the retained basement layer. In addition, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to generate hyperspectral images for each CSM surfaces. This surface sensitive technique allows for revealing the distribution of molecules on the outmost several nanometers of the exposed CSM. To extract the trends from the complex hyperspectrum, multivariate analysis, namely principle component analysis (PCA) was employed. As the results, the immune-stained CSM images and SIMS ion image revealed that surface potential affected the ECM protein deposition. Moreover, the difference of ECM composition between two cell types was discussed.

Revealing the effect of zeta potential in cell secreted extracellular matrix with time-of-flight secondary ion mass spectrometry

251st National Meeting (2016)

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