Culturing Cells on Flexible Substrates of High Refractive Indexes
- PDF / 259,218 Bytes
- 7 Pages / 432 x 648 pts Page_size
- 41 Downloads / 177 Views
Culturing Cells on Flexible Substrates of High Refractive Indexes You-Ren Liu and Po-Ling Kuo Department of Electric Engineering, Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, 10617, Taiwan ABSTRACT Mechanical cues in cellular microenvironment are central in directing a class of cellular behaviors such as the dynamic of cell adhesion, migration, and differentiation. Several advanced optical techniques, such as structured-illumination nano-profilometry (SINAP), have been developed for a better resolution of these dynamic processes. These techniques however require culturing cells on materials of refractive index close to that of glass, while most studies regarding the effects of mechanical cues on cellular dynamics were conducted on hydrogel-based substrates. Here we report the development of culturing substrates of tunable rigidity and refractive index suitable for SINAP studies. Polyvinyl chloride (PVC)-based substrates were mixed with a softener called Di(isononyl) Cyclohexane-1,2-Dicarboxylate (DINCH) and cured by heating. The volume ratios of PVC to DINCH were varied from 1:1 to 3:1. The Young’s modulus of the resulting substrates ranged from 18 kPa to 40 kPa. The yielded refractive indices of the composite substrates as measured by phase contrast tomography ranged from 1.47 to 1.53. Human lung adenocarcinoma cells CL1-5 were cultured on the composite substrates and cell viability was examined using the MTT assay. The dynamics of cell adhesion and filopodia activities were examined using SINAP. Preliminary results suggest that PVC based culturing substrates have a great potential in the application of SINAP based studies. INTRODUCTION Cell migration plays a key role in various physiological and pathological processes, such as tissue development, wound healing, angiogenesis, inflammation, and cancer metastasis[1]. A migrating cell is characterized by dynamic protrusions at the cell periphery, namely the lamillopodia and filopodia [1, 2]. Numerous lines of evidence suggest that the dynamic of these cellular protrusions are intimately regulated by the mechanical properties of environment [3-8]. For example, a recent study reveals that filopodia contracted at different periodicity with respect to various compliances of culturing substrates, which may be related to the cell motility and migration velocity [9]. Quantitative analysis of the dynamic of the cellular protrusions requires the aid of advanced optic techniques, such as structured-illumination nano-profilometry (SINAP) [10]. The central concept of SINAP is the combination of structured-illumination microscopy and differential height images. By projecting a two-dimensional periodic excitation pattern into the specimens, optical sections are obtained with improved lateral resolution beyond the diffraction limit. Furthermore, as the specimen is placed into the linear region of the optical sectioning axial response curve, the surface height of the sections can be calculated by the sharp slope of the linear re
Data Loading...
