Atomic force acoustic microscopy reveals the influence of substrate stiffness and topography on cell behavior

Abstract

The stiffness and the topography of the substrate at the cell–substrate interface are two key properties influencing cell behavior. In this paper, atomic force acoustic microscopy (AFAM) is used to investigate the influence of substrate stiffness and substrate topography on the responses of L929 fibroblasts. This combined nondestructive technique is able to characterize materials at high lateral resolution. To produce substrates of tunable stiffness and topography, we imprint nanostripe patterns on undeveloped and developed SU-8 photoresist films using electron-beam lithography (EBL). Elastic deformations of the substrate surfaces and the cells are revealed by AFAM. Our results show that AFAM is capable of imaging surface elastic deformations. By immunofluorescence experiments, we find that the L929 cells significantly elongate on the patterned stiffness substrate, whereas the elasticity of the pattern has only little effect on the spreading of the L929 cells. The influence of the topography pattern on the cell alignment and morphology is even more pronounced leading to an arrangement of the cells along the nanostripe pattern. Our method is useful for the quantitative characterization of cell–substrate interactions and provides guidance for the tissue regeneration therapy in biomedicine.

Chemically Crosslinked Methylcellulose Substrates for Cell Sheet Engineering

“…On this topic, Mih et al revealed the insensitiveness of L929 cells to substrates with stiffnesses in the 0.1–100 kPa range [ 49 ], comparable to the one investigated in the present study. Moreover, even substrates with higher E ranges (i.e., in the order of MPa) have been reported not to influence the spreading and the shape of L929 cells seeded on them [ 50 ]. Since the present study was intended as a bench test for crosslinked MC substrates to evaluate their responsive behavior in the field of CSE, the obtained outcomes should not be considered unfavorable.…”

Combining atomic force microscopy with complementary techniques for multidimensional single‐cell analysis

“…The results 117 demonstrate the uniqueness of SNFUH to image the internal structures of cell and the fine structures along cell periphery, which is useful for understanding the life activities of single cells. There are now commercially available products for realising the simultaneous AFM and ultrasound imaging of specimens (http://www.afm.cn), which have been utilised to the studies of single cells 123,124 . Nevertheless, it should be noted that so far SNFUH works well for simple biological systems such as RBCs (Figure 4B) which do not have organelles and specimens which have regular multilayer structures (Figure 4A).…”

Development of a polyacrylamide/chitosan composite hydrogel conduit containing synergistic cues of elasticity and topographies for promoting peripheral nerve regeneration

“…7 In addition to physical signals, substrate elasticity and topography are two of the most critical physical cues in regulating cell functions and tissue regeneration. 8 The elasticity of biomaterials is a crucial factor in constructing the microenvironment during tissue regeneration. 9 Previous studies have shown that cell behavior is regulated by matrix elasticity, which plays an important role in mechanical transduction.…”