ab9b00991_si_001.pdf (1.75 MB)
Nanotopographical Surfaces for Regulating Cellular Mechanical Behaviors Investigated by Atomic Force Microscopy
journal contribution
posted on 2019-09-10, 18:43 authored by Mi Li, Ning Xi, Yuechao Wang, Lianqing LiuCell–substrate
interactions play an important role in regulating
cellular physiological and pathological processes, and therefore,
investigating cell–substrate interface is meaningful for understanding
the behaviors of cells. However, so far, the underlying mechanisms
which guide the nanoscopic biological activities taking place at the
cell–substrate interface remain poorly understood. The advent
of atomic force microscopy (AFM) provides a powerful tool for characterizing
the structures and properties of native biological and biomaterial
systems with unprecedented spatiotemporal resolution, which offers
new possibilities for understanding the physical sciences of biomaterials.
Here, AFM was utilized to unravel the nanotopographical surfaces for
regulating cellular behaviors on three different substrates (glass
slide, mica, and Petri dish). First, the decellularized substrates
prepared with the use of ammonia and trypsin were imaged by AFM, significantly
showing the nanogranular substances on the decellularized substrates
as well as the cell membrane patches for uncovering the detailed situations
of mechanical contact between cells and substrates. Next, experiments
performed on chemically fixed substrates with the use of paraformaldehyde
together with AFM time-lapse imaging remarkably showed that nanogranular
depositions from the cell culture medium appeared on the substrates
for promoting cell growth. Further, the detailed cell culture medium
components which contribute to the nanogranular depositions are identified.
Finally, the dynamic alterations in surface roughness and mechanical
properties of substrates and cells during cell growth were quantitatively
measured by AFM, revealing the diverse changes of the multiple physical
properties (surface roughness, adhesion force, Young’s modulus,
and relaxation time) during cell–substrate interactions. The
research provides novel insights into the nanotopographical surfaces
for cell–substrate interactions, which will be useful for understanding
cellular behaviors.