posted on 2019-12-12, 12:36authored byYong Hou, Leixiao Yu, Wenyan Xie, Luis Cuellar Camacho, Man Zhang, Zhiqin Chu, Qiang Wei, Rainer Haag
Material surface topographic features have been shown
to be crucial
for tissue regeneration and surface treatment of implanted devices.
Many biomaterials were investigated with respect to the response of
cells on surface roughness. However, some conclusions even conflicted
with each other due to the unclear interplay of surface topographic
features and substrate elastic features as well as the lack of mechanistic
studies. Herein, wide-scale surface roughness gradient hydrogels,
integrating the surface roughness from nanoscale to microscale with
controllable stiffness, were developed via soft lithography with precise
surface morphology. Based on this promising platform, we systematically
studied the mechanosensitive response of human mesenchymal stem cells
(MSCs) to a broad range of roughnesses (200 nm to 1.2 μm for Rq) and different substrate stiffnesses. We observed
that MSCs responded to surface roughness in a stiffness-dependent
manner by reorganizing the surface hierarchical structure. Surprisingly,
the cellular mechanoresponse and osteogenesis were obviously enhanced
on very soft hydrogels (3.8 kPa) with high surface roughness, which
was comparable to or even better than that on smooth stiff substrates.
These findings extend our understanding of the interactions between
cells and biomaterials, highlighting an effective noninvasive approach
to regulate stem cell fate via synergetic physical cues.