posted on 2021-04-16, 16:06authored byKe Deng, Ping Du, Kun Liu, Xuelian Tao, Javad Harati, Jhe-Wei Jhang, Jua Kim, Peng-Yuan Wang
Hybrid
surfaces with tunable topography, chemistry, and stiffness
have potential to rebuild native extracellular matrix (ECM) and manipulate
cell behavior in vitro. However, the fabrication of controllable hybrid
surfaces is still challenging. In this study, colloidal self-assembly
technology was used to program particles into highly ordered structures
with hybrid chemistry and stiffness at biointerfaces. These colloidal
self-assembled patterns (cSAPs), including unary, binary, and ternary
cSAPs, composed of silicon (Si), polystyrene (PS), and/or poly(N-isopropylacrylamide) (pNIPAM) nanogels (PNGs), were fabricated
using either coassembly or layer-by-layer (LBL) methods. The selected
binary cSAPs (i.e., PS/PNG and PNG/PS) have a tunable surface topography
and wettability between 25 and 37 °C; thus, they can be used
as dynamic cell culture substrates. Human adipose-derived mesenchymal
stem cells (hASCs), bone marrow-derived mesenchymal stem cells (hBMSCs),
and macrophages (THP-1) were investigated on these hybrid cSAPs under
a static or dynamic system. The results showed that hybrid cSAPs significantly
influenced the focal adhesions, cell morphology, cell migration, and
gene expressions of stem cells. In general, stem cells had more vinculin
puncta, smaller spreading size, and faster migration speed than the
TCPS control. Hybrid cSAPs up-regulated gene expressions of focal
adhesion kinase (FAK) and chondrocytes (AGG and SOX9) under static
culture, while they also up-regulated osteocytes (COL1 and RUNX2)
under dynamic culture. THP-1 macrophages were at M0 state on all cSAPs
under static culture. However, cells became sensitive under dynamic
culture. For example, some M1 genes (i.e., IL6, CD68, and TNFα)
and M2 genes (i.e., IL10 and CD206) were down-regulated, while other
M1 genes (i.e., IL1β) and M2 genes (i.e., TGF-β and IL1ra)
were up-regulated, depending on the particle combinations. In conclusion,
new hybrid cSAPs with thermoresponsive surface properties are versatile
materials for stem cells and macrophages manipulation.