Directional Topography Influences Adipose Mesenchymal Stromal Cell Plasticity: Prospects for Tissue Engineering and Fibrosis

Abstract

Introduction. Progenitor cells cultured on biomaterials with optimal physical-topographical properties respond with alignment and differentiation. Stromal cells from connective tissue can adversely differentiate to profibrotic myofibroblasts or favorably to smooth muscle cells (SMC). We hypothesized that myogenic differentiation of adipose tissue-derived stromal cells (ASC) depends on gradient directional topographic features. Methods. Polydimethylsiloxane (PDMS) samples with nanometer and micrometer directional topography gradients (wavelength w=464-10, 990 nm; amplitude a=49-3, 425 nm) were fabricated. ASC were cultured on patterned PDMS and stimulated with TGF-β1 to induce myogenic differentiation. Cellular alignment and adhesion were assessed by immunofluorescence microscopy after 24 h. After seven days, myogenic differentiation was examined by immunofluorescence microscopy, gene expression, and immunoblotting. Results. Cell alignment occurred on topographies larger than w=1758 nm/a=630 nm. The number and total area of focal adhesions per cell were reduced on topographies from w=562 nm/a=96 nm to w=3919 nm/a=1430 nm. Focal adhesion alignment was increased on topographies larger than w=731 nm/a=146 nm. Less myogenic differentiation of ASC occurred on topographies smaller than w=784 nm/a=209 nm. Conclusion. ASC adherence, alignment, and differentiation are directed by topographical cues. Our evidence highlights a minimal topographic environment required to facilitate the development of aligned and differentiated cell layers from ASC. These data suggest that nanotopography may be a novel tool for inhibiting fibrosis.

Topography-driven alterations in endothelial cell phenotype and contact guidance

“…The mixed directional topography showed ASC alignment on the directional topography (Figure 7b, Supplementary information video 12) while random orientations were observed on the flat part (Supplementary information Figure 4). This was similar to our earlier findings [25]. Additionally, at 41 h post-seeding of the ECs, they had formed limited networks on the ASCs monolayer of the flat areas but not on the ASCs on the topography.…”

“…They showed that healthy and diseased (diabetic) human coronary artery endothelial cells responded differently to the PDMS substrates studied. We only evaluated one type of endothelial cell in our gradient system, but previously we have also used the same gradient to identify the behavior of myoblasts [26] and a similar gradient to identify the behavior of ASCs [25] finding that indeed various cell types result in different alignment and differentiation patterns. Future research should include other types of endothelial cells on our topographical gradient to study if the network formation is reproducible among endothelial cells and characterize what are the specific features for each cell type and their relationship between healthy and diseased patients.…”

“…ECs have been aligned by using: nanofibrils made of 30-50 nm collagen I fibers [13]; micropatterns mostly made of fibronectin with 2.5 μm-100 μm stripes [14,15,16]; microgrooves with ridges and grooves ranging from 200 nm to 10 μm and depths of 50 nm to 5 μm [17,18,19,20,21]; and fewer topographies with sinusoidal features with 20 μm wavelength and 6.6 μm amplitude [22]. Previously, we have shown that directional gradients can be used for screening the morphological and phenotypical response of osteoblasts [23,24], adipose tissue-derived stromal cells (ASCs) [25], and myoblasts [26]. Cell phenotype is significantly affected by topography, which has differing effects depending on the cell type.…”

Molecular and Biomechanical Clues From Cardiac Tissue Decellularized Extracellular Matrix Drive Stromal Cell Plasticity

“…The cytoskeleton was stained by Phalloidin Alexa Fluor R 488 (1:400; green; ThermoFisher, Waltham, USA) and nuclei were stained with DAPI (4 µg/ml; #D9542-5MG, blue; Sigma-Aldrich, St. Louis, USA). SM22α expression was calculated by the normalized total cell fluorescence (CTCF) method as previously described (McCloy et al, 2014;Liguori et al, 2019), and plotted as the fold-change relative to the nonstimulated tissue culture plastic control. Briefly, the corrected total cell fluorescence (CTCF) is calculated as the integrated density (ID) subtracted of the product between the area covered by cells (A) and the mean fluorescence of background readings (B), i.e., CTCF = ID -(A × B).…”

The Density of Perineuronal Nets Increases With Age in the Inferior Colliculus in the Fischer Brown Norway Rat

“…There are numerous studies that have investigated the link between aging and increases in oxidative stress (see review Liguori et al, 2019). PNs are also known to protect neurons against oxidative stress (Morawski et al, 2004;Suttkus et al, 2012Suttkus et al, , 2014Cabungcal et al, 2013).…”