Effect of Topography and Physical Stimulus on hMSC Phenotype Using a 3D In Vitro Model

This communication reports a comparative 3D in vitro model examining how scaffold architecture (aligned electrospun PCL nanofibres alone vs nanofibre/collagen hydrogel laminate composites) and cyclic tensile loading jointly regulate human mesenchymal stem cell (hMSC) phenotype over 7 days. Across conditions, hMSCs in contact with aligned fibres oriented parallel to fibre direction, indicating strong topographical guidance. In laminate composites, static culture promoted hMSC migration from the fibre/gel interface into the collagen layer (up to ~500 µm by day 7) and reduced alignment, whereas cyclic tensile stimulation maintained cells predominantly at the fibre/gel interface and preserved alignment cues. Gene expression analysis (qRT-PCR) showed stimulus-dependent lineage-associated responses: mechanically loaded composites upregulated RUNX2 (osteogenic), VEGF (angiogenic), and TNC (tenogenic) relative to static composites and loaded fibres, while cartilage markers (SOX9,COL2A1) and elastin (ELN) showed limited or no benefit from the composite environment. Overall, the results highlight that combining microstructural organization with controlled mechanical loading can steer MSC localization and bias multi-lineage phenotypic signaling in composite scaffolds.