Matrix Determines MSC Shape

One decellularized rat testis scaffold gave the same bone-marrow mesenchymal stem cells three strikingly different shapes. After 3 days, cells in the interstitium looked fibroblast-like, cells inside seminiferous tubules were spherical and showed mitoses, and cells on the tunica albuginea were squamous. The scaffold had been stripped of cells while preserving tubules, matrix proteins, and overall architecture. Researchers seeded 5×10⁴ third-passage rat MSCs per scaffold and cultured them for 7 days. Three-dimensional viability rose from day 1 to day 7 and became comparable with two-dimensional culture. The experiments show location-specific cell form; they suggest that each matrix compartment provides distinct spatial cues. Architecture can become an instruction for a cell.