Clin Hemorheol Microcirc. 2019 Sep 19. doi: 10.3233/CH-199206. [Epub ahead of print]

The Effect of stiffness variation of electrospun fiber meshes of multiblock copolymers on the osteogenic differentiation of human mesenchymal stem cells.

Sun X^1,2, Tung W¹, Wang W¹, Xu X¹, Zou J^1,3, Gould OEC¹, Kratz K¹, Ma N^1,3, Lendlein A^1,2,3.

Abstract

Electrospinning has attracted significant attention as a method to produce cell culture substrates whose fibrous structure mimics the native extracellular matrix (ECM). In this study, the influence of E-modulus of fibrous substrates on the lineage commitment of human adipose-derived stem cells (hADSCs) was studied using fiber meshes prepared via the electrospinning of a polyetheresterurethane (PEEU) consisting of poly(ρ-dioxanone) (PPDO) and poly(ɛ-caprolactone) (PCL) segments. The PPDO: PCL weight ratio was varied from 40:60 to 70:30 to adjust the physiochemical properties of the PEEU fibers. The cells attached on stiffer PEEU70 (PPDO:PCL,= 70:30) fiber meshes displayed an elongated morphology compared to those cultured on softer fibers. The nuclear aspect ratio (width vs. length of a nucleus) of hADSCs cultured on softer PEEU40 (PPDO:PCL = 40:60) fibers was lower than on stiffer fibers. The osteogenic differentiation of hADSCs was enhanced by culturing on stiffer fibers. Compared to PEEU40, a 73% increase of osteocalcin expression and a 34% enhancement of alkaline phosphatase (ALP) activity were observed in cells on PEEU70. These results demonstrated that the differentiation commitment of stem cells could be regulated via tailoring the mechanical properties of electrospun fibers.