The Effect Of Aligned PHBHHx Fibers On Differentiation Of Bone Marrow Mesenchymal Stem Cells

Cell-matrix interaction was functionally essential for phenotypicmaintenance and multipotency remodeling of stem cells. For bone tissueengineering, electrospinning techniques are useful to create fibrous scaffoldsmimicking natural mineralized collagen fibrous structure in bone. In thisstudy, effect of electrospun fiber alignment on MSCs differentiation potentialwas investigated on PHBHHx electrospun meshes. Compared withrandomly-oriented ones, the aligned fiber orientation increased elasticmodulus and tension stress of the PHBHHx meshes. Most of the attachedMSCs elongated along the aligned fibers.From the transcriptome microarray results, there were a total of67differentially expressed genes between aligned and random groups, and mostof them were involved in cell adhesion and actin cytoskeleton regulation. Inaddition, PPAR signaling pathway was reduced on the aligned fibers, whichmight contribute to the impaired adipogenesis and enhanced osteogenesis. Itwas further confirmed by RT-PCR and western blotting.The PPARγ downregulation on the aligned fibers was related tophosphorylated activation of ERK, with no effect on total ERK expression.However, the induction of osteogenic differentiation by PHBHHx fiberalignment was relatively less significant that it could only support initialadipo-osteogenic switch and would be partially covered up by osteogenic oradipogenic soluble inductive chemicals.The use of electrospinning technology to fabricate aligned PHBHHxmeshes or even three-dimensional scaffolds with aligned surface will bepromising for the osteo-inductive implant materials.