Objective:To observe whether transforming growth factor-beta 1 (TGF-β1) can improve the mechanical properties of tissue engineered heart valve (TEHV) prepared by TGF-β1 and myofibroblasts.Methods: Myofibroblasts were isolated,cultured,identified,and seeded onto the decellularized aortic valve leaflet.In the experimental group,TEHV were cultured with DMEM containing 10 ng/ml TGF-β1 for 14 days.In the control group,TEHV were cultured with DMEM only for 14 days.The contents of lysyl oxidase (LOX) and hydroxyproline,the expression of LOX and COLL-1 mRNA,and the mechanical properties of the TEHVs were analyzed in each group.Results: The contents of LOX and hydroxyproline,expression of LOX and COLL-1 mRNA,Max-load,and Max-stress were significantly higher in the experimental group than those in the control group (all P<0.05).However,the experimental and control group showed comparable values of Max-strain and elastic modulus.Conclusion: TGF-β1 can increase expression of LOX and COLL-1 mRNA in the seeded cells during TEHV construction,increasing the production and cross-linking of collagen,and improve the mechanical properties of the TEHV.