Efficacy of hESC-MSCs in knitted silk-collagen scaffold for tendon tissue engineering and their roles

Human embryonic stem cells (hESC) and their differentiated progenies are an attractive cell source for transplantation therapy and tissue engineering Nevertheless the utility of these cells for tendon tissue engineering has not yet been adequately explored This study incorporated hESC-derived mesenchymal stem cells (hESC-MSCs) within a knitted silk-collagen sponge scaffold and assessed the efficacy of this tissue-engineered construct in promoting tendon regeneration When subjected to mechanical stimulation in vitro hESC-MSCs exhibited tenocyte-like morphology and positively expressed tendon-related gene markers (e g Collagen type I & III Epha4 and Scleraxis) as well as other mechano-sensory structures and molecules (cilia integrins and myosin) In ectopic transplantation the tissue-engineered tendon under in vivo mechanical stimulus displayed more regularly aligned cells and larger collagen fibers This in turn resulted in enhanced tendon regeneration in situ as evidenced by better histological scores and superior mechanical performance characteristics Furthermore cell labeling and extracellular matrix expression assays demonstrated that the transplanted hESC-MSCs not only contributed directly to tendon regeneration but also exerted an environment-modifying effect on the implantation site in situ Hence tissue-engineered tendon can be successfully fabricated through seeding of hESC-MSCs within a knitted silk-collagen sponge scaffold followed by mechanical stimulation (C) 2010 Elsevier Ltd All rights reserved