In Vitro Investigation Of A Tissue-engineered Cell-Tendon Complex Mimicking Transitional Architecture Orienting Ligament-Bone Incorporation

Background:The transitional ligament-bone interface has been emphasized for the effective graft-bone healing. We postulated that a xenogenic scaffold mimicking gradient fibro-chondro-osteogenetic transition could physiologically promote the ligament-bone incorporation.Purpose:This study aimed to construct and characterize a composite tendon scaffold ofcontinuous and heterogeneous transition peculiarity mimicking the native ligamentinsertion site.Methods and results:A decellularized rabbit Achilles tendon was prepared and designed as a stratifiedscaffold containing three biofunctional regions targeting fibro-chondro-osteogenesis, byintegrating heterogeneous cells, enhanced osteogenic and chondrogenic gene modulationand promoted matrix formation. Characterization in terms of morphology, architecture andbiocompatibility exhibited improved bio-physico-chemical property. The unique formationof the transitional structure was advanced by enhanced delivery of upper-streamtranscription factors of Sox-9and Runx-2, and this adenovirus-based strategy triggeredearly up-regulation of gene and protein profile of cartilage-and bone-relevant markers byquantitative PCR and immunoblot analysis. Besides, gradient tissue-specific matrixcomponent was respectively analysed on predesignated regions via specific histologicalstaining and immunofluorescence.Conclusion:A transitional interface could be replicated on a decellularized exogenic engineeredtendon by stratified integration. This scaffold possessed extraordinary property of multi-tissuse transition architecture of controlled cellular interactions and matrixheterogeneity, which potentially expands the options for the regeneration of ligament-boneinterface.