Bi-layered Nano Active Implant with Hybrid Stem Cell Microtissues for Tuned Cartilage Hypertrophy

Abstract

Repair of articular cartilage defects remains challenging, as a majority of these defects reach the subchondral bone. The objectives of this work were first, to develop a new advanced therapeutic implant for osteoarticular repair, and second, to prevent hypertrophy of the articular cartilage region. For this aim, we developed a bi-compartmented implant, presenting a first layer for subchondral bone regeneration: Compartment 1, composed of a nanofibrouspoly (ε−caprolactone) membrane equipped with BMP-7 growth factor nanoreservoirs, second layer for cartilage regeneration: Compartment 2, composed of alginate/ hyaluronic acid hydrogel. To modulate hypertrophy, compartment 2 was seeded with microtissues of human mesenchymal stem cells co-cultured with human chondrocytes as differentiation inductors. This new strategy offers an appropriate double 3D environment (microtissues in Hydrogel) as inductive trigger for cartilage regeneration with tuned hypertrophy.