A Bioglass‐Poly(lactic‐co‐glycolic Acid) Scaffold@Fibrin Hydrogel Construct to Support Endochondral Bone Formation

Abstract

AbstractBone tissue engineering using stem cells to build bone directly on a scaffold matrix often fails due to lack of oxygen at the injury site. This may be avoided by following the endochondral ossification route; herein, a cartilage template is promoted first, which can survive hypoxic environments, followed by its hypertrophy and ossification. However, hypertrophy is so far only achieved using biological factors. This work introduces a Bioglass‐Poly(lactic‐co‐glycolic acid@fibrin (Bg‐PLGA@fibrin) construct where a fibrin hydrogel infiltrates and encapsulates a porous Bg‐PLGA. The hypothesis is that mesenchymal stem cells (MSCs) loaded in the fibrin gel and induced into chondrogenesis degrade the gel and become hypertrophic upon reaching the stiffer, bioactive Bg‐PLGA core, without external induction factors. Results show that Bg‐PLGA@fibrin induces hypertrophy, as well as matrix mineralization and osteogenesis; it also promotes a change in morphology of the MSCs at the gel/scaffold interface, possibly a sign of osteoblast‐like differentiation of hypertrophic chondrocytes. Thus, the Bg‐PLGA@fibrin construct can sequentially support the different phases of endochondral ossification purely based on material cues. This may facilitate clinical translation by decreasing in‐vitro cell culture time pre‐implantation and the complexity associated with the use of external induction factors.