3D printed Bouncy Bioglass enhances articular cartilage regeneration.

Articular cartilage is an avascular tissue with limited intrinsic repair capacity, and untreated defects will deteriorate progressively over time. Lining the ends of bones, it plays a critical role in joint lubrication and shock absorption. Current surgical interventions, such as microfracture, typically result in the formation of mechanically inferior fibrocartilage. There remains a significant unmet clinical need for biomaterials that can support the regeneration of functional articular cartilage. We present a non-cytotoxic sol-gel hybrid scaffold, of composition silica/poly(tetrahydrofuran)/polycaprolactone (SiO2/PTHF/PCL-diCOOH), termed 'Bouncy Bioglass' to address that need. Our ovine model revealed that Bouncy Bioglass scaffolds with 250 μm channels stimulated hyaline cartilage regeneration. They outperformed scaffolds with 500 μm channel and microfracture alone, by improved integration and filling of the defect site with articular-like cartilage tissue. This tissue showed a significant increase in collagen type II and other primary components of healthy articular cartilage, compared to the tissue formed from the other two conditions. Our hybrid biomaterial, Bouncy Bioglass, enhances the regeneration of articular cartilage and may offer an 'off-the-shelf' synthetic implant option to treat localised articular defects and prevent their continued degeneration.