3D printed self-lubricating bionic cartilage

Inspired by the natural lubrication mechanism of articular cartilage, this study presents a novel self-lubricating bionic cartilage scaffold fabricated through an advanced extrusion-based 3D printing technique that integrates a frozen platform and dot-matrix printing. The primary innovation lies in the rational structural design of a biomimetic porous scaffold capable of mimicking both boundary and fluid film lubrication, enabling autonomous lubricant release under radial compression. A biphasic “lubrication–storage–release” system was constructed by incorporating graphene oxide (GO) and a hyaluronic acid/Pluronic F127 (H/F) lubricant. GO enhanced the hydrogel’s mechanical strength, with the G1P group (GO/Polyvinyl Alcohol (PVA) composite, 1 mg/mL GO) achieving a tensile strength of 3.02 ± 0.27 MPa and a compressive modulus comparable to natural cartilage (≈1.8 MPa). The H/F component significantly improved tribological properties, reducing the friction coefficient of GO/PVA composite, 1 mg/mL GO-hyaluronic acid/Pluronic F127 (G1P-H/F) to 0.053 ± 0.004. In vivo evaluation using a rabbit cartilage defect model demonstrated excellent repair efficacy, with the GO-H/F group showing a 64.8 % reduction in osteophyte volume and maintaining bone microstructure parameters (Bone Volume/Total Volume Trabecular Separation (BV/TV， Tb.Sp)) similar to those of the sham group. These findings confirm the crucial role of the bionic glandular cavity architecture in achieving sustained lubrication and promoting cartilage regeneration, offering a promising strategy for the precision fabrication of functional artificial cartilage.