3D-printed vancomycin-eluting PGCL/MXene bifunctional scaffold for management of infected bone defects

The clinical management of infected bone defects remains a significant challenge in orthopedic surgery. In this study, we developed a multifunctional composite scaffold by integrating MXene (Ti 3 C 2 ) nanosheets and vancomycin (Van) into a degradable poly(glycolide-co-caprolactone) (PGCL) polymer through precision 3D printing technology, with the aim of regenerating acutely infected bone defects. Systematic optimization established the optimal composition as 5 wt% Ti 3 C 2 and 5 wt% Van within the degradable PGCL polymer. Compared with PGCL scaffolds, a significantly thicker mineralized layer could be deposited on the PGCL@5 %Ti 3 C 2 /5 %Van surface in simulated body fluid (SPF). The in vitro results showed that the PGCL@5 %Ti 3 C 2 /5 %Van scaffold had antibacterial properties, cytocompatibility, osteoblast differentiation and extracellular mineralization. The in vivo results showed that the PGCL@5 %Van/5 %Ti 3 C 2 scaffold effectively inhibited infection caused by methicillin-resistant Staphylococcus aureus (MRSA) in bone defects and promoted bone repair. The potential mechanism of Ti 3 C 2 in anti-inflammatory and osteogenic induction was investigated through transcriptome analysis. These results suggest that Ti 3 C 2 is involved in the regulation of the PI3K‒Akt signalling pathway to increase osteogenic induction ability and regulate the inflammatory response by downregulating the NF-κB pathway through the deiodinase iodothyronine type II (DiO2). These findings indicate that the PGCL@5 %Ti 3 C 2 /5 %Van scaffold can enhance the regeneration of acutely infected bone defects.