Building a degradable scaffold with 3D printing using Masquelet technique to promote osteoblast differentiation and angiogenesis in chronic tibial osteomyelitis with bone defects

The aim of this study was to investigate the use of three-dimensional (3D) printing technology to create a biodegradable scaffold loaded with WNT5A protein and assess its impact on chronic tibial osteomyelitis with bone defects (CTO&BD), focusing on osteoblast differentiation and angiogenesis. We extracted RNA from peripheral blood of healthy individuals and CTO&BD patients for sequencing, followed by differential expression and functional enrichment analysis. Network analysis was performed to identify core genes associated with CTO&BD and construct a protein–protein interaction network. Using Masquelet technique, we fabricated a 3D-printed biodegradable scaffold (G40T60@WNT5A) and conducted various experiments, including rheological testing, printability evaluation, Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy analysis, as well as mechanical and degradation performance assessments. In in vivo experiments, we observed the formation of induced membranes in a CTO&BD rat model implanted with the scaffold. In vitro experiments involved the assessment of scaffold toxicity on rat bone marrow mesenchymal stem cells and umbilical vein endothelial cells, as well as the influence on osteoblast differentiation and angiogenesis. Molecular biology techniques were used to analyze gene and protein expression levels. We discovered for the first time that WNT5A may play a crucial role in CTO&BD. The biodegradable scaffold prepared by 3D printing (G40T60@WNT5A) exhibited excellent biocompatibility in vitro. This scaffold significantly promoted the formation of induced membranes in CTO&BD rats and further enhanced osteoblast differentiation and angiogenesis. In conclusion, this study utilized innovative 3D printing technology to fabricate the G40T60@WNT5A scaffold, confirming its potential application in the treatment of CTO&BD, particularly in promoting osteoblast differentiation and angiogenesis. This research provides new methods and theoretical support for the treatment of bone defects.