Porous nHA/PA66 Scaffolds: Synergistic research on material structure Breakthroughs and bone repair in vivo

A general overview of the study indicates that it consists of four parts: Raw material preparation and screening; Arburg plastic freeforming techniques; Applications in vivo and bone regeneration effects. • Porous nHA/PA66 scaffolds with micron-sized pores were created via melt deposition and APF printing, showing advantages in bioactivity, mechanical strength, and in vivo bone regeneration. • nHA/PA66 scaffolds were evaluated based on material ratios and pore sizes to optimise biomechanical strength. • A novel 3D porous nHA/PA66 scaffold was developed, addressing high hardness, straightforward blockage of hydroxyapatite, and fine structure processing challenges while maintaining mechanical strength and osteogenic activity. To address the issues of poor pore connectivity and insufficient bone ingrowth in the clinical application of current nHA/PA66 bone graft materials. In this study, nHA:PA66 composites with ratios of 5:5, 6:4, and 7:3 were prepared by melt precipitation, and the optimal ratio was identified using characterisation techniques. Furthermore, four different pore sizes of nHA/PA66 scaffolds were fabricated using the Arburg Plastic Freeforming (APF) technology. The biocompatibility, mechanical properties, and oxygen exchange efficiency of these scaffolds were then evaluated. Then, the porous scaffold was implanted into the rabbit femoral condyle bone defect model, and the osteogenic efficacy was evaluated through Micro-CT, histological, and mechanical. The results indicate that nHA/PA66 (6:4) has high crystallinity, excellent thermal stability, and optimal mechanical properties. Animal experiments have shown that the 400 μm group nHA/PA66 scaffold is superior to other groups in terms of new bone tissue volume and material-bone bonding strength. We believe that nHA/PA66 (6:4), combined with 3D printing technology, can produce optimised porous scaffolds that exhibit optimal osteogenic properties and mechanical adaptability at a pore size of 400 μm. These research findings will provide a basis for promoting the clinical transformation and application of nHA/PA66 porous scaffolds.