Biomimetic design and fabrication of thermally induced radial gradient shape memory scaffolds using fused deposition modeling (FDM) for bone tissue engineering

Bone defects pose a significant challenge, often exceeding natural healing capabilities. This study explores the potential of thermally induced radial gradient shape memory (RGSM) scaffolds for minimally invasive bone repair. Inspired by the natural porosity gradient of bone, these scaffolds feature a high-porosity inner zone that mimics cancellous bone and a low-porosity outer zone that resembles cortical bone. When the relationship between porosity and key properties was investigated, it was found that lower-porosity RGSM scaffolds exhibited higher compressive strength but experienced higher residual strain and lower shape recovery ratio compared to their higher-porosity counterparts. Despite this trade-off, the gradient design successfully mimicked the natural bone structure, potentially enhancing osseointegration and bone regeneration. These results demonstrate the feasibility of RGSM scaffolds for bone tissue engineering. This holds promise for advancing minimally invasive surgical techniques and improving the treatment of bone defects.