The Research Of PDPCs With Zinc-containing TCP/PLLA Scaffold In Repairing Bone Defect

It’s a tendency to use tissue engineering bone to repair segmental bone defect in orthopaedic research. Scaffolds, seed cells and growth factors are regarded as three elemens in tissue engineering. Thus, we fabricated a novel zinc-containing porous TCP/PLLA scaffolds to support periosteum-derived progenitor cells (PDPCs) in bone tissue engineering by osteoinduction and inflammatory response suppression. We found that zinc-containing TCP/PLLA scaffolds had a good biocompatibility and controlled release of zinc ions. When either RAW264.7 macrophage-like cells or PDPCs were cultured in the scaffolds containing 0%,5% and 10% of zinc, the expression level of pro-inflammatory cytokines including IL-6 and TNF-a was down-regulated, but that of the osteogenic specific genes was increased dose-dependently. After implanted in subcutaneous site for 3 days, zinc-containing TCP/PLLA scaffolds showed significantly fewer neutrophils and lymphocytes, especially in 5%Zn group. Then we evaluated the effect of scaffolds in bone regeneration by implanting in a cranial bone defects. The results suggested that 5% zinc-containing TCP/PLLA scaffolds had a superior ability in the repair of bone. In conclusion, our study highlights the potential of proper concentration zinc-containing TCP/PLLA scaffolds in bone tissue engineering, as well as developing a future therapy for critical sized bone defect regeneration by utilizing zinc-containing TCP/PLLA scaffolds combined with PDPCs.