Abstract:

In order to architecturally and functionally mimic native Extracellular Matrix (ECM), a novel micro/nano-fibrous scaffold of hydroxyapetite/poly(lactide-co-glycolide) (HA/PLGA) composite was successfully prepared by melt-spinning method. A porous three-dimensional scaffold fabricated by melt-molding particulate-leaching method was used as control. This kind of scaffold comprising both nanofiber and microfiber had an original structure including a nano-network favorable for cell adhe-sion, and a micro-fiber providing a strong skeleton for support. The microfibers and nanofibers were blended homogeneously in scaffold and the compression strength reached to 6.27 MPa, which was close to human trabecular bone. The typical mi-cro/nano-fibrous structure was more beneficial for the proliferation and differentiation of Bone Mesenchymal Stem Cells (BMSCs). The calcium deposition and Alkaline Phosphatase (ALP) activity were evaluated by the differentiation of BMSCs, and the results indicated that the temporary ECM was very beneficial for the differentiation of BMSCs into maturing osteoblasts. For repairing rabbit radius defects in vivo, micro/nano-fibrous scaffold was used for the purpose of rapid bone remodeling in the defect area. The results showed that a distinct bony callus of bridging was observed at 12 weeks post-surgery and the expression of osteogenesis-related genes (bone-morphogenetic protein-2, Osteonectin, collagen-I) increased because of the ECM-like structure. Based on the results, the novel micro/nano-fibrous scaffold might be a promising candidate for bone tissue engi-neering.

Key words: PLGA-based scaffold, melt-spinning, nano/micro-fibers, bone tissue engineering