Stem Cell Proliferation And Osteogenic Differentiation In 3D Printing Polycaprolactone-hydroxyapatite Scaffolds With Multi-scale Porosity Enriched Unprocessed Bone Marrow

The study described a novel multi-scale porosity bone tissue scaffold fabricated by computer-aided, fused deposition modeling 3D printing (FDM-3DP) system to control the macro- and microstructure precisely. The bone marrow stem cells (BMSCs) and cartilage cells seeded on polycaprolactone-hydroxyapatite (PCL-HA) composite scaffolds were cultured under normal medium to test the ability of preliminary biological evaluation. Then the scaffolds enriched with the unprocessed bone marrow (Group A),while the control group (Group B) utilized the BMSCs seeded PCL-HA scaffolds, were cultured under osteogenic medium for 28 days to test the ability of osteogenic in vitro. The research indicated that scaffolds possessed predesigned, well-ordered and interconnected micropores for the attachment and proliferation of BMSCs and cartilage cells. After cultured 72 h, the relative density of BMSCs and cartilage cells within the scaffolds were significant higher than cells in culture plate. The mineralization, alkaline phosphatase (ALP) activity, up-regulated genes of osteogensison and Alizarin Red S staining indicated that Group A are more bioactive than Group B in vitro (P< 0.05).Our results indicated that the PCL-HA scaffold which had bone-mimetic environment, enriched with unprocessed bone marrow proved to be resulted in more cell adhesion and better bone regeneration. It was proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The PCL-HA-UBM multi-scale porosity scaffold is a candidate for future bone regeneration studies.