Study On The Performance Of 3D Bio-composite Scaffold Based On Human Periodontal Ligament Stem Cells Printing Technique

Objective:To study the physical and biological properties of 3D bio-composite scaffold based on human periodontal ligament stem cell(h PDLSCs)printing technique.Methods:(1)mixing sodium alginate(SA),gelatin(Gel)and nano-hydroxyapatite(na-HA)into hydrogels to test its rheological properties by Kinexus Pro advanced rotational rheometer to identify the optimal printing slurry for printing.(2)Preparing SA/Gel/na-HA bio-composite scaffolds by 3D bioplotter and characterizing the physical properties of scaffolds(morphology and structure,swelling and mechanical property).(3)Mixing h PDLSCs with SA/Gel/na-HA printing slurry as “bioink” to print SA/Gel/na-HA/h PDLSCs cell scaffold and that of biocompatibility and osteogenic differentiation performances were tested by using live/dead cell staining,cell adhesion,cell proliferation and alkaline phosphatase activity.Results:(1)The viscosity of SA/Gel/na-HA composite hydrogel was 248.3pa·s.(2)The SEM showed that these bio-composite scaffolds were three dimensional porous structure and rough surface with obvious particles;The equilibrium swelling of the scaffold was 125.9%;And the compression stress was 0.671 MPa,the compression elastic modulus was 8.27 Kpa.SA/Gel/Na-HA/h PDLSCs cell scaffolds showed good cell survival by staining the lived/dead cells;Cell adhered well;The results of CCK-8 showed that there was a significant difference in the absorbance values of the scaffold on 2d,4d and 6d(P<0.05);The ALP activity of cell scaffolds on 14 d was significantly higher than that on 7d(P<0.05).Conclusions:(1)The SA/Gel/n-HA composite hydrogel had good rheological properties to be used suitablely for printing.(2)Suitable swelling rate and certain pore structure helped the cells in exchanging nutrients and excreting metabolites.Adding the na-HA could improve the mechanical properties of the bio-composite scaffolds,which make the scaffolds have better mechanical properties.(3)The SA/Gel/na-HA/h PDLSCs cell scaffolds caused effective stimulation of cell survival,adhesion,proliferation and osteoblast differentiation.Therefore,the SA/Gel/na-HA/h PDLSCs cell scaffolds displayed great potential to become a new material for bone defect reconstruction.