Biocompatibility Evaluation Of GelMA-based Gelatin Microspheres Hydrogel Scaffold

Bone is a highly vascularized tissue.Due to the clinical interventions,diseases,and the accidents etc,bone defects have been affecting the quality of human life.At present,autologous bone transplantation and allograft bone transplantation are the "gold standard" for the treatment of bone defects.".However,the complications of the donor site and the disease spreading limit the method of "gold standard".In recent years,bone tissue engineering has been well developed.More and more materials are applied to bone repair.Bone tissue engineering includes three elements: seed cells that generate bone tissue,some factors that regulate cell growth,and bone tissue engineering scaffolds.Current materials for prepared scaffold are mainly concentrated on naturally derived materials as well as some synthetic materials.Among them,gelatin is widely used in bone tissue engineering.Object : Gelatins have been widely used in tissue engineering.However,the submicron-or nanosized polymer networks of Hydrogels severely limit cell growth and tissue formation.In order to resolve this issue,a GelMA-based gelatin microspheres hydrogel scaffold(named GelMA-GMs)is developed and its biocompatibility was also detected.Methods : Fabricating the GelMA-GMs hydrogel scaffold.Using MTT assay,hemolytic test,living/dead cell and DAPI staining to assess the biocompatibility of GelMA-GMs scaffold with BMSCs.Inverted phase microscope was used to observe and scaffold structure.PCR were conducted to investigate the osteogenic ability.Results: Prepared Gel MA-GMs hydrogel scaffold looks like milky in appearance.Inverted phase microscopy showed that the BMSCs grew well in the GelMA-GMs hydrogel scaffold extract.The MTT results showed that no significance difference between the absorbance value of the scaffold extract group and the control group(P > 0.05),and the cytoxicity level of the GelMA-GMs hydrogel scaffold is grade 1.The hemolytic test showed that hemolysis rate GelMA-GMs scaffold extract is 1.23%(<5%).The living/dead cell and DAPI staining indicated that BMSCs proliferate well on GelMA-GMs hydrogel scaffold.Inverted phase microscopy showed that GelMA-GMs hydrogel scaffold posses the porous structure and the diameter of the micropore is 200 um.PCR showed that osteoblastic differentiation PCR showed that MSCs-encapsulated scaffolds presented good osteogenic differentiation,using the osteoblast inducing conditional media served as the culture media.Conclusion: The GelMA-GMs hydrogel scaffold has a good biocompatibility and showed a promising biomaterial for bone defects.