3D Printed Gelatin-alginate Bioactivescaffolds Combined With Mice Bone Marrowmesenchymal Stem Cells:a Biocompatibility Study

Objective: This study was aimed to determine the biocompatibility of gelatin-alginate scaffolds with 3D bio-printer and the mice bone marrow mesenchymal stem cells(BMSCs),and the histocompatibility during skin wound healing.Methods: BMSCs was separated and cultured using pan-marrow attachment method and the third generation combined with gelatin-alginate was added to the 3D printer for the preparation of bioactive scaffolds that concluded the BMSCs.Then the following characteristics of BMSCs,including survival?adhesion?aggregation and growth,were observed under inverted microscope and electron microscope.We created the full-thickness skin wound model on the mouse back and observed the wound surface's fusion situation and the corresponding histopathological changes after putting the bioactive scaffolds on the surface.Results:1.The rat bone marrow mesenchymal stem cells were isolated by bone marrow adherence method.Various cells were present in the cell suspension,all of which were in a single cell state.Each kind of cells was approximately spherical,and the bone marrow mesenchymal stem cells were cultured to the first.The third generation and the third generation of cells are also mostly polygonal,with a small number of spindles,swirls,or clusters.2.Using a 3D bioprinter,a bioactive scaffold was prepared from rat bone marrow mesenchymal stem cells and gelatin and sodium alginate as raw materials.3.Under the electron microscope,murine bone marrow mesenchymal stem cells after three days of culture in the scaffold were scattered and adhered to the surface of the scaffold.The adherence was good and the cells were evenly distributed.4.Under light microscope,the mesenchymal stem cells in the scaffold can be seen in the initial growth of the stent attached to the obvious growth,the distribution is still uniform,single or small clusters,polygonal or long shuttle,and in the culture bottle The growth state is the same.5.In this experiment,the defect of the whole back layer of the mouse was prepared,the wound diameter was 1cm,the texture of the bioactive scaffold was soft,and after being cut according to the shape and size of the wound,it was covered in the wound of the mouse and the stent and the wound tissue were completely attached.Attached.Under histological observation,with the healing of wounds,inflammatory cells exuded into the interior of the stent,which promoted the formation of granulation tissue,the stent gradually dissolved,and the new granulation tissue gradually thickened to the 14 th day after wounding.Epithelial cells cover the entire surface of the wound.The granulation tissue begins to age and form collagen-rich scars.The wounds basically heal.Conlusion: 1.3D printing uses gelatin-alginate alginate as the printing medium and carries bone marrow mesenchymal stem cells.Gelatin and sodium alginate are ideal biological materials,which are conducive to cell adhesion,absorb wound exudation,promote inflammatory reactions,and accelerate wound healing.As a scaffold for cell culture.2.Bone marrow mesenchymal stem cells grow well in the bioactive scaffold,and the growth state is closer to the morphological appearance in the culture fluid,which shows that the biological scaffold has no effect on the growth state of the adherent cells,and the cells can adhere on the scaffold.And proliferation.3.Overall,the results suggest that the 3D-printed bioactive scaffold carrying the BMSCs has good biocompatibility and is safe for skin tissue engineering without rejection and biotoxicity.This provides a theoretical basis for the clinical application of active stents.Bioprinting technology is a fascinating technology for the revolution of biomedical research and industry.In the future,active stents will surely gain more research progress in skin tissue engineering.