Sandwich-Like Gelatin/Polycaprolactone/Polyvinyl Pyrrolidone 3D Model with Significantly Improved Cartilage Cells Adhesion and Regeneration

A novel sandwich-like composite 3D model integrated with deposited gelatin film and printed polycaprolactone (PCL)/polyvinyl pyrrolidone (PVP) scaffold is proposed for 3D cartilage cell culture. The 3D model includes three layers, top scaffold, middle gelatin film, and basal slide. The printed scaffold layer mimicking extracellular matrix is employed to provide 3D regeneration architecture; gelatin film layer is used for fixing printed scaffold and catching falling cells. Electrospray and electrohydrodynamic jet printing technologies are combined to construct sandwich-like composite 3D model. The blended constructing processes are investigated thoroughly both theoretically and experimentally. The retained charges on the gelatin film are influenced the electric field distribution and jet behaviors during printing. The characteristics of gelatin film and composite scaffold are studied. The thickness, surface roughness, and planeness of one layer of deposited gelatin film are 400 nm, 22 nm, and 2.27 mu m; the size of printed PCL/PVP composite fiber is 10 mu m. The fabricated sandwich-like composite 3D model is proved to facilitate adhesion and ingrowth of cartilage cells.