3D Cell Printing Of Functional Cartilage Matrix Constructs Using PLA Nanofibers Scaffold Integrating With Chondrocytes

Background:Cartilage regeneration has been one of major challenging issues in orthopaedics medicine owing to the poor intrinsic ability for repair.Tissue engineering techniques provide an optional method for the treatment of cartilage matrix defects by generating substitutable structures.The evolution of 3D printed polylactic acid(PLA)scaffold implants in vivo has not been reported.Method:PLA nanofibers scaffold integrating with chondrocytes were observed in vitro experiments,including immunofluorescence,toluidine blue staining,safranin staining and qPCR.Then they were transplanted under the central tissue of femur cartilage after building model of cartilage drilling hole in two groups respectively.They were observed through the method of scanning electron microscopy,immunofluorescence and vivo research after 4weeks and 8weeks after the surgery.Result:Chondrocytes grew well on PLA scaffolds,and the relative quantification of F-actin,aggrecan and type ? collagen was significantly increased.In vivo results showed that cartilage tissue proliferated and extended in the scaffold over time,cartilage thickness increased,and the scaffold area gradually became thinner.Conclusion:The newborn cartilage matrix in matrix extended along the border of cartilage and scaffold and matured in sequence.The collagen in matrix expanded and interlaced.The scaffold in matrix collapsed step by step.Those findings indicated that 3D printing PLA nanofibers may be potentially utilized for construction of the cartilage matrix.