Graphene oxide coated three-dimensional printed biphasic calcium phosphate scaffold for angiogenic and osteogenic synergy in repairing critical-size bone defect

The custom-tailored medicine requires a developmental strategy that integrates excellent osteogene-sis with mechanical stability to enhance the reconstruction of the critical-size bone defect(CSBD)and the healing process in weight-bearing bone.We prepared three-dimensional(3D)printed biphasic cal-cium phosphate(BCP)scaffolds composited with nano-graphene oxide(GO).The biological effects of the GO/BCP composite scaffolds could induce the differentiation of rat bone marrow stem cells(BM-SCs)and the migration of human umbilical vein endothelial cells(HUVECs)for bone repair.The proper ratio of GO in the composite scaffold regulated the composites’surface roughness and hydrophilicity to a suitable range for the adhesion and proliferation of BMSCs and HUVECs.Besides,the GO/BCP composite scaffold increased osteogenesis and angiogenesis by activating BMP-2,RUNX-2,Smad1/4,and VEGF.The customized intramedullary nail combined with GO/BCP scaffold was applied to repair CSBD(2.0 cm in length)in a beagle femur model.This fixation strategy was confirmed by finite element analysis.In vivo,the results indicated that the custom-made internal fixation provided sufficient stability in the early stage,ensuring bone healing in a considerable mechanical environment.At 9 months postoperatively,longitudi-nal bony union and blood vessels in osteon were observed in the CSBD area with partial degradation in the 0.3%GO/BCP group.In the three-point bending test,the ultimate load of 0.3%GO/BCP group reached over 50%of the normal femur at 9 months after repair.These results showed a promising application of osteogenic GO/BCP scaffold and custom-made intramedullary nails in repairing CSBD of the beagle femur.This effective strategy could provide an option to treat the clinical CSBD in weight-bearing bones.

First application of 3D design custom-made uncemented prosthetic stem for distal femoral cemented megaprosthesis revision

Objectives:3D design,which is widely used in orthopedics,can be applied for precise distal femoral megaprosthetic revision.This research aimed to present and evaluate the design,perioperative management,and midterm clinical outcomes of a 3D design custom-made uncemented prosthetic stem.Methods:Between January 2014 and January 2016,seven patients received 3D design custom-made uncemented prosthetic stem revision at our institution.Clinical records and radiographs were evaluated retrospectively.Results:There were no hardware-related complications during the follow-up(average 24.3 months;range 24–48 months).The average Musculoskeletal Tumor Society(MSTS)score at the last follow-up after revision(27.7 points,range 25–28 points)was significantly higher than that before(16.0 points,range 13–18 points).In addition,the range of motion(ROM)of the affected knee,and the scores of pain,function,emotional acceptance,support,walking and gait all improved significantly.The antecurvature radian of the revision stem averaged at 3.6°.Of the seven patients,three received femoral stem revision and four received revision of the femoral stem and the femoral component;three of them used longer prostheses than the others.There were no significant differences in function between these two groups at the last follow-up after revision.Conclusion:The 3D design custom-made prosthesis is a typical precision medicine technology in oncologic orthopedics.Characterized by its individually and precisely designed uncemented stem,it offers an alternative option for distal femoral cemented prosthesis revision.Besides the 3D design itself,the perioperative management,especially the techniques for stem implantation,and long-term follow-up are also crucial.