The Experimental Research Of Different Scaffold Seeded By Rabbit Bone Marrow Mesenchymal Stem Cell Incorporation With Hyper Baricoxygen To Repair Rabbit Radial Bone Defect With Seawater Immersion

Objectives To investigate the therapeutic efficacy of bone marrow mesenchymal stem cells(BMSCs) seeding in different scaffold combination with hyperbaric oxygen(HBO) to repair rabbit radius defect immersed by seawater.Methods A 15 mm radius defect were made in 45 rabbits, and then wound limbs were immersed in seawater for 3 h. So the rabbit model of bone defect immersed by seawater was established. All rabbits were randomly divided into 4 groups,which were group A, group B, group C, and group D. BMSCs were implanted in group A, autogenous bone were implanted in group B, β-TCP/gelatin/BMSCs were implanted group C, and n-HA/gelatin/BMSCs were implanted into group D. Each rabbits received HBO for 14 days after surgery. X-ray, hostologic, immunohistochemical and mechanical analysis were used to evaluate the therapeutic efficacy in each groups.Results(1) X-ray: after 4 weeks after surgery, bone defect area in A, B, C,D group had thin cloudy callus shadow, shadow area in group B> group D > group C > group A. After 8 weeks, a small amount of callus formation in group A; a large amount of new bone callus formation in B, C and D group. After 12 weeks, in group A the repairment of bone defect unfinished; in group B bone defect was compeletly repaired with good cortical continuity, recanalizated marrow cavity and good cortical plasticity; bone defect was basically completed to repair in group C with good cortical continuity, bone defect was basically completed to repair in group D with good cortical continuity, recanalizated marrow cavity.(2) Bone callus grey value : after surgery 12 weeks,bone callus grey value in groups A, B, C, and D was respectively 109.1±2.2, 213.4±2.7,195.8±2.6 and 207.3±4.1(P<0.05).(3) HE staining indicated the formation of bone trabecula in group B>group D > group C> group A, and residual scaffold material could be found at surgery 4 weeks. After 8 weeks, no lamellar bone formated in group A, a large number of lamellar bone formated in group B, C and D. After 12 weeks, A small amount of lamellar bone formated in group A; a large number of lamellar bone formated in group B, C and D, and residual materials in two groups were completely degraded.(4) Biomechanical testing showed that after surgery 12 weeks the maximum bending force in group B > that in group D >that in group C >that in group A, in addition to Group C and group D were close to group B.Conclusion( 1) Scaffold of n-HA/gelatin/BMSCs and beta-TCP/gelatin incorporation with HBO were effective to treat seawater immersed bone defect,(2)n-HA/gelatin was excellent than beta-TCP/gelatin.