Mechanicalproperties And Histocompati -bility Of Carbonfibre Reinforced Nano -hydroxyapatite/Polyamide66 Biocomposite

Part ⅠMechanical properties of carbon fibre reinforced nano-hydroxyapatite/polyamide 66 biocompositeObjective:To investigate the Mechanical properties of carbon fibre reinforced nano-hydroxyapatite/polyamide 66 (CF-r-HA/PA66) composite and compare with mechanical properties of nano-hydroxyapatite/polyamide66 (n-HA/PA66) composite. Background and methods:In the present study, a series of novel ternary compositeswere prepared using carbon fibre (CF) to reinforce nano-hydroxyapatite/polyamide66 (n-HA/ PA66) composites.The interface and mechanical strength of the ternary composites (CF-r-HA/PA66) and nano-hydroxyapatite/polyamide66 composites(n-HA/PA66) were characterized and compared.Results:It was found that the CFs distributed evenly into the n-HA/PA66 matrix with no preferred orientation. In addition,the CFs bonded tightly with the n-HA/PA66,and no cracks were observed between the CFs and the n-HA/PA66 matrix.The results indicated that CFs had good compatibility with the n-HA/PA66 matrix,which was considered to be evidence of a reinforced material with improved mechanical properties compared to that of the matrix.In the present study,the addition of CFs was used to enforce n-HA/P A66;the obtained ternary composite exhibited a compressive strength of 116-212MPa,a bending strength of 89-138MPa and a tensile strength of 109-181 MPa,with breaking elongation of 6.2-9.1%,and a modulus of 2.9-5.8GPa,with the values varying with the CF contents.It is obvious that the addition of CFs significantly improved the mechanical properties of the n-HA/PA66 composite. Furthermore,the compressive,bending and tensile strength of 20CF-r-HA/PA66 were higher than those of bone,while its modulus was close to that of natural bone.Conclusion:The incorporation of CF into n-HA/PA66 composite improved the strength and ductility.Hence,the CF-r-HA/PA66 ternary composite haspotential to be used as a bone repair materials and fixation device. Part ⅡIn vivo biocompatibility of carbon fiber reinforednano-hydroxyapatite/polyamide66 compositesObjective:To investigate the histocompatibility of Carbon fiber-reforced-hydrox-yapatite/polyamide66 (CF-r-HA/PA66) composite and nano-hydroxyapatite/polya-mide66 (n-HA/PA66) composite.Methods:In vivo experiment were estimated for the histocompatibility of CF-r-HA/PA66 and n-HA/PA66 as follows.Eight Bama miniature swines were taken to establish the thoracic vertebral bone defectrepare mode. At the time points of 8,16 and 24 weeks after operation,8 animals were sacrificed, respectively. The group of CF-r-HA/PA66 was the experiment sides and n-HA/PA66 was the control.Bone mineral density was measured.The bone defect site underwent HE staining.Blood samples for kidney and liver function tests were taken at the point of before operation,1 week and 8 weeks after operation.Results:HE staining of bone sample showed that the materials could bond with the bone defect interface without reject reaction,and could induce osteogenesis of chondrocytes. At 8 weeks after surgery,new bone trabecula was detected. At 16 weeks after surgery, the new bone trabecula connected.At 24 weeks after surgery,bone trabecula in the internal composite began to rebuilded and connected,and cartilage cell in the composite suggested that the internal composite active bone-formation.Bone mineral density results show that the two groups’BMD increased with significant differences over the whole period,and had no statistical difference compared with each other at the same time.The liver and kidney function tests showed us that no significant difference before and after operation which implanted the CF-r-HA/PA66 material Conclusion:Preliminary view is that CF-r-HA/PA66 has excellent histocompatibility and osteoinductivity, non-hepatictoxicity and non-nephritic toxicity.