Preparation And Properties Of BT/HA/PHBV Micro Nanofibers Film

With the development of bone tissue engineering,the preparation of biodegradable composite scaffolds with good properties is necessary.Hydroxyapatite（HA）is used in bone scaffold material as a main mineral phase commonly.However,the mechanical property of single HA is poor.The strength of bone scaffold can be improved by composite HA with organic polymer materials.PHBV as a new biopolymer material,has become an excellent material for bone scaffold due to its excellent mechanical properties,biodegradability,and biocompatibility.Barium titanate（BaTiO₃）,is a piezoelectric ceramic,can effectively promote bone regeneration when it acts on bone defects.The porous structure of bone scaffold is beneficial to the growth,proliferation and differentiation of bone tissue.Based on this,this paper proposes to synthesize BT/HA/PHBV three-dimensional porous micro nanofiber bone scaffolds,realize the complementary advantages between components.Meanwhile,the porous structure and coordination of scaffolds,greatly improve the mechanical properties and biological activity of composite scaffolds,and prepare bone scaffolds with excellent biodegradability.1.The phases transformation of BaTiO₃ is realized by hydrothermal method in high concentration alkaline solution by adjusting the influence factors of hydrothermal.The single tetragonal phase BaTiO₃ is prepared.The optimal hydrothermal conditions of BaTiO₃phase transformation are explored by response surface design（BBD）.The results showed that the optimal hydrothermal conditions are alkali content 16 g,hydrothermal time 48 h and hydrothermal temperature 195℃.2.The tetragonal BT/HA composite nanoparticles can be prepared by the best hydrothermal conditions successfully.BT/HA/PHBV micro nanofibers film can be obtained by electrospinning.The mechanical,piezoelectric,and biological properties of BT/HA/PHBV3.BT/HA/PHBV micro nanofibers film has the highest ultimate strength of 2.80688±0.29MPa,which meets the requirements of mechanical properties of micro nanofiber bone scaffold;it has excellent biological activity and biodegradability.After soaking in 5×SBF（simulated body fluid）solution for 36 h,the micro nanofibers film surface is completely covered by hydroxyapatite,and the mass change rate is 198.36%.After soaking in 10×PBS（phosphate buffer）solution for 36 h,obvious degradation signs such as mottling and shedding could be seen on the micro nanofibers film surface,and the mass change rate was 12.20%;The hydrophilic angle of BT/HA/PHBV micro nanofibers film is almost 0°and has good hydrophilicity,which is conducive to cell adhesion,proliferation and differentiation;it has no cytotoxicity and excellent biocompatibility;it has excellent piezoelectric properties,and the piezoelectric coefficient d₃₃ value is 1.06 p C/N.4.The combination model of BT/HA/PHBV is studied by Gaussion simulation.The degradation mechanism of BT/HA/PHBV micro nanofibers film was revealed by simulation.The prepared BT/HA/PHBV micro nanofibers film can meet the performance requirements of bone tissue engineering scaffold materials,and is suitable for bone defect repair,which has a bright research prospect.