Study On Degradation And Mineralization Of Boron-doped Bioglass

Bioglass,as a representative of a new generation of inorganic biomaterials,has been receiving much attention since it was discovered by Professor Hench in the United States in1969.Traditional bioglass is prepared by high-temperature melting method.In order to further enhance the biological activity of bioglass and expand the composition of the material,the sol-gel method is applied to the preparation of bioglass materials,and the bioglass materials prepared by the sol-gel method have higher biological activity.When bio-glass is soaked in body fluid,hydroxyapatite?HA?is formed on the surface.HA is an important component of human bones,which promotes the combination of bone tissue and bio-glass materials.In addition,the study also found that the particles released by bioglass in body fluids have the effect of stimulating gene expression,which further illustrates the importance of bioglass materials in the biomedical field.In this paper,boron-doped bioactive glass,bio-ceramic glass and mesoporous bioglass materials were prepared by sol-gel method and sol-gel-template method.The materials were detected by XRD,FTIR,SEM and TEM to explore the properties of the materials.Soaking in vitro simulated experiments can be used to detect the biological activity of the material.In this paper,the prepared material is immersed in simulated body fluid?SBF?for 15 days,and SBF is extracted at a fixed time point for detection to analyze the degradation process of the material.After the SBF soaking experiment,the material properties were tested again,and the changes before and after the material immersion were analyzed to investigate the effect of boron doping on the bioactivity and degradation properties of the material.The bioglass obtained by heat treatment at 600°C is amorphous,and the doping of boron changes the grid structure of bioglass.As the content of boron replaces silicon,the number of boron[SiO₄]cells in the glass structure decreases.The increase in the number of[BO₃]and[BO₄]units reduces the chemical stability of the glass and promotes the release of silicon.The release of silicon promotes the formation of hydroxyapatite on the surface of the bioglass,which increases the activity of the bioglass.After heat treatment at 800?,crystallites were formed in the bioglass material,HA and CaSiO₃ crystals appeared in the boron doped material,and only HA crystal appeared in the boron-undoped material.After soaking in the SBF solution for 15 days,only HA crystals were present in the five samples,and the B-doped samples contained more HA crystals.In addition,we have prepared mesoporous bioglass materials by sol-gel-template method.The prepared material has a particle size of 200-400 nm and contains a large number of disordered mesoporous structures.During culturing in vitro,boron doped materials produced HA after cultivation,while the undoped boron mesoporous bioglass material produced HA and a non-degradable calcite crystal phase.The experimental results show that the doping of boron enhances the biological activity of bioglass materials and bioglass materials,and has a certain influence on the particle size of nano-mesoporous materials prepared by sol-gel method.